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Differences Between: [Versions 39 and 310] [Versions 39 and 311] [Versions 39 and 400] [Versions 39 and 401] [Versions 39 and 402] [Versions 39 and 403]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * This file contains classes used to manage the navigation structures within Moodle.
  19   *
  20   * @since      Moodle 2.0
  21   * @package    core
  22   * @copyright  2009 Sam Hemelryk
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  defined('MOODLE_INTERNAL') || die();
  27  
  28  /**
  29   * The name that will be used to separate the navigation cache within SESSION
  30   */
  31  define('NAVIGATION_CACHE_NAME', 'navigation');
  32  define('NAVIGATION_SITE_ADMIN_CACHE_NAME', 'navigationsiteadmin');
  33  
  34  /**
  35   * This class is used to represent a node in a navigation tree
  36   *
  37   * This class is used to represent a node in a navigation tree within Moodle,
  38   * the tree could be one of global navigation, settings navigation, or the navbar.
  39   * Each node can be one of two types either a Leaf (default) or a branch.
  40   * When a node is first created it is created as a leaf, when/if children are added
  41   * the node then becomes a branch.
  42   *
  43   * @package   core
  44   * @category  navigation
  45   * @copyright 2009 Sam Hemelryk
  46   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  47   */
  48  class navigation_node implements renderable {
  49      /** @var int Used to identify this node a leaf (default) 0 */
  50      const NODETYPE_LEAF =   0;
  51      /** @var int Used to identify this node a branch, happens with children  1 */
  52      const NODETYPE_BRANCH = 1;
  53      /** @var null Unknown node type null */
  54      const TYPE_UNKNOWN =    null;
  55      /** @var int System node type 0 */
  56      const TYPE_ROOTNODE =   0;
  57      /** @var int System node type 1 */
  58      const TYPE_SYSTEM =     1;
  59      /** @var int Category node type 10 */
  60      const TYPE_CATEGORY =   10;
  61      /** var int Category displayed in MyHome navigation node */
  62      const TYPE_MY_CATEGORY = 11;
  63      /** @var int Course node type 20 */
  64      const TYPE_COURSE =     20;
  65      /** @var int Course Structure node type 30 */
  66      const TYPE_SECTION =    30;
  67      /** @var int Activity node type, e.g. Forum, Quiz 40 */
  68      const TYPE_ACTIVITY =   40;
  69      /** @var int Resource node type, e.g. Link to a file, or label 50 */
  70      const TYPE_RESOURCE =   50;
  71      /** @var int A custom node type, default when adding without specifing type 60 */
  72      const TYPE_CUSTOM =     60;
  73      /** @var int Setting node type, used only within settings nav 70 */
  74      const TYPE_SETTING =    70;
  75      /** @var int site admin branch node type, used only within settings nav 71 */
  76      const TYPE_SITE_ADMIN = 71;
  77      /** @var int Setting node type, used only within settings nav 80 */
  78      const TYPE_USER =       80;
  79      /** @var int Setting node type, used for containers of no importance 90 */
  80      const TYPE_CONTAINER =  90;
  81      /** var int Course the current user is not enrolled in */
  82      const COURSE_OTHER = 0;
  83      /** var int Course the current user is enrolled in but not viewing */
  84      const COURSE_MY = 1;
  85      /** var int Course the current user is currently viewing */
  86      const COURSE_CURRENT = 2;
  87      /** var string The course index page navigation node */
  88      const COURSE_INDEX_PAGE = 'courseindexpage';
  89  
  90      /** @var int Parameter to aid the coder in tracking [optional] */
  91      public $id = null;
  92      /** @var string|int The identifier for the node, used to retrieve the node */
  93      public $key = null;
  94      /** @var string The text to use for the node */
  95      public $text = null;
  96      /** @var string Short text to use if requested [optional] */
  97      public $shorttext = null;
  98      /** @var string The title attribute for an action if one is defined */
  99      public $title = null;
 100      /** @var string A string that can be used to build a help button */
 101      public $helpbutton = null;
 102      /** @var moodle_url|action_link|null An action for the node (link) */
 103      public $action = null;
 104      /** @var pix_icon The path to an icon to use for this node */
 105      public $icon = null;
 106      /** @var int See TYPE_* constants defined for this class */
 107      public $type = self::TYPE_UNKNOWN;
 108      /** @var int See NODETYPE_* constants defined for this class */
 109      public $nodetype = self::NODETYPE_LEAF;
 110      /** @var bool If set to true the node will be collapsed by default */
 111      public $collapse = false;
 112      /** @var bool If set to true the node will be expanded by default */
 113      public $forceopen = false;
 114      /** @var array An array of CSS classes for the node */
 115      public $classes = array();
 116      /** @var navigation_node_collection An array of child nodes */
 117      public $children = array();
 118      /** @var bool If set to true the node will be recognised as active */
 119      public $isactive = false;
 120      /** @var bool If set to true the node will be dimmed */
 121      public $hidden = false;
 122      /** @var bool If set to false the node will not be displayed */
 123      public $display = true;
 124      /** @var bool If set to true then an HR will be printed before the node */
 125      public $preceedwithhr = false;
 126      /** @var bool If set to true the the navigation bar should ignore this node */
 127      public $mainnavonly = false;
 128      /** @var bool If set to true a title will be added to the action no matter what */
 129      public $forcetitle = false;
 130      /** @var navigation_node A reference to the node parent, you should never set this directly you should always call set_parent */
 131      public $parent = null;
 132      /** @var bool Override to not display the icon even if one is provided **/
 133      public $hideicon = false;
 134      /** @var bool Set to true if we KNOW that this node can be expanded.  */
 135      public $isexpandable = false;
 136      /** @var array */
 137      protected $namedtypes = array(0 => 'system', 10 => 'category', 20 => 'course', 30 => 'structure', 40 => 'activity',
 138                                    50 => 'resource', 60 => 'custom', 70 => 'setting', 71 => 'siteadmin', 80 => 'user',
 139                                    90 => 'container');
 140      /** @var moodle_url */
 141      protected static $fullmeurl = null;
 142      /** @var bool toogles auto matching of active node */
 143      public static $autofindactive = true;
 144      /** @var bool should we load full admin tree or rely on AJAX for performance reasons */
 145      protected static $loadadmintree = false;
 146      /** @var mixed If set to an int, that section will be included even if it has no activities */
 147      public $includesectionnum = false;
 148      /** @var bool does the node need to be loaded via ajax */
 149      public $requiresajaxloading = false;
 150      /** @var bool If set to true this node will be added to the "flat" navigation */
 151      public $showinflatnavigation = false;
 152  
 153      /**
 154       * Constructs a new navigation_node
 155       *
 156       * @param array|string $properties Either an array of properties or a string to use
 157       *                     as the text for the node
 158       */
 159      public function __construct($properties) {
 160          if (is_array($properties)) {
 161              // Check the array for each property that we allow to set at construction.
 162              // text         - The main content for the node
 163              // shorttext    - A short text if required for the node
 164              // icon         - The icon to display for the node
 165              // type         - The type of the node
 166              // key          - The key to use to identify the node
 167              // parent       - A reference to the nodes parent
 168              // action       - The action to attribute to this node, usually a URL to link to
 169              if (array_key_exists('text', $properties)) {
 170                  $this->text = $properties['text'];
 171              }
 172              if (array_key_exists('shorttext', $properties)) {
 173                  $this->shorttext = $properties['shorttext'];
 174              }
 175              if (!array_key_exists('icon', $properties)) {
 176                  $properties['icon'] = new pix_icon('i/navigationitem', '');
 177              }
 178              $this->icon = $properties['icon'];
 179              if ($this->icon instanceof pix_icon) {
 180                  if (empty($this->icon->attributes['class'])) {
 181                      $this->icon->attributes['class'] = 'navicon';
 182                  } else {
 183                      $this->icon->attributes['class'] .= ' navicon';
 184                  }
 185              }
 186              if (array_key_exists('type', $properties)) {
 187                  $this->type = $properties['type'];
 188              } else {
 189                  $this->type = self::TYPE_CUSTOM;
 190              }
 191              if (array_key_exists('key', $properties)) {
 192                  $this->key = $properties['key'];
 193              }
 194              // This needs to happen last because of the check_if_active call that occurs
 195              if (array_key_exists('action', $properties)) {
 196                  $this->action = $properties['action'];
 197                  if (is_string($this->action)) {
 198                      $this->action = new moodle_url($this->action);
 199                  }
 200                  if (self::$autofindactive) {
 201                      $this->check_if_active();
 202                  }
 203              }
 204              if (array_key_exists('parent', $properties)) {
 205                  $this->set_parent($properties['parent']);
 206              }
 207          } else if (is_string($properties)) {
 208              $this->text = $properties;
 209          }
 210          if ($this->text === null) {
 211              throw new coding_exception('You must set the text for the node when you create it.');
 212          }
 213          // Instantiate a new navigation node collection for this nodes children
 214          $this->children = new navigation_node_collection();
 215      }
 216  
 217      /**
 218       * Checks if this node is the active node.
 219       *
 220       * This is determined by comparing the action for the node against the
 221       * defined URL for the page. A match will see this node marked as active.
 222       *
 223       * @param int $strength One of URL_MATCH_EXACT, URL_MATCH_PARAMS, or URL_MATCH_BASE
 224       * @return bool
 225       */
 226      public function check_if_active($strength=URL_MATCH_EXACT) {
 227          global $FULLME, $PAGE;
 228          // Set fullmeurl if it hasn't already been set
 229          if (self::$fullmeurl == null) {
 230              if ($PAGE->has_set_url()) {
 231                  self::override_active_url(new moodle_url($PAGE->url));
 232              } else {
 233                  self::override_active_url(new moodle_url($FULLME));
 234              }
 235          }
 236  
 237          // Compare the action of this node against the fullmeurl
 238          if ($this->action instanceof moodle_url && $this->action->compare(self::$fullmeurl, $strength)) {
 239              $this->make_active();
 240              return true;
 241          }
 242          return false;
 243      }
 244  
 245      /**
 246       * True if this nav node has siblings in the tree.
 247       *
 248       * @return bool
 249       */
 250      public function has_siblings() {
 251          if (empty($this->parent) || empty($this->parent->children)) {
 252              return false;
 253          }
 254          if ($this->parent->children instanceof navigation_node_collection) {
 255              $count = $this->parent->children->count();
 256          } else {
 257              $count = count($this->parent->children);
 258          }
 259          return ($count > 1);
 260      }
 261  
 262      /**
 263       * Get a list of sibling navigation nodes at the same level as this one.
 264       *
 265       * @return bool|array of navigation_node
 266       */
 267      public function get_siblings() {
 268          // Returns a list of the siblings of the current node for display in a flat navigation element. Either
 269          // the in-page links or the breadcrumb links.
 270          $siblings = false;
 271  
 272          if ($this->has_siblings()) {
 273              $siblings = [];
 274              foreach ($this->parent->children as $child) {
 275                  if ($child->display) {
 276                      $siblings[] = $child;
 277                  }
 278              }
 279          }
 280          return $siblings;
 281      }
 282  
 283      /**
 284       * This sets the URL that the URL of new nodes get compared to when locating
 285       * the active node.
 286       *
 287       * The active node is the node that matches the URL set here. By default this
 288       * is either $PAGE->url or if that hasn't been set $FULLME.
 289       *
 290       * @param moodle_url $url The url to use for the fullmeurl.
 291       * @param bool $loadadmintree use true if the URL point to administration tree
 292       */
 293      public static function override_active_url(moodle_url $url, $loadadmintree = false) {
 294          // Clone the URL, in case the calling script changes their URL later.
 295          self::$fullmeurl = new moodle_url($url);
 296          // True means we do not want AJAX loaded admin tree, required for all admin pages.
 297          if ($loadadmintree) {
 298              // Do not change back to false if already set.
 299              self::$loadadmintree = true;
 300          }
 301      }
 302  
 303      /**
 304       * Use when page is linked from the admin tree,
 305       * if not used navigation could not find the page using current URL
 306       * because the tree is not fully loaded.
 307       */
 308      public static function require_admin_tree() {
 309          self::$loadadmintree = true;
 310      }
 311  
 312      /**
 313       * Creates a navigation node, ready to add it as a child using add_node
 314       * function. (The created node needs to be added before you can use it.)
 315       * @param string $text
 316       * @param moodle_url|action_link $action
 317       * @param int $type
 318       * @param string $shorttext
 319       * @param string|int $key
 320       * @param pix_icon $icon
 321       * @return navigation_node
 322       */
 323      public static function create($text, $action=null, $type=self::TYPE_CUSTOM,
 324              $shorttext=null, $key=null, pix_icon $icon=null) {
 325          // Properties array used when creating the new navigation node
 326          $itemarray = array(
 327              'text' => $text,
 328              'type' => $type
 329          );
 330          // Set the action if one was provided
 331          if ($action!==null) {
 332              $itemarray['action'] = $action;
 333          }
 334          // Set the shorttext if one was provided
 335          if ($shorttext!==null) {
 336              $itemarray['shorttext'] = $shorttext;
 337          }
 338          // Set the icon if one was provided
 339          if ($icon!==null) {
 340              $itemarray['icon'] = $icon;
 341          }
 342          // Set the key
 343          $itemarray['key'] = $key;
 344          // Construct and return
 345          return new navigation_node($itemarray);
 346      }
 347  
 348      /**
 349       * Adds a navigation node as a child of this node.
 350       *
 351       * @param string $text
 352       * @param moodle_url|action_link $action
 353       * @param int $type
 354       * @param string $shorttext
 355       * @param string|int $key
 356       * @param pix_icon $icon
 357       * @return navigation_node
 358       */
 359      public function add($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
 360          // Create child node
 361          $childnode = self::create($text, $action, $type, $shorttext, $key, $icon);
 362  
 363          // Add the child to end and return
 364          return $this->add_node($childnode);
 365      }
 366  
 367      /**
 368       * Adds a navigation node as a child of this one, given a $node object
 369       * created using the create function.
 370       * @param navigation_node $childnode Node to add
 371       * @param string $beforekey
 372       * @return navigation_node The added node
 373       */
 374      public function add_node(navigation_node $childnode, $beforekey=null) {
 375          // First convert the nodetype for this node to a branch as it will now have children
 376          if ($this->nodetype !== self::NODETYPE_BRANCH) {
 377              $this->nodetype = self::NODETYPE_BRANCH;
 378          }
 379          // Set the parent to this node
 380          $childnode->set_parent($this);
 381  
 382          // Default the key to the number of children if not provided
 383          if ($childnode->key === null) {
 384              $childnode->key = $this->children->count();
 385          }
 386  
 387          // Add the child using the navigation_node_collections add method
 388          $node = $this->children->add($childnode, $beforekey);
 389  
 390          // If added node is a category node or the user is logged in and it's a course
 391          // then mark added node as a branch (makes it expandable by AJAX)
 392          $type = $childnode->type;
 393          if (($type == self::TYPE_CATEGORY) || (isloggedin() && ($type == self::TYPE_COURSE)) || ($type == self::TYPE_MY_CATEGORY) ||
 394                  ($type === self::TYPE_SITE_ADMIN)) {
 395              $node->nodetype = self::NODETYPE_BRANCH;
 396          }
 397          // If this node is hidden mark it's children as hidden also
 398          if ($this->hidden) {
 399              $node->hidden = true;
 400          }
 401          // Return added node (reference returned by $this->children->add()
 402          return $node;
 403      }
 404  
 405      /**
 406       * Return a list of all the keys of all the child nodes.
 407       * @return array the keys.
 408       */
 409      public function get_children_key_list() {
 410          return $this->children->get_key_list();
 411      }
 412  
 413      /**
 414       * Searches for a node of the given type with the given key.
 415       *
 416       * This searches this node plus all of its children, and their children....
 417       * If you know the node you are looking for is a child of this node then please
 418       * use the get method instead.
 419       *
 420       * @param int|string $key The key of the node we are looking for
 421       * @param int $type One of navigation_node::TYPE_*
 422       * @return navigation_node|false
 423       */
 424      public function find($key, $type) {
 425          return $this->children->find($key, $type);
 426      }
 427  
 428      /**
 429       * Walk the tree building up a list of all the flat navigation nodes.
 430       *
 431       * @param flat_navigation $nodes List of the found flat navigation nodes.
 432       * @param boolean $showdivider Show a divider before the first node.
 433       * @param string $label A label for the collection of navigation links.
 434       */
 435      public function build_flat_navigation_list(flat_navigation $nodes, $showdivider = false, $label = '') {
 436          if ($this->showinflatnavigation) {
 437              $indent = 0;
 438              if ($this->type == self::TYPE_COURSE || $this->key === self::COURSE_INDEX_PAGE) {
 439                  $indent = 1;
 440              }
 441              $flat = new flat_navigation_node($this, $indent);
 442              $flat->set_showdivider($showdivider, $label);
 443              $nodes->add($flat);
 444          }
 445          foreach ($this->children as $child) {
 446              $child->build_flat_navigation_list($nodes, false);
 447          }
 448      }
 449  
 450      /**
 451       * Get the child of this node that has the given key + (optional) type.
 452       *
 453       * If you are looking for a node and want to search all children + their children
 454       * then please use the find method instead.
 455       *
 456       * @param int|string $key The key of the node we are looking for
 457       * @param int $type One of navigation_node::TYPE_*
 458       * @return navigation_node|false
 459       */
 460      public function get($key, $type=null) {
 461          return $this->children->get($key, $type);
 462      }
 463  
 464      /**
 465       * Removes this node.
 466       *
 467       * @return bool
 468       */
 469      public function remove() {
 470          return $this->parent->children->remove($this->key, $this->type);
 471      }
 472  
 473      /**
 474       * Checks if this node has or could have any children
 475       *
 476       * @return bool Returns true if it has children or could have (by AJAX expansion)
 477       */
 478      public function has_children() {
 479          return ($this->nodetype === navigation_node::NODETYPE_BRANCH || $this->children->count()>0 || $this->isexpandable);
 480      }
 481  
 482      /**
 483       * Marks this node as active and forces it open.
 484       *
 485       * Important: If you are here because you need to mark a node active to get
 486       * the navigation to do what you want have you looked at {@link navigation_node::override_active_url()}?
 487       * You can use it to specify a different URL to match the active navigation node on
 488       * rather than having to locate and manually mark a node active.
 489       */
 490      public function make_active() {
 491          $this->isactive = true;
 492          $this->add_class('active_tree_node');
 493          $this->force_open();
 494          if ($this->parent !== null) {
 495              $this->parent->make_inactive();
 496          }
 497      }
 498  
 499      /**
 500       * Marks a node as inactive and recusised back to the base of the tree
 501       * doing the same to all parents.
 502       */
 503      public function make_inactive() {
 504          $this->isactive = false;
 505          $this->remove_class('active_tree_node');
 506          if ($this->parent !== null) {
 507              $this->parent->make_inactive();
 508          }
 509      }
 510  
 511      /**
 512       * Forces this node to be open and at the same time forces open all
 513       * parents until the root node.
 514       *
 515       * Recursive.
 516       */
 517      public function force_open() {
 518          $this->forceopen = true;
 519          if ($this->parent !== null) {
 520              $this->parent->force_open();
 521          }
 522      }
 523  
 524      /**
 525       * Adds a CSS class to this node.
 526       *
 527       * @param string $class
 528       * @return bool
 529       */
 530      public function add_class($class) {
 531          if (!in_array($class, $this->classes)) {
 532              $this->classes[] = $class;
 533          }
 534          return true;
 535      }
 536  
 537      /**
 538       * Removes a CSS class from this node.
 539       *
 540       * @param string $class
 541       * @return bool True if the class was successfully removed.
 542       */
 543      public function remove_class($class) {
 544          if (in_array($class, $this->classes)) {
 545              $key = array_search($class,$this->classes);
 546              if ($key!==false) {
 547                  // Remove the class' array element.
 548                  unset($this->classes[$key]);
 549                  // Reindex the array to avoid failures when the classes array is iterated later in mustache templates.
 550                  $this->classes = array_values($this->classes);
 551  
 552                  return true;
 553              }
 554          }
 555          return false;
 556      }
 557  
 558      /**
 559       * Sets the title for this node and forces Moodle to utilise it.
 560       * @param string $title
 561       */
 562      public function title($title) {
 563          $this->title = $title;
 564          $this->forcetitle = true;
 565      }
 566  
 567      /**
 568       * Resets the page specific information on this node if it is being unserialised.
 569       */
 570      public function __wakeup(){
 571          $this->forceopen = false;
 572          $this->isactive = false;
 573          $this->remove_class('active_tree_node');
 574      }
 575  
 576      /**
 577       * Checks if this node or any of its children contain the active node.
 578       *
 579       * Recursive.
 580       *
 581       * @return bool
 582       */
 583      public function contains_active_node() {
 584          if ($this->isactive) {
 585              return true;
 586          } else {
 587              foreach ($this->children as $child) {
 588                  if ($child->isactive || $child->contains_active_node()) {
 589                      return true;
 590                  }
 591              }
 592          }
 593          return false;
 594      }
 595  
 596      /**
 597       * To better balance the admin tree, we want to group all the short top branches together.
 598       *
 599       * This means < 8 nodes and no subtrees.
 600       *
 601       * @return bool
 602       */
 603      public function is_short_branch() {
 604          $limit = 8;
 605          if ($this->children->count() >= $limit) {
 606              return false;
 607          }
 608          foreach ($this->children as $child) {
 609              if ($child->has_children()) {
 610                  return false;
 611              }
 612          }
 613          return true;
 614      }
 615  
 616      /**
 617       * Finds the active node.
 618       *
 619       * Searches this nodes children plus all of the children for the active node
 620       * and returns it if found.
 621       *
 622       * Recursive.
 623       *
 624       * @return navigation_node|false
 625       */
 626      public function find_active_node() {
 627          if ($this->isactive) {
 628              return $this;
 629          } else {
 630              foreach ($this->children as &$child) {
 631                  $outcome = $child->find_active_node();
 632                  if ($outcome !== false) {
 633                      return $outcome;
 634                  }
 635              }
 636          }
 637          return false;
 638      }
 639  
 640      /**
 641       * Searches all children for the best matching active node
 642       * @return navigation_node|false
 643       */
 644      public function search_for_active_node() {
 645          if ($this->check_if_active(URL_MATCH_BASE)) {
 646              return $this;
 647          } else {
 648              foreach ($this->children as &$child) {
 649                  $outcome = $child->search_for_active_node();
 650                  if ($outcome !== false) {
 651                      return $outcome;
 652                  }
 653              }
 654          }
 655          return false;
 656      }
 657  
 658      /**
 659       * Gets the content for this node.
 660       *
 661       * @param bool $shorttext If true shorttext is used rather than the normal text
 662       * @return string
 663       */
 664      public function get_content($shorttext=false) {
 665          if ($shorttext && $this->shorttext!==null) {
 666              return format_string($this->shorttext);
 667          } else {
 668              return format_string($this->text);
 669          }
 670      }
 671  
 672      /**
 673       * Gets the title to use for this node.
 674       *
 675       * @return string
 676       */
 677      public function get_title() {
 678          if ($this->forcetitle || $this->action != null){
 679              return $this->title;
 680          } else {
 681              return '';
 682          }
 683      }
 684  
 685      /**
 686       * Used to easily determine if this link in the breadcrumbs has a valid action/url.
 687       *
 688       * @return boolean
 689       */
 690      public function has_action() {
 691          return !empty($this->action);
 692      }
 693  
 694      /**
 695       * Used to easily determine if this link in the breadcrumbs is hidden.
 696       *
 697       * @return boolean
 698       */
 699      public function is_hidden() {
 700          return $this->hidden;
 701      }
 702  
 703      /**
 704       * Gets the CSS class to add to this node to describe its type
 705       *
 706       * @return string
 707       */
 708      public function get_css_type() {
 709          if (array_key_exists($this->type, $this->namedtypes)) {
 710              return 'type_'.$this->namedtypes[$this->type];
 711          }
 712          return 'type_unknown';
 713      }
 714  
 715      /**
 716       * Finds all nodes that are expandable by AJAX
 717       *
 718       * @param array $expandable An array by reference to populate with expandable nodes.
 719       */
 720      public function find_expandable(array &$expandable) {
 721          foreach ($this->children as &$child) {
 722              if ($child->display && $child->has_children() && $child->children->count() == 0) {
 723                  $child->id = 'expandable_branch_'.$child->type.'_'.clean_param($child->key, PARAM_ALPHANUMEXT);
 724                  $this->add_class('canexpand');
 725                  $child->requiresajaxloading = true;
 726                  $expandable[] = array('id' => $child->id, 'key' => $child->key, 'type' => $child->type);
 727              }
 728              $child->find_expandable($expandable);
 729          }
 730      }
 731  
 732      /**
 733       * Finds all nodes of a given type (recursive)
 734       *
 735       * @param int $type One of navigation_node::TYPE_*
 736       * @return array
 737       */
 738      public function find_all_of_type($type) {
 739          $nodes = $this->children->type($type);
 740          foreach ($this->children as &$node) {
 741              $childnodes = $node->find_all_of_type($type);
 742              $nodes = array_merge($nodes, $childnodes);
 743          }
 744          return $nodes;
 745      }
 746  
 747      /**
 748       * Removes this node if it is empty
 749       */
 750      public function trim_if_empty() {
 751          if ($this->children->count() == 0) {
 752              $this->remove();
 753          }
 754      }
 755  
 756      /**
 757       * Creates a tab representation of this nodes children that can be used
 758       * with print_tabs to produce the tabs on a page.
 759       *
 760       * call_user_func_array('print_tabs', $node->get_tabs_array());
 761       *
 762       * @param array $inactive
 763       * @param bool $return
 764       * @return array Array (tabs, selected, inactive, activated, return)
 765       */
 766      public function get_tabs_array(array $inactive=array(), $return=false) {
 767          $tabs = array();
 768          $rows = array();
 769          $selected = null;
 770          $activated = array();
 771          foreach ($this->children as $node) {
 772              $tabs[] = new tabobject($node->key, $node->action, $node->get_content(), $node->get_title());
 773              if ($node->contains_active_node()) {
 774                  if ($node->children->count() > 0) {
 775                      $activated[] = $node->key;
 776                      foreach ($node->children as $child) {
 777                          if ($child->contains_active_node()) {
 778                              $selected = $child->key;
 779                          }
 780                          $rows[] = new tabobject($child->key, $child->action, $child->get_content(), $child->get_title());
 781                      }
 782                  } else {
 783                      $selected = $node->key;
 784                  }
 785              }
 786          }
 787          return array(array($tabs, $rows), $selected, $inactive, $activated, $return);
 788      }
 789  
 790      /**
 791       * Sets the parent for this node and if this node is active ensures that the tree is properly
 792       * adjusted as well.
 793       *
 794       * @param navigation_node $parent
 795       */
 796      public function set_parent(navigation_node $parent) {
 797          // Set the parent (thats the easy part)
 798          $this->parent = $parent;
 799          // Check if this node is active (this is checked during construction)
 800          if ($this->isactive) {
 801              // Force all of the parent nodes open so you can see this node
 802              $this->parent->force_open();
 803              // Make all parents inactive so that its clear where we are.
 804              $this->parent->make_inactive();
 805          }
 806      }
 807  
 808      /**
 809       * Hides the node and any children it has.
 810       *
 811       * @since Moodle 2.5
 812       * @param array $typestohide Optional. An array of node types that should be hidden.
 813       *      If null all nodes will be hidden.
 814       *      If an array is given then nodes will only be hidden if their type mtatches an element in the array.
 815       *          e.g. array(navigation_node::TYPE_COURSE) would hide only course nodes.
 816       */
 817      public function hide(array $typestohide = null) {
 818          if ($typestohide === null || in_array($this->type, $typestohide)) {
 819              $this->display = false;
 820              if ($this->has_children()) {
 821                  foreach ($this->children as $child) {
 822                      $child->hide($typestohide);
 823                  }
 824              }
 825          }
 826      }
 827  
 828      /**
 829       * Get the action url for this navigation node.
 830       * Called from templates.
 831       *
 832       * @since Moodle 3.2
 833       */
 834      public function action() {
 835          if ($this->action instanceof moodle_url) {
 836              return $this->action;
 837          } else if ($this->action instanceof action_link) {
 838              return $this->action->url;
 839          }
 840          return $this->action;
 841      }
 842  
 843      /**
 844       * Add the menu item to handle locking and unlocking of a conext.
 845       *
 846       * @param \navigation_node $node Node to add
 847       * @param \context $context The context to be locked
 848       */
 849      protected function add_context_locking_node(\navigation_node $node, \context $context) {
 850          global $CFG;
 851          // Manage context locking.
 852          if (!empty($CFG->contextlocking) && has_capability('moodle/site:managecontextlocks', $context)) {
 853              $parentcontext = $context->get_parent_context();
 854              if (empty($parentcontext) || !$parentcontext->locked) {
 855                  if ($context->locked) {
 856                      $lockicon = 'i/unlock';
 857                      $lockstring = get_string('managecontextunlock', 'admin');
 858                  } else {
 859                      $lockicon = 'i/lock';
 860                      $lockstring = get_string('managecontextlock', 'admin');
 861                  }
 862                  $node->add(
 863                      $lockstring,
 864                      new moodle_url(
 865                          '/admin/lock.php',
 866                          [
 867                              'id' => $context->id,
 868                          ]
 869                      ),
 870                      self::TYPE_SETTING,
 871                      null,
 872                      'contextlocking',
 873                       new pix_icon($lockicon, '')
 874                  );
 875              }
 876          }
 877  
 878      }
 879  }
 880  
 881  /**
 882   * Navigation node collection
 883   *
 884   * This class is responsible for managing a collection of navigation nodes.
 885   * It is required because a node's unique identifier is a combination of both its
 886   * key and its type.
 887   *
 888   * Originally an array was used with a string key that was a combination of the two
 889   * however it was decided that a better solution would be to use a class that
 890   * implements the standard IteratorAggregate interface.
 891   *
 892   * @package   core
 893   * @category  navigation
 894   * @copyright 2010 Sam Hemelryk
 895   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 896   */
 897  class navigation_node_collection implements IteratorAggregate, Countable {
 898      /**
 899       * A multidimensional array to where the first key is the type and the second
 900       * key is the nodes key.
 901       * @var array
 902       */
 903      protected $collection = array();
 904      /**
 905       * An array that contains references to nodes in the same order they were added.
 906       * This is maintained as a progressive array.
 907       * @var array
 908       */
 909      protected $orderedcollection = array();
 910      /**
 911       * A reference to the last node that was added to the collection
 912       * @var navigation_node
 913       */
 914      protected $last = null;
 915      /**
 916       * The total number of items added to this array.
 917       * @var int
 918       */
 919      protected $count = 0;
 920  
 921      /**
 922       * Label for collection of nodes.
 923       * @var string
 924       */
 925      protected $collectionlabel = '';
 926  
 927      /**
 928       * Adds a navigation node to the collection
 929       *
 930       * @param navigation_node $node Node to add
 931       * @param string $beforekey If specified, adds before a node with this key,
 932       *   otherwise adds at end
 933       * @return navigation_node Added node
 934       */
 935      public function add(navigation_node $node, $beforekey=null) {
 936          global $CFG;
 937          $key = $node->key;
 938          $type = $node->type;
 939  
 940          // First check we have a 2nd dimension for this type
 941          if (!array_key_exists($type, $this->orderedcollection)) {
 942              $this->orderedcollection[$type] = array();
 943          }
 944          // Check for a collision and report if debugging is turned on
 945          if ($CFG->debug && array_key_exists($key, $this->orderedcollection[$type])) {
 946              debugging('Navigation node intersect: Adding a node that already exists '.$key, DEBUG_DEVELOPER);
 947          }
 948  
 949          // Find the key to add before
 950          $newindex = $this->count;
 951          $last = true;
 952          if ($beforekey !== null) {
 953              foreach ($this->collection as $index => $othernode) {
 954                  if ($othernode->key === $beforekey) {
 955                      $newindex = $index;
 956                      $last = false;
 957                      break;
 958                  }
 959              }
 960              if ($newindex === $this->count) {
 961                  debugging('Navigation node add_before: Reference node not found ' . $beforekey .
 962                          ', options: ' . implode(' ', $this->get_key_list()), DEBUG_DEVELOPER);
 963              }
 964          }
 965  
 966          // Add the node to the appropriate place in the by-type structure (which
 967          // is not ordered, despite the variable name)
 968          $this->orderedcollection[$type][$key] = $node;
 969          if (!$last) {
 970              // Update existing references in the ordered collection (which is the
 971              // one that isn't called 'ordered') to shuffle them along if required
 972              for ($oldindex = $this->count; $oldindex > $newindex; $oldindex--) {
 973                  $this->collection[$oldindex] = $this->collection[$oldindex - 1];
 974              }
 975          }
 976          // Add a reference to the node to the progressive collection.
 977          $this->collection[$newindex] = $this->orderedcollection[$type][$key];
 978          // Update the last property to a reference to this new node.
 979          $this->last = $this->orderedcollection[$type][$key];
 980  
 981          // Reorder the array by index if needed
 982          if (!$last) {
 983              ksort($this->collection);
 984          }
 985          $this->count++;
 986          // Return the reference to the now added node
 987          return $node;
 988      }
 989  
 990      /**
 991       * Return a list of all the keys of all the nodes.
 992       * @return array the keys.
 993       */
 994      public function get_key_list() {
 995          $keys = array();
 996          foreach ($this->collection as $node) {
 997              $keys[] = $node->key;
 998          }
 999          return $keys;
1000      }
1001  
1002      /**
1003       * Set a label for this collection.
1004       *
1005       * @param string $label
1006       */
1007      public function set_collectionlabel($label) {
1008          $this->collectionlabel = $label;
1009      }
1010  
1011      /**
1012       * Return a label for this collection.
1013       *
1014       * @return string
1015       */
1016      public function get_collectionlabel() {
1017          return $this->collectionlabel;
1018      }
1019  
1020      /**
1021       * Fetches a node from this collection.
1022       *
1023       * @param string|int $key The key of the node we want to find.
1024       * @param int $type One of navigation_node::TYPE_*.
1025       * @return navigation_node|null
1026       */
1027      public function get($key, $type=null) {
1028          if ($type !== null) {
1029              // If the type is known then we can simply check and fetch
1030              if (!empty($this->orderedcollection[$type][$key])) {
1031                  return $this->orderedcollection[$type][$key];
1032              }
1033          } else {
1034              // Because we don't know the type we look in the progressive array
1035              foreach ($this->collection as $node) {
1036                  if ($node->key === $key) {
1037                      return $node;
1038                  }
1039              }
1040          }
1041          return false;
1042      }
1043  
1044      /**
1045       * Searches for a node with matching key and type.
1046       *
1047       * This function searches both the nodes in this collection and all of
1048       * the nodes in each collection belonging to the nodes in this collection.
1049       *
1050       * Recursive.
1051       *
1052       * @param string|int $key  The key of the node we want to find.
1053       * @param int $type  One of navigation_node::TYPE_*.
1054       * @return navigation_node|null
1055       */
1056      public function find($key, $type=null) {
1057          if ($type !== null && array_key_exists($type, $this->orderedcollection) && array_key_exists($key, $this->orderedcollection[$type])) {
1058              return $this->orderedcollection[$type][$key];
1059          } else {
1060              $nodes = $this->getIterator();
1061              // Search immediate children first
1062              foreach ($nodes as &$node) {
1063                  if ($node->key === $key && ($type === null || $type === $node->type)) {
1064                      return $node;
1065                  }
1066              }
1067              // Now search each childs children
1068              foreach ($nodes as &$node) {
1069                  $result = $node->children->find($key, $type);
1070                  if ($result !== false) {
1071                      return $result;
1072                  }
1073              }
1074          }
1075          return false;
1076      }
1077  
1078      /**
1079       * Fetches the last node that was added to this collection
1080       *
1081       * @return navigation_node
1082       */
1083      public function last() {
1084          return $this->last;
1085      }
1086  
1087      /**
1088       * Fetches all nodes of a given type from this collection
1089       *
1090       * @param string|int $type  node type being searched for.
1091       * @return array ordered collection
1092       */
1093      public function type($type) {
1094          if (!array_key_exists($type, $this->orderedcollection)) {
1095              $this->orderedcollection[$type] = array();
1096          }
1097          return $this->orderedcollection[$type];
1098      }
1099      /**
1100       * Removes the node with the given key and type from the collection
1101       *
1102       * @param string|int $key The key of the node we want to find.
1103       * @param int $type
1104       * @return bool
1105       */
1106      public function remove($key, $type=null) {
1107          $child = $this->get($key, $type);
1108          if ($child !== false) {
1109              foreach ($this->collection as $colkey => $node) {
1110                  if ($node->key === $key && (is_null($type) || $node->type == $type)) {
1111                      unset($this->collection[$colkey]);
1112                      $this->collection = array_values($this->collection);
1113                      break;
1114                  }
1115              }
1116              unset($this->orderedcollection[$child->type][$child->key]);
1117              $this->count--;
1118              return true;
1119          }
1120          return false;
1121      }
1122  
1123      /**
1124       * Gets the number of nodes in this collection
1125       *
1126       * This option uses an internal count rather than counting the actual options to avoid
1127       * a performance hit through the count function.
1128       *
1129       * @return int
1130       */
1131      public function count() {
1132          return $this->count;
1133      }
1134      /**
1135       * Gets an array iterator for the collection.
1136       *
1137       * This is required by the IteratorAggregator interface and is used by routines
1138       * such as the foreach loop.
1139       *
1140       * @return ArrayIterator
1141       */
1142      public function getIterator() {
1143          return new ArrayIterator($this->collection);
1144      }
1145  }
1146  
1147  /**
1148   * The global navigation class used for... the global navigation
1149   *
1150   * This class is used by PAGE to store the global navigation for the site
1151   * and is then used by the settings nav and navbar to save on processing and DB calls
1152   *
1153   * See
1154   * {@link lib/pagelib.php} {@link moodle_page::initialise_theme_and_output()}
1155   * {@link lib/ajax/getnavbranch.php} Called by ajax
1156   *
1157   * @package   core
1158   * @category  navigation
1159   * @copyright 2009 Sam Hemelryk
1160   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1161   */
1162  class global_navigation extends navigation_node {
1163      /** @var moodle_page The Moodle page this navigation object belongs to. */
1164      protected $page;
1165      /** @var bool switch to let us know if the navigation object is initialised*/
1166      protected $initialised = false;
1167      /** @var array An array of course information */
1168      protected $mycourses = array();
1169      /** @var navigation_node[] An array for containing  root navigation nodes */
1170      protected $rootnodes = array();
1171      /** @var bool A switch for whether to show empty sections in the navigation */
1172      protected $showemptysections = true;
1173      /** @var bool A switch for whether courses should be shown within categories on the navigation. */
1174      protected $showcategories = null;
1175      /** @var null@var bool A switch for whether or not to show categories in the my courses branch. */
1176      protected $showmycategories = null;
1177      /** @var array An array of stdClasses for users that the navigation is extended for */
1178      protected $extendforuser = array();
1179      /** @var navigation_cache */
1180      protected $cache;
1181      /** @var array An array of course ids that are present in the navigation */
1182      protected $addedcourses = array();
1183      /** @var bool */
1184      protected $allcategoriesloaded = false;
1185      /** @var array An array of category ids that are included in the navigation */
1186      protected $addedcategories = array();
1187      /** @var int expansion limit */
1188      protected $expansionlimit = 0;
1189      /** @var int userid to allow parent to see child's profile page navigation */
1190      protected $useridtouseforparentchecks = 0;
1191      /** @var cache_session A cache that stores information on expanded courses */
1192      protected $cacheexpandcourse = null;
1193  
1194      /** Used when loading categories to load all top level categories [parent = 0] **/
1195      const LOAD_ROOT_CATEGORIES = 0;
1196      /** Used when loading categories to load all categories **/
1197      const LOAD_ALL_CATEGORIES = -1;
1198  
1199      /**
1200       * Constructs a new global navigation
1201       *
1202       * @param moodle_page $page The page this navigation object belongs to
1203       */
1204      public function __construct(moodle_page $page) {
1205          global $CFG, $SITE, $USER;
1206  
1207          if (during_initial_install()) {
1208              return;
1209          }
1210  
1211          if (get_home_page() == HOMEPAGE_SITE) {
1212              // We are using the site home for the root element
1213              $properties = array(
1214                  'key' => 'home',
1215                  'type' => navigation_node::TYPE_SYSTEM,
1216                  'text' => get_string('home'),
1217                  'action' => new moodle_url('/'),
1218                  'icon' => new pix_icon('i/home', '')
1219              );
1220          } else {
1221              // We are using the users my moodle for the root element
1222              $properties = array(
1223                  'key' => 'myhome',
1224                  'type' => navigation_node::TYPE_SYSTEM,
1225                  'text' => get_string('myhome'),
1226                  'action' => new moodle_url('/my/'),
1227                  'icon' => new pix_icon('i/dashboard', '')
1228              );
1229          }
1230  
1231          // Use the parents constructor.... good good reuse
1232          parent::__construct($properties);
1233          $this->showinflatnavigation = true;
1234  
1235          // Initalise and set defaults
1236          $this->page = $page;
1237          $this->forceopen = true;
1238          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
1239      }
1240  
1241      /**
1242       * Mutator to set userid to allow parent to see child's profile
1243       * page navigation. See MDL-25805 for initial issue. Linked to it
1244       * is an issue explaining why this is a REALLY UGLY HACK thats not
1245       * for you to use!
1246       *
1247       * @param int $userid userid of profile page that parent wants to navigate around.
1248       */
1249      public function set_userid_for_parent_checks($userid) {
1250          $this->useridtouseforparentchecks = $userid;
1251      }
1252  
1253  
1254      /**
1255       * Initialises the navigation object.
1256       *
1257       * This causes the navigation object to look at the current state of the page
1258       * that it is associated with and then load the appropriate content.
1259       *
1260       * This should only occur the first time that the navigation structure is utilised
1261       * which will normally be either when the navbar is called to be displayed or
1262       * when a block makes use of it.
1263       *
1264       * @return bool
1265       */
1266      public function initialise() {
1267          global $CFG, $SITE, $USER;
1268          // Check if it has already been initialised
1269          if ($this->initialised || during_initial_install()) {
1270              return true;
1271          }
1272          $this->initialised = true;
1273  
1274          // Set up the five base root nodes. These are nodes where we will put our
1275          // content and are as follows:
1276          // site: Navigation for the front page.
1277          // myprofile: User profile information goes here.
1278          // currentcourse: The course being currently viewed.
1279          // mycourses: The users courses get added here.
1280          // courses: Additional courses are added here.
1281          // users: Other users information loaded here.
1282          $this->rootnodes = array();
1283          if (get_home_page() == HOMEPAGE_SITE) {
1284              // The home element should be my moodle because the root element is the site
1285              if (isloggedin() && !isguestuser()) {  // Makes no sense if you aren't logged in
1286                  $this->rootnodes['home'] = $this->add(get_string('myhome'), new moodle_url('/my/'),
1287                      self::TYPE_SETTING, null, 'myhome', new pix_icon('i/dashboard', ''));
1288                  $this->rootnodes['home']->showinflatnavigation = true;
1289              }
1290          } else {
1291              // The home element should be the site because the root node is my moodle
1292              $this->rootnodes['home'] = $this->add(get_string('sitehome'), new moodle_url('/'),
1293                  self::TYPE_SETTING, null, 'home', new pix_icon('i/home', ''));
1294              $this->rootnodes['home']->showinflatnavigation = true;
1295              if (!empty($CFG->defaulthomepage) && ($CFG->defaulthomepage == HOMEPAGE_MY)) {
1296                  // We need to stop automatic redirection
1297                  $this->rootnodes['home']->action->param('redirect', '0');
1298              }
1299          }
1300          $this->rootnodes['site'] = $this->add_course($SITE);
1301          $this->rootnodes['myprofile'] = $this->add(get_string('profile'), null, self::TYPE_USER, null, 'myprofile');
1302          $this->rootnodes['currentcourse'] = $this->add(get_string('currentcourse'), null, self::TYPE_ROOTNODE, null, 'currentcourse');
1303          $this->rootnodes['mycourses'] = $this->add(get_string('mycourses'), null, self::TYPE_ROOTNODE, null, 'mycourses', new pix_icon('i/course', ''));
1304          $this->rootnodes['courses'] = $this->add(get_string('courses'), new moodle_url('/course/index.php'), self::TYPE_ROOTNODE, null, 'courses');
1305          if (!core_course_category::user_top()) {
1306              $this->rootnodes['courses']->hide();
1307          }
1308          $this->rootnodes['users'] = $this->add(get_string('users'), null, self::TYPE_ROOTNODE, null, 'users');
1309  
1310          // We always load the frontpage course to ensure it is available without
1311          // JavaScript enabled.
1312          $this->add_front_page_course_essentials($this->rootnodes['site'], $SITE);
1313          $this->load_course_sections($SITE, $this->rootnodes['site']);
1314  
1315          $course = $this->page->course;
1316          $this->load_courses_enrolled();
1317  
1318          // $issite gets set to true if the current pages course is the sites frontpage course
1319          $issite = ($this->page->course->id == $SITE->id);
1320  
1321          // Determine if the user is enrolled in any course.
1322          $enrolledinanycourse = enrol_user_sees_own_courses();
1323  
1324          $this->rootnodes['currentcourse']->mainnavonly = true;
1325          if ($enrolledinanycourse) {
1326              $this->rootnodes['mycourses']->isexpandable = true;
1327              $this->rootnodes['mycourses']->showinflatnavigation = true;
1328              if ($CFG->navshowallcourses) {
1329                  // When we show all courses we need to show both the my courses and the regular courses branch.
1330                  $this->rootnodes['courses']->isexpandable = true;
1331              }
1332          } else {
1333              $this->rootnodes['courses']->isexpandable = true;
1334          }
1335          $this->rootnodes['mycourses']->forceopen = true;
1336  
1337          $canviewcourseprofile = true;
1338  
1339          // Next load context specific content into the navigation
1340          switch ($this->page->context->contextlevel) {
1341              case CONTEXT_SYSTEM :
1342                  // Nothing left to do here I feel.
1343                  break;
1344              case CONTEXT_COURSECAT :
1345                  // This is essential, we must load categories.
1346                  $this->load_all_categories($this->page->context->instanceid, true);
1347                  break;
1348              case CONTEXT_BLOCK :
1349              case CONTEXT_COURSE :
1350                  if ($issite) {
1351                      // Nothing left to do here.
1352                      break;
1353                  }
1354  
1355                  // Load the course associated with the current page into the navigation.
1356                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1357                  // If the course wasn't added then don't try going any further.
1358                  if (!$coursenode) {
1359                      $canviewcourseprofile = false;
1360                      break;
1361                  }
1362  
1363                  // If the user is not enrolled then we only want to show the
1364                  // course node and not populate it.
1365  
1366                  // Not enrolled, can't view, and hasn't switched roles
1367                  if (!can_access_course($course, null, '', true)) {
1368                      if ($coursenode->isexpandable === true) {
1369                          // Obviously the situation has changed, update the cache and adjust the node.
1370                          // This occurs if the user access to a course has been revoked (one way or another) after
1371                          // initially logging in for this session.
1372                          $this->get_expand_course_cache()->set($course->id, 1);
1373                          $coursenode->isexpandable = true;
1374                          $coursenode->nodetype = self::NODETYPE_BRANCH;
1375                      }
1376                      // Very ugly hack - do not force "parents" to enrol into course their child is enrolled in,
1377                      // this hack has been propagated from user/view.php to display the navigation node. (MDL-25805)
1378                      if (!$this->current_user_is_parent_role()) {
1379                          $coursenode->make_active();
1380                          $canviewcourseprofile = false;
1381                          break;
1382                      }
1383                  } else if ($coursenode->isexpandable === false) {
1384                      // Obviously the situation has changed, update the cache and adjust the node.
1385                      // This occurs if the user has been granted access to a course (one way or another) after initially
1386                      // logging in for this session.
1387                      $this->get_expand_course_cache()->set($course->id, 1);
1388                      $coursenode->isexpandable = true;
1389                      $coursenode->nodetype = self::NODETYPE_BRANCH;
1390                  }
1391  
1392                  // Add the essentials such as reports etc...
1393                  $this->add_course_essentials($coursenode, $course);
1394                  // Extend course navigation with it's sections/activities
1395                  $this->load_course_sections($course, $coursenode);
1396                  if (!$coursenode->contains_active_node() && !$coursenode->search_for_active_node()) {
1397                      $coursenode->make_active();
1398                  }
1399  
1400                  break;
1401              case CONTEXT_MODULE :
1402                  if ($issite) {
1403                      // If this is the site course then most information will have
1404                      // already been loaded.
1405                      // However we need to check if there is more content that can
1406                      // yet be loaded for the specific module instance.
1407                      $activitynode = $this->rootnodes['site']->find($this->page->cm->id, navigation_node::TYPE_ACTIVITY);
1408                      if ($activitynode) {
1409                          $this->load_activity($this->page->cm, $this->page->course, $activitynode);
1410                      }
1411                      break;
1412                  }
1413  
1414                  $course = $this->page->course;
1415                  $cm = $this->page->cm;
1416  
1417                  // Load the course associated with the page into the navigation
1418                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1419  
1420                  // If the course wasn't added then don't try going any further.
1421                  if (!$coursenode) {
1422                      $canviewcourseprofile = false;
1423                      break;
1424                  }
1425  
1426                  // If the user is not enrolled then we only want to show the
1427                  // course node and not populate it.
1428                  if (!can_access_course($course, null, '', true)) {
1429                      $coursenode->make_active();
1430                      $canviewcourseprofile = false;
1431                      break;
1432                  }
1433  
1434                  $this->add_course_essentials($coursenode, $course);
1435  
1436                  // Load the course sections into the page
1437                  $this->load_course_sections($course, $coursenode, null, $cm);
1438                  $activity = $coursenode->find($cm->id, navigation_node::TYPE_ACTIVITY);
1439                  if (!empty($activity)) {
1440                      // Finally load the cm specific navigaton information
1441                      $this->load_activity($cm, $course, $activity);
1442                      // Check if we have an active ndoe
1443                      if (!$activity->contains_active_node() && !$activity->search_for_active_node()) {
1444                          // And make the activity node active.
1445                          $activity->make_active();
1446                      }
1447                  }
1448                  break;
1449              case CONTEXT_USER :
1450                  if ($issite) {
1451                      // The users profile information etc is already loaded
1452                      // for the front page.
1453                      break;
1454                  }
1455                  $course = $this->page->course;
1456                  // Load the course associated with the user into the navigation
1457                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1458  
1459                  // If the course wasn't added then don't try going any further.
1460                  if (!$coursenode) {
1461                      $canviewcourseprofile = false;
1462                      break;
1463                  }
1464  
1465                  // If the user is not enrolled then we only want to show the
1466                  // course node and not populate it.
1467                  if (!can_access_course($course, null, '', true)) {
1468                      $coursenode->make_active();
1469                      $canviewcourseprofile = false;
1470                      break;
1471                  }
1472                  $this->add_course_essentials($coursenode, $course);
1473                  $this->load_course_sections($course, $coursenode);
1474                  break;
1475          }
1476  
1477          // Load for the current user
1478          $this->load_for_user();
1479          if ($this->page->context->contextlevel >= CONTEXT_COURSE && $this->page->context->instanceid != $SITE->id && $canviewcourseprofile) {
1480              $this->load_for_user(null, true);
1481          }
1482          // Load each extending user into the navigation.
1483          foreach ($this->extendforuser as $user) {
1484              if ($user->id != $USER->id) {
1485                  $this->load_for_user($user);
1486              }
1487          }
1488  
1489          // Give the local plugins a chance to include some navigation if they want.
1490          $this->load_local_plugin_navigation();
1491  
1492          // Remove any empty root nodes
1493          foreach ($this->rootnodes as $node) {
1494              // Dont remove the home node
1495              /** @var navigation_node $node */
1496              if (!in_array($node->key, ['home', 'myhome']) && !$node->has_children() && !$node->isactive) {
1497                  $node->remove();
1498              }
1499          }
1500  
1501          if (!$this->contains_active_node()) {
1502              $this->search_for_active_node();
1503          }
1504  
1505          // If the user is not logged in modify the navigation structure as detailed
1506          // in {@link http://docs.moodle.org/dev/Navigation_2.0_structure}
1507          if (!isloggedin()) {
1508              $activities = clone($this->rootnodes['site']->children);
1509              $this->rootnodes['site']->remove();
1510              $children = clone($this->children);
1511              $this->children = new navigation_node_collection();
1512              foreach ($activities as $child) {
1513                  $this->children->add($child);
1514              }
1515              foreach ($children as $child) {
1516                  $this->children->add($child);
1517              }
1518          }
1519          return true;
1520      }
1521  
1522      /**
1523       * This function gives local plugins an opportunity to modify navigation.
1524       */
1525      protected function load_local_plugin_navigation() {
1526          foreach (get_plugin_list_with_function('local', 'extend_navigation') as $function) {
1527              $function($this);
1528          }
1529      }
1530  
1531      /**
1532       * Returns true if the current user is a parent of the user being currently viewed.
1533       *
1534       * If the current user is not viewing another user, or if the current user does not hold any parent roles over the
1535       * other user being viewed this function returns false.
1536       * In order to set the user for whom we are checking against you must call {@link set_userid_for_parent_checks()}
1537       *
1538       * @since Moodle 2.4
1539       * @return bool
1540       */
1541      protected function current_user_is_parent_role() {
1542          global $USER, $DB;
1543          if ($this->useridtouseforparentchecks && $this->useridtouseforparentchecks != $USER->id) {
1544              $usercontext = context_user::instance($this->useridtouseforparentchecks, MUST_EXIST);
1545              if (!has_capability('moodle/user:viewdetails', $usercontext)) {
1546                  return false;
1547              }
1548              if ($DB->record_exists('role_assignments', array('userid' => $USER->id, 'contextid' => $usercontext->id))) {
1549                  return true;
1550              }
1551          }
1552          return false;
1553      }
1554  
1555      /**
1556       * Returns true if courses should be shown within categories on the navigation.
1557       *
1558       * @param bool $ismycourse Set to true if you are calculating this for a course.
1559       * @return bool
1560       */
1561      protected function show_categories($ismycourse = false) {
1562          global $CFG, $DB;
1563          if ($ismycourse) {
1564              return $this->show_my_categories();
1565          }
1566          if ($this->showcategories === null) {
1567              $show = false;
1568              if ($this->page->context->contextlevel == CONTEXT_COURSECAT) {
1569                  $show = true;
1570              } else if (!empty($CFG->navshowcategories) && $DB->count_records('course_categories') > 1) {
1571                  $show = true;
1572              }
1573              $this->showcategories = $show;
1574          }
1575          return $this->showcategories;
1576      }
1577  
1578      /**
1579       * Returns true if we should show categories in the My Courses branch.
1580       * @return bool
1581       */
1582      protected function show_my_categories() {
1583          global $CFG;
1584          if ($this->showmycategories === null) {
1585              $this->showmycategories = !empty($CFG->navshowmycoursecategories) && !core_course_category::is_simple_site();
1586          }
1587          return $this->showmycategories;
1588      }
1589  
1590      /**
1591       * Loads the courses in Moodle into the navigation.
1592       *
1593       * @global moodle_database $DB
1594       * @param string|array $categoryids An array containing categories to load courses
1595       *                     for, OR null to load courses for all categories.
1596       * @return array An array of navigation_nodes one for each course
1597       */
1598      protected function load_all_courses($categoryids = null) {
1599          global $CFG, $DB, $SITE;
1600  
1601          // Work out the limit of courses.
1602          $limit = 20;
1603          if (!empty($CFG->navcourselimit)) {
1604              $limit = $CFG->navcourselimit;
1605          }
1606  
1607          $toload = (empty($CFG->navshowallcourses))?self::LOAD_ROOT_CATEGORIES:self::LOAD_ALL_CATEGORIES;
1608  
1609          // If we are going to show all courses AND we are showing categories then
1610          // to save us repeated DB calls load all of the categories now
1611          if ($this->show_categories()) {
1612              $this->load_all_categories($toload);
1613          }
1614  
1615          // Will be the return of our efforts
1616          $coursenodes = array();
1617  
1618          // Check if we need to show categories.
1619          if ($this->show_categories()) {
1620              // Hmmm we need to show categories... this is going to be painful.
1621              // We now need to fetch up to $limit courses for each category to
1622              // be displayed.
1623              if ($categoryids !== null) {
1624                  if (!is_array($categoryids)) {
1625                      $categoryids = array($categoryids);
1626                  }
1627                  list($categorywhere, $categoryparams) = $DB->get_in_or_equal($categoryids, SQL_PARAMS_NAMED, 'cc');
1628                  $categorywhere = 'WHERE cc.id '.$categorywhere;
1629              } else if ($toload == self::LOAD_ROOT_CATEGORIES) {
1630                  $categorywhere = 'WHERE cc.depth = 1 OR cc.depth = 2';
1631                  $categoryparams = array();
1632              } else {
1633                  $categorywhere = '';
1634                  $categoryparams = array();
1635              }
1636  
1637              // First up we are going to get the categories that we are going to
1638              // need so that we can determine how best to load the courses from them.
1639              $sql = "SELECT cc.id, COUNT(c.id) AS coursecount
1640                          FROM {course_categories} cc
1641                      LEFT JOIN {course} c ON c.category = cc.id
1642                              {$categorywhere}
1643                      GROUP BY cc.id";
1644              $categories = $DB->get_recordset_sql($sql, $categoryparams);
1645              $fullfetch = array();
1646              $partfetch = array();
1647              foreach ($categories as $category) {
1648                  if (!$this->can_add_more_courses_to_category($category->id)) {
1649                      continue;
1650                  }
1651                  if ($category->coursecount > $limit * 5) {
1652                      $partfetch[] = $category->id;
1653                  } else if ($category->coursecount > 0) {
1654                      $fullfetch[] = $category->id;
1655                  }
1656              }
1657              $categories->close();
1658  
1659              if (count($fullfetch)) {
1660                  // First up fetch all of the courses in categories where we know that we are going to
1661                  // need the majority of courses.
1662                  list($categoryids, $categoryparams) = $DB->get_in_or_equal($fullfetch, SQL_PARAMS_NAMED, 'lcategory');
1663                  $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1664                  $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1665                  $categoryparams['contextlevel'] = CONTEXT_COURSE;
1666                  $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1667                              FROM {course} c
1668                                  $ccjoin
1669                              WHERE c.category {$categoryids}
1670                          ORDER BY c.sortorder ASC";
1671                  $coursesrs = $DB->get_recordset_sql($sql, $categoryparams);
1672                  foreach ($coursesrs as $course) {
1673                      if ($course->id == $SITE->id) {
1674                          // This should not be necessary, frontpage is not in any category.
1675                          continue;
1676                      }
1677                      if (array_key_exists($course->id, $this->addedcourses)) {
1678                          // It is probably better to not include the already loaded courses
1679                          // directly in SQL because inequalities may confuse query optimisers
1680                          // and may interfere with query caching.
1681                          continue;
1682                      }
1683                      if (!$this->can_add_more_courses_to_category($course->category)) {
1684                          continue;
1685                      }
1686                      context_helper::preload_from_record($course);
1687                      if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1688                          continue;
1689                      }
1690                      $coursenodes[$course->id] = $this->add_course($course);
1691                  }
1692                  $coursesrs->close();
1693              }
1694  
1695              if (count($partfetch)) {
1696                  // Next we will work our way through the categories where we will likely only need a small
1697                  // proportion of the courses.
1698                  foreach ($partfetch as $categoryid) {
1699                      $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1700                      $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1701                      $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1702                                  FROM {course} c
1703                                      $ccjoin
1704                                  WHERE c.category = :categoryid
1705                              ORDER BY c.sortorder ASC";
1706                      $courseparams = array('categoryid' => $categoryid, 'contextlevel' => CONTEXT_COURSE);
1707                      $coursesrs = $DB->get_recordset_sql($sql, $courseparams, 0, $limit * 5);
1708                      foreach ($coursesrs as $course) {
1709                          if ($course->id == $SITE->id) {
1710                              // This should not be necessary, frontpage is not in any category.
1711                              continue;
1712                          }
1713                          if (array_key_exists($course->id, $this->addedcourses)) {
1714                              // It is probably better to not include the already loaded courses
1715                              // directly in SQL because inequalities may confuse query optimisers
1716                              // and may interfere with query caching.
1717                              // This also helps to respect expected $limit on repeated executions.
1718                              continue;
1719                          }
1720                          if (!$this->can_add_more_courses_to_category($course->category)) {
1721                              break;
1722                          }
1723                          context_helper::preload_from_record($course);
1724                          if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1725                              continue;
1726                          }
1727                          $coursenodes[$course->id] = $this->add_course($course);
1728                      }
1729                      $coursesrs->close();
1730                  }
1731              }
1732          } else {
1733              // Prepare the SQL to load the courses and their contexts
1734              list($courseids, $courseparams) = $DB->get_in_or_equal(array_keys($this->addedcourses), SQL_PARAMS_NAMED, 'lc', false);
1735              $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1736              $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1737              $courseparams['contextlevel'] = CONTEXT_COURSE;
1738              $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1739                          FROM {course} c
1740                              $ccjoin
1741                          WHERE c.id {$courseids}
1742                      ORDER BY c.sortorder ASC";
1743              $coursesrs = $DB->get_recordset_sql($sql, $courseparams);
1744              foreach ($coursesrs as $course) {
1745                  if ($course->id == $SITE->id) {
1746                      // frotpage is not wanted here
1747                      continue;
1748                  }
1749                  if ($this->page->course && ($this->page->course->id == $course->id)) {
1750                      // Don't include the currentcourse in this nodelist - it's displayed in the Current course node
1751                      continue;
1752                  }
1753                  context_helper::preload_from_record($course);
1754                  if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1755                      continue;
1756                  }
1757                  $coursenodes[$course->id] = $this->add_course($course);
1758                  if (count($coursenodes) >= $limit) {
1759                      break;
1760                  }
1761              }
1762              $coursesrs->close();
1763          }
1764  
1765          return $coursenodes;
1766      }
1767  
1768      /**
1769       * Returns true if more courses can be added to the provided category.
1770       *
1771       * @param int|navigation_node|stdClass $category
1772       * @return bool
1773       */
1774      protected function can_add_more_courses_to_category($category) {
1775          global $CFG;
1776          $limit = 20;
1777          if (!empty($CFG->navcourselimit)) {
1778              $limit = (int)$CFG->navcourselimit;
1779          }
1780          if (is_numeric($category)) {
1781              if (!array_key_exists($category, $this->addedcategories)) {
1782                  return true;
1783              }
1784              $coursecount = count($this->addedcategories[$category]->children->type(self::TYPE_COURSE));
1785          } else if ($category instanceof navigation_node) {
1786              if (($category->type != self::TYPE_CATEGORY) || ($category->type != self::TYPE_MY_CATEGORY)) {
1787                  return false;
1788              }
1789              $coursecount = count($category->children->type(self::TYPE_COURSE));
1790          } else if (is_object($category) && property_exists($category,'id')) {
1791              $coursecount = count($this->addedcategories[$category->id]->children->type(self::TYPE_COURSE));
1792          }
1793          return ($coursecount <= $limit);
1794      }
1795  
1796      /**
1797       * Loads all categories (top level or if an id is specified for that category)
1798       *
1799       * @param int $categoryid The category id to load or null/0 to load all base level categories
1800       * @param bool $showbasecategories If set to true all base level categories will be loaded as well
1801       *        as the requested category and any parent categories.
1802       * @return navigation_node|void returns a navigation node if a category has been loaded.
1803       */
1804      protected function load_all_categories($categoryid = self::LOAD_ROOT_CATEGORIES, $showbasecategories = false) {
1805          global $CFG, $DB;
1806  
1807          // Check if this category has already been loaded
1808          if ($this->allcategoriesloaded || ($categoryid < 1 && $this->is_category_fully_loaded($categoryid))) {
1809              return true;
1810          }
1811  
1812          $catcontextsql = context_helper::get_preload_record_columns_sql('ctx');
1813          $sqlselect = "SELECT cc.*, $catcontextsql
1814                        FROM {course_categories} cc
1815                        JOIN {context} ctx ON cc.id = ctx.instanceid";
1816          $sqlwhere = "WHERE ctx.contextlevel = ".CONTEXT_COURSECAT;
1817          $sqlorder = "ORDER BY cc.depth ASC, cc.sortorder ASC, cc.id ASC";
1818          $params = array();
1819  
1820          $categoriestoload = array();
1821          if ($categoryid == self::LOAD_ALL_CATEGORIES) {
1822              // We are going to load all categories regardless... prepare to fire
1823              // on the database server!
1824          } else if ($categoryid == self::LOAD_ROOT_CATEGORIES) { // can be 0
1825              // We are going to load all of the first level categories (categories without parents)
1826              $sqlwhere .= " AND cc.parent = 0";
1827          } else if (array_key_exists($categoryid, $this->addedcategories)) {
1828              // The category itself has been loaded already so we just need to ensure its subcategories
1829              // have been loaded
1830              $addedcategories = $this->addedcategories;
1831              unset($addedcategories[$categoryid]);
1832              if (count($addedcategories) > 0) {
1833                  list($sql, $params) = $DB->get_in_or_equal(array_keys($addedcategories), SQL_PARAMS_NAMED, 'parent', false);
1834                  if ($showbasecategories) {
1835                      // We need to include categories with parent = 0 as well
1836                      $sqlwhere .= " AND (cc.parent = :categoryid OR cc.parent = 0) AND cc.parent {$sql}";
1837                  } else {
1838                      // All we need is categories that match the parent
1839                      $sqlwhere .= " AND cc.parent = :categoryid AND cc.parent {$sql}";
1840                  }
1841              }
1842              $params['categoryid'] = $categoryid;
1843          } else {
1844              // This category hasn't been loaded yet so we need to fetch it, work out its category path
1845              // and load this category plus all its parents and subcategories
1846              $category = $DB->get_record('course_categories', array('id' => $categoryid), 'path', MUST_EXIST);
1847              $categoriestoload = explode('/', trim($category->path, '/'));
1848              list($select, $params) = $DB->get_in_or_equal($categoriestoload);
1849              // We are going to use select twice so double the params
1850              $params = array_merge($params, $params);
1851              $basecategorysql = ($showbasecategories)?' OR cc.depth = 1':'';
1852              $sqlwhere .= " AND (cc.id {$select} OR cc.parent {$select}{$basecategorysql})";
1853          }
1854  
1855          $categoriesrs = $DB->get_recordset_sql("$sqlselect $sqlwhere $sqlorder", $params);
1856          $categories = array();
1857          foreach ($categoriesrs as $category) {
1858              // Preload the context.. we'll need it when adding the category in order
1859              // to format the category name.
1860              context_helper::preload_from_record($category);
1861              if (array_key_exists($category->id, $this->addedcategories)) {
1862                  // Do nothing, its already been added.
1863              } else if ($category->parent == '0') {
1864                  // This is a root category lets add it immediately
1865                  $this->add_category($category, $this->rootnodes['courses']);
1866              } else if (array_key_exists($category->parent, $this->addedcategories)) {
1867                  // This categories parent has already been added we can add this immediately
1868                  $this->add_category($category, $this->addedcategories[$category->parent]);
1869              } else {
1870                  $categories[] = $category;
1871              }
1872          }
1873          $categoriesrs->close();
1874  
1875          // Now we have an array of categories we need to add them to the navigation.
1876          while (!empty($categories)) {
1877              $category = reset($categories);
1878              if (array_key_exists($category->id, $this->addedcategories)) {
1879                  // Do nothing
1880              } else if ($category->parent == '0') {
1881                  $this->add_category($category, $this->rootnodes['courses']);
1882              } else if (array_key_exists($category->parent, $this->addedcategories)) {
1883                  $this->add_category($category, $this->addedcategories[$category->parent]);
1884              } else {
1885                  // This category isn't in the navigation and niether is it's parent (yet).
1886                  // We need to go through the category path and add all of its components in order.
1887                  $path = explode('/', trim($category->path, '/'));
1888                  foreach ($path as $catid) {
1889                      if (!array_key_exists($catid, $this->addedcategories)) {
1890                          // This category isn't in the navigation yet so add it.
1891                          $subcategory = $categories[$catid];
1892                          if ($subcategory->parent == '0') {
1893                              // Yay we have a root category - this likely means we will now be able
1894                              // to add categories without problems.
1895                              $this->add_category($subcategory, $this->rootnodes['courses']);
1896                          } else if (array_key_exists($subcategory->parent, $this->addedcategories)) {
1897                              // The parent is in the category (as we'd expect) so add it now.
1898                              $this->add_category($subcategory, $this->addedcategories[$subcategory->parent]);
1899                              // Remove the category from the categories array.
1900                              unset($categories[$catid]);
1901                          } else {
1902                              // We should never ever arrive here - if we have then there is a bigger
1903                              // problem at hand.
1904                              throw new coding_exception('Category path order is incorrect and/or there are missing categories');
1905                          }
1906                      }
1907                  }
1908              }
1909              // Remove the category from the categories array now that we know it has been added.
1910              unset($categories[$category->id]);
1911          }
1912          if ($categoryid === self::LOAD_ALL_CATEGORIES) {
1913              $this->allcategoriesloaded = true;
1914          }
1915          // Check if there are any categories to load.
1916          if (count($categoriestoload) > 0) {
1917              $readytoloadcourses = array();
1918              foreach ($categoriestoload as $category) {
1919                  if ($this->can_add_more_courses_to_category($category)) {
1920                      $readytoloadcourses[] = $category;
1921                  }
1922              }
1923              if (count($readytoloadcourses)) {
1924                  $this->load_all_courses($readytoloadcourses);
1925              }
1926          }
1927  
1928          // Look for all categories which have been loaded
1929          if (!empty($this->addedcategories)) {
1930              $categoryids = array();
1931              foreach ($this->addedcategories as $category) {
1932                  if ($this->can_add_more_courses_to_category($category)) {
1933                      $categoryids[] = $category->key;
1934                  }
1935              }
1936              if ($categoryids) {
1937                  list($categoriessql, $params) = $DB->get_in_or_equal($categoryids, SQL_PARAMS_NAMED);
1938                  $params['limit'] = (!empty($CFG->navcourselimit))?$CFG->navcourselimit:20;
1939                  $sql = "SELECT cc.id, COUNT(c.id) AS coursecount
1940                            FROM {course_categories} cc
1941                            JOIN {course} c ON c.category = cc.id
1942                           WHERE cc.id {$categoriessql}
1943                        GROUP BY cc.id
1944                          HAVING COUNT(c.id) > :limit";
1945                  $excessivecategories = $DB->get_records_sql($sql, $params);
1946                  foreach ($categories as &$category) {
1947                      if (array_key_exists($category->key, $excessivecategories) && !$this->can_add_more_courses_to_category($category)) {
1948                          $url = new moodle_url('/course/index.php', array('categoryid' => $category->key));
1949                          $category->add(get_string('viewallcourses'), $url, self::TYPE_SETTING);
1950                      }
1951                  }
1952              }
1953          }
1954      }
1955  
1956      /**
1957       * Adds a structured category to the navigation in the correct order/place
1958       *
1959       * @param stdClass $category category to be added in navigation.
1960       * @param navigation_node $parent parent navigation node
1961       * @param int $nodetype type of node, if category is under MyHome then it's TYPE_MY_CATEGORY
1962       * @return void.
1963       */
1964      protected function add_category(stdClass $category, navigation_node $parent, $nodetype = self::TYPE_CATEGORY) {
1965          if (array_key_exists($category->id, $this->addedcategories)) {
1966              return;
1967          }
1968          $canview = core_course_category::can_view_category($category);
1969          $url = $canview ? new moodle_url('/course/index.php', array('categoryid' => $category->id)) : null;
1970          $context = context_coursecat::instance($category->id);
1971          $categoryname = $canview ? format_string($category->name, true, array('context' => $context)) :
1972              get_string('categoryhidden');
1973          $categorynode = $parent->add($categoryname, $url, $nodetype, $categoryname, $category->id);
1974          if (!$canview) {
1975              // User does not have required capabilities to view category.
1976              $categorynode->display = false;
1977          } else if (!$category->visible) {
1978              // Category is hidden but user has capability to view hidden categories.
1979              $categorynode->hidden = true;
1980          }
1981          $this->addedcategories[$category->id] = $categorynode;
1982      }
1983  
1984      /**
1985       * Loads the given course into the navigation
1986       *
1987       * @param stdClass $course
1988       * @return navigation_node
1989       */
1990      protected function load_course(stdClass $course) {
1991          global $SITE;
1992          if ($course->id == $SITE->id) {
1993              // This is always loaded during initialisation
1994              return $this->rootnodes['site'];
1995          } else if (array_key_exists($course->id, $this->addedcourses)) {
1996              // The course has already been loaded so return a reference
1997              return $this->addedcourses[$course->id];
1998          } else {
1999              // Add the course
2000              return $this->add_course($course);
2001          }
2002      }
2003  
2004      /**
2005       * Loads all of the courses section into the navigation.
2006       *
2007       * This function calls method from current course format, see
2008       * {@link format_base::extend_course_navigation()}
2009       * If course module ($cm) is specified but course format failed to create the node,
2010       * the activity node is created anyway.
2011       *
2012       * By default course formats call the method {@link global_navigation::load_generic_course_sections()}
2013       *
2014       * @param stdClass $course Database record for the course
2015       * @param navigation_node $coursenode The course node within the navigation
2016       * @param null|int $sectionnum If specified load the contents of section with this relative number
2017       * @param null|cm_info $cm If specified make sure that activity node is created (either
2018       *    in containg section or by calling load_stealth_activity() )
2019       */
2020      protected function load_course_sections(stdClass $course, navigation_node $coursenode, $sectionnum = null, $cm = null) {
2021          global $CFG, $SITE;
2022          require_once($CFG->dirroot.'/course/lib.php');
2023          if (isset($cm->sectionnum)) {
2024              $sectionnum = $cm->sectionnum;
2025          }
2026          if ($sectionnum !== null) {
2027              $this->includesectionnum = $sectionnum;
2028          }
2029          course_get_format($course)->extend_course_navigation($this, $coursenode, $sectionnum, $cm);
2030          if (isset($cm->id)) {
2031              $activity = $coursenode->find($cm->id, self::TYPE_ACTIVITY);
2032              if (empty($activity)) {
2033                  $activity = $this->load_stealth_activity($coursenode, get_fast_modinfo($course));
2034              }
2035          }
2036     }
2037  
2038      /**
2039       * Generates an array of sections and an array of activities for the given course.
2040       *
2041       * This method uses the cache to improve performance and avoid the get_fast_modinfo call
2042       *
2043       * @param stdClass $course
2044       * @return array Array($sections, $activities)
2045       */
2046      protected function generate_sections_and_activities(stdClass $course) {
2047          global $CFG;
2048          require_once($CFG->dirroot.'/course/lib.php');
2049  
2050          $modinfo = get_fast_modinfo($course);
2051          $sections = $modinfo->get_section_info_all();
2052  
2053          // For course formats using 'numsections' trim the sections list
2054          $courseformatoptions = course_get_format($course)->get_format_options();
2055          if (isset($courseformatoptions['numsections'])) {
2056              $sections = array_slice($sections, 0, $courseformatoptions['numsections']+1, true);
2057          }
2058  
2059          $activities = array();
2060  
2061          foreach ($sections as $key => $section) {
2062              // Clone and unset summary to prevent $SESSION bloat (MDL-31802).
2063              $sections[$key] = clone($section);
2064              unset($sections[$key]->summary);
2065              $sections[$key]->hasactivites = false;
2066              if (!array_key_exists($section->section, $modinfo->sections)) {
2067                  continue;
2068              }
2069              foreach ($modinfo->sections[$section->section] as $cmid) {
2070                  $cm = $modinfo->cms[$cmid];
2071                  $activity = new stdClass;
2072                  $activity->id = $cm->id;
2073                  $activity->course = $course->id;
2074                  $activity->section = $section->section;
2075                  $activity->name = $cm->name;
2076                  $activity->icon = $cm->icon;
2077                  $activity->iconcomponent = $cm->iconcomponent;
2078                  $activity->hidden = (!$cm->visible);
2079                  $activity->modname = $cm->modname;
2080                  $activity->nodetype = navigation_node::NODETYPE_LEAF;
2081                  $activity->onclick = $cm->onclick;
2082                  $url = $cm->url;
2083                  if (!$url) {
2084                      $activity->url = null;
2085                      $activity->display = false;
2086                  } else {
2087                      $activity->url = $url->out();
2088                      $activity->display = $cm->is_visible_on_course_page() ? true : false;
2089                      if (self::module_extends_navigation($cm->modname)) {
2090                          $activity->nodetype = navigation_node::NODETYPE_BRANCH;
2091                      }
2092                  }
2093                  $activities[$cmid] = $activity;
2094                  if ($activity->display) {
2095                      $sections[$key]->hasactivites = true;
2096                  }
2097              }
2098          }
2099  
2100          return array($sections, $activities);
2101      }
2102  
2103      /**
2104       * Generically loads the course sections into the course's navigation.
2105       *
2106       * @param stdClass $course
2107       * @param navigation_node $coursenode
2108       * @return array An array of course section nodes
2109       */
2110      public function load_generic_course_sections(stdClass $course, navigation_node $coursenode) {
2111          global $CFG, $DB, $USER, $SITE;
2112          require_once($CFG->dirroot.'/course/lib.php');
2113  
2114          list($sections, $activities) = $this->generate_sections_and_activities($course);
2115  
2116          $navigationsections = array();
2117          foreach ($sections as $sectionid => $section) {
2118              $section = clone($section);
2119              if ($course->id == $SITE->id) {
2120                  $this->load_section_activities($coursenode, $section->section, $activities);
2121              } else {
2122                  if (!$section->uservisible || (!$this->showemptysections &&
2123                          !$section->hasactivites && $this->includesectionnum !== $section->section)) {
2124                      continue;
2125                  }
2126  
2127                  $sectionname = get_section_name($course, $section);
2128                  $url = course_get_url($course, $section->section, array('navigation' => true));
2129  
2130                  $sectionnode = $coursenode->add($sectionname, $url, navigation_node::TYPE_SECTION,
2131                      null, $section->id, new pix_icon('i/section', ''));
2132                  $sectionnode->nodetype = navigation_node::NODETYPE_BRANCH;
2133                  $sectionnode->hidden = (!$section->visible || !$section->available);
2134                  if ($this->includesectionnum !== false && $this->includesectionnum == $section->section) {
2135                      $this->load_section_activities($sectionnode, $section->section, $activities);
2136                  }
2137                  $section->sectionnode = $sectionnode;
2138                  $navigationsections[$sectionid] = $section;
2139              }
2140          }
2141          return $navigationsections;
2142      }
2143  
2144      /**
2145       * Loads all of the activities for a section into the navigation structure.
2146       *
2147       * @param navigation_node $sectionnode
2148       * @param int $sectionnumber
2149       * @param array $activities An array of activites as returned by {@link global_navigation::generate_sections_and_activities()}
2150       * @param stdClass $course The course object the section and activities relate to.
2151       * @return array Array of activity nodes
2152       */
2153      protected function load_section_activities(navigation_node $sectionnode, $sectionnumber, array $activities, $course = null) {
2154          global $CFG, $SITE;
2155          // A static counter for JS function naming
2156          static $legacyonclickcounter = 0;
2157  
2158          $activitynodes = array();
2159          if (empty($activities)) {
2160              return $activitynodes;
2161          }
2162  
2163          if (!is_object($course)) {
2164              $activity = reset($activities);
2165              $courseid = $activity->course;
2166          } else {
2167              $courseid = $course->id;
2168          }
2169          $showactivities = ($courseid != $SITE->id || !empty($CFG->navshowfrontpagemods));
2170  
2171          foreach ($activities as $activity) {
2172              if ($activity->section != $sectionnumber) {
2173                  continue;
2174              }
2175              if ($activity->icon) {
2176                  $icon = new pix_icon($activity->icon, get_string('modulename', $activity->modname), $activity->iconcomponent);
2177              } else {
2178                  $icon = new pix_icon('icon', get_string('modulename', $activity->modname), $activity->modname);
2179              }
2180  
2181              // Prepare the default name and url for the node
2182              $activityname = format_string($activity->name, true, array('context' => context_module::instance($activity->id)));
2183              $action = new moodle_url($activity->url);
2184  
2185              // Check if the onclick property is set (puke!)
2186              if (!empty($activity->onclick)) {
2187                  // Increment the counter so that we have a unique number.
2188                  $legacyonclickcounter++;
2189                  // Generate the function name we will use
2190                  $functionname = 'legacy_activity_onclick_handler_'.$legacyonclickcounter;
2191                  $propogrationhandler = '';
2192                  // Check if we need to cancel propogation. Remember inline onclick
2193                  // events would return false if they wanted to prevent propogation and the
2194                  // default action.
2195                  if (strpos($activity->onclick, 'return false')) {
2196                      $propogrationhandler = 'e.halt();';
2197                  }
2198                  // Decode the onclick - it has already been encoded for display (puke)
2199                  $onclick = htmlspecialchars_decode($activity->onclick, ENT_QUOTES);
2200                  // Build the JS function the click event will call
2201                  $jscode = "function {$functionname}(e) { $propogrationhandler $onclick }";
2202                  $this->page->requires->js_amd_inline($jscode);
2203                  // Override the default url with the new action link
2204                  $action = new action_link($action, $activityname, new component_action('click', $functionname));
2205              }
2206  
2207              $activitynode = $sectionnode->add($activityname, $action, navigation_node::TYPE_ACTIVITY, null, $activity->id, $icon);
2208              $activitynode->title(get_string('modulename', $activity->modname));
2209              $activitynode->hidden = $activity->hidden;
2210              $activitynode->display = $showactivities && $activity->display;
2211              $activitynode->nodetype = $activity->nodetype;
2212              $activitynodes[$activity->id] = $activitynode;
2213          }
2214  
2215          return $activitynodes;
2216      }
2217      /**
2218       * Loads a stealth module from unavailable section
2219       * @param navigation_node $coursenode
2220       * @param stdClass $modinfo
2221       * @return navigation_node or null if not accessible
2222       */
2223      protected function load_stealth_activity(navigation_node $coursenode, $modinfo) {
2224          if (empty($modinfo->cms[$this->page->cm->id])) {
2225              return null;
2226          }
2227          $cm = $modinfo->cms[$this->page->cm->id];
2228          if ($cm->icon) {
2229              $icon = new pix_icon($cm->icon, get_string('modulename', $cm->modname), $cm->iconcomponent);
2230          } else {
2231              $icon = new pix_icon('icon', get_string('modulename', $cm->modname), $cm->modname);
2232          }
2233          $url = $cm->url;
2234          $activitynode = $coursenode->add(format_string($cm->name), $url, navigation_node::TYPE_ACTIVITY, null, $cm->id, $icon);
2235          $activitynode->title(get_string('modulename', $cm->modname));
2236          $activitynode->hidden = (!$cm->visible);
2237          if (!$cm->is_visible_on_course_page()) {
2238              // Do not show any error here, let the page handle exception that activity is not visible for the current user.
2239              // Also there may be no exception at all in case when teacher is logged in as student.
2240              $activitynode->display = false;
2241          } else if (!$url) {
2242              // Don't show activities that don't have links!
2243              $activitynode->display = false;
2244          } else if (self::module_extends_navigation($cm->modname)) {
2245              $activitynode->nodetype = navigation_node::NODETYPE_BRANCH;
2246          }
2247          return $activitynode;
2248      }
2249      /**
2250       * Loads the navigation structure for the given activity into the activities node.
2251       *
2252       * This method utilises a callback within the modules lib.php file to load the
2253       * content specific to activity given.
2254       *
2255       * The callback is a method: {modulename}_extend_navigation()
2256       * Examples:
2257       *  * {@link forum_extend_navigation()}
2258       *  * {@link workshop_extend_navigation()}
2259       *
2260       * @param cm_info|stdClass $cm
2261       * @param stdClass $course
2262       * @param navigation_node $activity
2263       * @return bool
2264       */
2265      protected function load_activity($cm, stdClass $course, navigation_node $activity) {
2266          global $CFG, $DB;
2267  
2268          // make sure we have a $cm from get_fast_modinfo as this contains activity access details
2269          if (!($cm instanceof cm_info)) {
2270              $modinfo = get_fast_modinfo($course);
2271              $cm = $modinfo->get_cm($cm->id);
2272          }
2273          $activity->nodetype = navigation_node::NODETYPE_LEAF;
2274          $activity->make_active();
2275          $file = $CFG->dirroot.'/mod/'.$cm->modname.'/lib.php';
2276          $function = $cm->modname.'_extend_navigation';
2277  
2278          if (file_exists($file)) {
2279              require_once($file);
2280              if (function_exists($function)) {
2281                  $activtyrecord = $DB->get_record($cm->modname, array('id' => $cm->instance), '*', MUST_EXIST);
2282                  $function($activity, $course, $activtyrecord, $cm);
2283              }
2284          }
2285  
2286          // Allow the active advanced grading method plugin to append module navigation
2287          $featuresfunc = $cm->modname.'_supports';
2288          if (function_exists($featuresfunc) && $featuresfunc(FEATURE_ADVANCED_GRADING)) {
2289              require_once($CFG->dirroot.'/grade/grading/lib.php');
2290              $gradingman = get_grading_manager($cm->context,  'mod_'.$cm->modname);
2291              $gradingman->extend_navigation($this, $activity);
2292          }
2293  
2294          return $activity->has_children();
2295      }
2296      /**
2297       * Loads user specific information into the navigation in the appropriate place.
2298       *
2299       * If no user is provided the current user is assumed.
2300       *
2301       * @param stdClass $user
2302       * @param bool $forceforcontext probably force something to be loaded somewhere (ask SamH if not sure what this means)
2303       * @return bool
2304       */
2305      protected function load_for_user($user=null, $forceforcontext=false) {
2306          global $DB, $CFG, $USER, $SITE;
2307  
2308          require_once($CFG->dirroot . '/course/lib.php');
2309  
2310          if ($user === null) {
2311              // We can't require login here but if the user isn't logged in we don't
2312              // want to show anything
2313              if (!isloggedin() || isguestuser()) {
2314                  return false;
2315              }
2316              $user = $USER;
2317          } else if (!is_object($user)) {
2318              // If the user is not an object then get them from the database
2319              $select = context_helper::get_preload_record_columns_sql('ctx');
2320              $sql = "SELECT u.*, $select
2321                        FROM {user} u
2322                        JOIN {context} ctx ON u.id = ctx.instanceid
2323                       WHERE u.id = :userid AND
2324                             ctx.contextlevel = :contextlevel";
2325              $user = $DB->get_record_sql($sql, array('userid' => (int)$user, 'contextlevel' => CONTEXT_USER), MUST_EXIST);
2326              context_helper::preload_from_record($user);
2327          }
2328  
2329          $iscurrentuser = ($user->id == $USER->id);
2330  
2331          $usercontext = context_user::instance($user->id);
2332  
2333          // Get the course set against the page, by default this will be the site
2334          $course = $this->page->course;
2335          $baseargs = array('id'=>$user->id);
2336          if ($course->id != $SITE->id && (!$iscurrentuser || $forceforcontext)) {
2337              $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
2338              $baseargs['course'] = $course->id;
2339              $coursecontext = context_course::instance($course->id);
2340              $issitecourse = false;
2341          } else {
2342              // Load all categories and get the context for the system
2343              $coursecontext = context_system::instance();
2344              $issitecourse = true;
2345          }
2346  
2347          // Create a node to add user information under.
2348          $usersnode = null;
2349          if (!$issitecourse) {
2350              // Not the current user so add it to the participants node for the current course.
2351              $usersnode = $coursenode->get('participants', navigation_node::TYPE_CONTAINER);
2352              $userviewurl = new moodle_url('/user/view.php', $baseargs);
2353          } else if ($USER->id != $user->id) {
2354              // This is the site so add a users node to the root branch.
2355              $usersnode = $this->rootnodes['users'];
2356              if (course_can_view_participants($coursecontext)) {
2357                  $usersnode->action = new moodle_url('/user/index.php', array('id' => $course->id));
2358              }
2359              $userviewurl = new moodle_url('/user/profile.php', $baseargs);
2360          }
2361          if (!$usersnode) {
2362              // We should NEVER get here, if the course hasn't been populated
2363              // with a participants node then the navigaiton either wasn't generated
2364              // for it (you are missing a require_login or set_context call) or
2365              // you don't have access.... in the interests of no leaking informatin
2366              // we simply quit...
2367              return false;
2368          }
2369          // Add a branch for the current user.
2370          // Only reveal user details if $user is the current user, or a user to which the current user has access.
2371          $viewprofile = true;
2372          if (!$iscurrentuser) {
2373              require_once($CFG->dirroot . '/user/lib.php');
2374              if ($this->page->context->contextlevel == CONTEXT_USER && !has_capability('moodle/user:viewdetails', $usercontext) ) {
2375                  $viewprofile = false;
2376              } else if ($this->page->context->contextlevel != CONTEXT_USER && !user_can_view_profile($user, $course, $usercontext)) {
2377                  $viewprofile = false;
2378              }
2379              if (!$viewprofile) {
2380                  $viewprofile = user_can_view_profile($user, null, $usercontext);
2381              }
2382          }
2383  
2384          // Now, conditionally add the user node.
2385          if ($viewprofile) {
2386              $canseefullname = has_capability('moodle/site:viewfullnames', $coursecontext);
2387              $usernode = $usersnode->add(fullname($user, $canseefullname), $userviewurl, self::TYPE_USER, null, 'user' . $user->id);
2388          } else {
2389              $usernode = $usersnode->add(get_string('user'));
2390          }
2391  
2392          if ($this->page->context->contextlevel == CONTEXT_USER && $user->id == $this->page->context->instanceid) {
2393              $usernode->make_active();
2394          }
2395  
2396          // Add user information to the participants or user node.
2397          if ($issitecourse) {
2398  
2399              // If the user is the current user or has permission to view the details of the requested
2400              // user than add a view profile link.
2401              if ($iscurrentuser || has_capability('moodle/user:viewdetails', $coursecontext) ||
2402                      has_capability('moodle/user:viewdetails', $usercontext)) {
2403                  if ($issitecourse || ($iscurrentuser && !$forceforcontext)) {
2404                      $usernode->add(get_string('viewprofile'), new moodle_url('/user/profile.php', $baseargs));
2405                  } else {
2406                      $usernode->add(get_string('viewprofile'), new moodle_url('/user/view.php', $baseargs));
2407                  }
2408              }
2409  
2410              if (!empty($CFG->navadduserpostslinks)) {
2411                  // Add nodes for forum posts and discussions if the user can view either or both
2412                  // There are no capability checks here as the content of the page is based
2413                  // purely on the forums the current user has access too.
2414                  $forumtab = $usernode->add(get_string('forumposts', 'forum'));
2415                  $forumtab->add(get_string('posts', 'forum'), new moodle_url('/mod/forum/user.php', $baseargs));
2416                  $forumtab->add(get_string('discussions', 'forum'), new moodle_url('/mod/forum/user.php',
2417                          array_merge($baseargs, array('mode' => 'discussions'))));
2418              }
2419  
2420              // Add blog nodes.
2421              if (!empty($CFG->enableblogs)) {
2422                  if (!$this->cache->cached('userblogoptions'.$user->id)) {
2423                      require_once($CFG->dirroot.'/blog/lib.php');
2424                      // Get all options for the user.
2425                      $options = blog_get_options_for_user($user);
2426                      $this->cache->set('userblogoptions'.$user->id, $options);
2427                  } else {
2428                      $options = $this->cache->{'userblogoptions'.$user->id};
2429                  }
2430  
2431                  if (count($options) > 0) {
2432                      $blogs = $usernode->add(get_string('blogs', 'blog'), null, navigation_node::TYPE_CONTAINER);
2433                      foreach ($options as $type => $option) {
2434                          if ($type == "rss") {
2435                              $blogs->add($option['string'], $option['link'], settings_navigation::TYPE_SETTING, null, null,
2436                                      new pix_icon('i/rss', ''));
2437                          } else {
2438                              $blogs->add($option['string'], $option['link']);
2439                          }
2440                      }
2441                  }
2442              }
2443  
2444              // Add the messages link.
2445              // It is context based so can appear in the user's profile and in course participants information.
2446              if (!empty($CFG->messaging)) {
2447                  $messageargs = array('user1' => $USER->id);
2448                  if ($USER->id != $user->id) {
2449                      $messageargs['user2'] = $user->id;
2450                  }
2451                  $url = new moodle_url('/message/index.php', $messageargs);
2452                  $usernode->add(get_string('messages', 'message'), $url, self::TYPE_SETTING, null, 'messages');
2453              }
2454  
2455              // Add the "My private files" link.
2456              // This link doesn't have a unique display for course context so only display it under the user's profile.
2457              if ($issitecourse && $iscurrentuser && has_capability('moodle/user:manageownfiles', $usercontext)) {
2458                  $url = new moodle_url('/user/files.php');
2459                  $usernode->add(get_string('privatefiles'), $url, self::TYPE_SETTING, null, 'privatefiles');
2460              }
2461  
2462              // Add a node to view the users notes if permitted.
2463              if (!empty($CFG->enablenotes) &&
2464                      has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $coursecontext)) {
2465                  $url = new moodle_url('/notes/index.php', array('user' => $user->id));
2466                  if ($coursecontext->instanceid != SITEID) {
2467                      $url->param('course', $coursecontext->instanceid);
2468                  }
2469                  $usernode->add(get_string('notes', 'notes'), $url);
2470              }
2471  
2472              // Show the grades node.
2473              if (($issitecourse && $iscurrentuser) || has_capability('moodle/user:viewdetails', $usercontext)) {
2474                  require_once($CFG->dirroot . '/user/lib.php');
2475                  // Set the grades node to link to the "Grades" page.
2476                  if ($course->id == SITEID) {
2477                      $url = user_mygrades_url($user->id, $course->id);
2478                  } else { // Otherwise we are in a course and should redirect to the user grade report (Activity report version).
2479                      $url = new moodle_url('/course/user.php', array('mode' => 'grade', 'id' => $course->id, 'user' => $user->id));
2480                  }
2481                  if ($USER->id != $user->id) {
2482                      $usernode->add(get_string('grades', 'grades'), $url, self::TYPE_SETTING, null, 'usergrades');
2483                  } else {
2484                      $usernode->add(get_string('grades', 'grades'), $url);
2485                  }
2486              }
2487  
2488              // If the user is the current user add the repositories for the current user.
2489              $hiddenfields = array_flip(explode(',', $CFG->hiddenuserfields));
2490              if (!$iscurrentuser &&
2491                      $course->id == $SITE->id &&
2492                      has_capability('moodle/user:viewdetails', $usercontext) &&
2493                      (!in_array('mycourses', $hiddenfields) || has_capability('moodle/user:viewhiddendetails', $coursecontext))) {
2494  
2495                  // Add view grade report is permitted.
2496                  $reports = core_component::get_plugin_list('gradereport');
2497                  arsort($reports); // User is last, we want to test it first.
2498  
2499                  $userscourses = enrol_get_users_courses($user->id, false, '*');
2500                  $userscoursesnode = $usernode->add(get_string('courses'));
2501  
2502                  $count = 0;
2503                  foreach ($userscourses as $usercourse) {
2504                      if ($count === (int)$CFG->navcourselimit) {
2505                          $url = new moodle_url('/user/profile.php', array('id' => $user->id, 'showallcourses' => 1));
2506                          $userscoursesnode->add(get_string('showallcourses'), $url);
2507                          break;
2508                      }
2509                      $count++;
2510                      $usercoursecontext = context_course::instance($usercourse->id);
2511                      $usercourseshortname = format_string($usercourse->shortname, true, array('context' => $usercoursecontext));
2512                      $usercoursenode = $userscoursesnode->add($usercourseshortname, new moodle_url('/user/view.php',
2513                              array('id' => $user->id, 'course' => $usercourse->id)), self::TYPE_CONTAINER);
2514  
2515                      $gradeavailable = has_capability('moodle/grade:view', $usercoursecontext);
2516                      if (!$gradeavailable && !empty($usercourse->showgrades) && is_array($reports) && !empty($reports)) {
2517                          foreach ($reports as $plugin => $plugindir) {
2518                              if (has_capability('gradereport/'.$plugin.':view', $usercoursecontext)) {
2519                                  // Stop when the first visible plugin is found.
2520                                  $gradeavailable = true;
2521                                  break;
2522                              }
2523                          }
2524                      }
2525  
2526                      if ($gradeavailable) {
2527                          $url = new moodle_url('/grade/report/index.php', array('id' => $usercourse->id));
2528                          $usercoursenode->add(get_string('grades'), $url, self::TYPE_SETTING, null, null,
2529                                  new pix_icon('i/grades', ''));
2530                      }
2531  
2532                      // Add a node to view the users notes if permitted.
2533                      if (!empty($CFG->enablenotes) &&
2534                              has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $usercoursecontext)) {
2535                          $url = new moodle_url('/notes/index.php', array('user' => $user->id, 'course' => $usercourse->id));
2536                          $usercoursenode->add(get_string('notes', 'notes'), $url, self::TYPE_SETTING);
2537                      }
2538  
2539                      if (can_access_course($usercourse, $user->id, '', true)) {
2540                          $usercoursenode->add(get_string('entercourse'), new moodle_url('/course/view.php',
2541                                  array('id' => $usercourse->id)), self::TYPE_SETTING, null, null, new pix_icon('i/course', ''));
2542                      }
2543  
2544                      $reporttab = $usercoursenode->add(get_string('activityreports'));
2545  
2546                      $reportfunctions = get_plugin_list_with_function('report', 'extend_navigation_user', 'lib.php');
2547                      foreach ($reportfunctions as $reportfunction) {
2548                          $reportfunction($reporttab, $user, $usercourse);
2549                      }
2550  
2551                      $reporttab->trim_if_empty();
2552                  }
2553              }
2554  
2555              // Let plugins hook into user navigation.
2556              $pluginsfunction = get_plugins_with_function('extend_navigation_user', 'lib.php');
2557              foreach ($pluginsfunction as $plugintype => $plugins) {
2558                  if ($plugintype != 'report') {
2559                      foreach ($plugins as $pluginfunction) {
2560                          $pluginfunction($usernode, $user, $usercontext, $course, $coursecontext);
2561                      }
2562                  }
2563              }
2564          }
2565          return true;
2566      }
2567  
2568      /**
2569       * This method simply checks to see if a given module can extend the navigation.
2570       *
2571       * @todo (MDL-25290) A shared caching solution should be used to save details on what extends navigation.
2572       *
2573       * @param string $modname
2574       * @return bool
2575       */
2576      public static function module_extends_navigation($modname) {
2577          global $CFG;
2578          static $extendingmodules = array();
2579          if (!array_key_exists($modname, $extendingmodules)) {
2580              $extendingmodules[$modname] = false;
2581              $file = $CFG->dirroot.'/mod/'.$modname.'/lib.php';
2582              if (file_exists($file)) {
2583                  $function = $modname.'_extend_navigation';
2584                  require_once($file);
2585                  $extendingmodules[$modname] = (function_exists($function));
2586              }
2587          }
2588          return $extendingmodules[$modname];
2589      }
2590      /**
2591       * Extends the navigation for the given user.
2592       *
2593       * @param stdClass $user A user from the database
2594       */
2595      public function extend_for_user($user) {
2596          $this->extendforuser[] = $user;
2597      }
2598  
2599      /**
2600       * Returns all of the users the navigation is being extended for
2601       *
2602       * @return array An array of extending users.
2603       */
2604      public function get_extending_users() {
2605          return $this->extendforuser;
2606      }
2607      /**
2608       * Adds the given course to the navigation structure.
2609       *
2610       * @param stdClass $course
2611       * @param bool $forcegeneric
2612       * @param bool $ismycourse
2613       * @return navigation_node
2614       */
2615      public function add_course(stdClass $course, $forcegeneric = false, $coursetype = self::COURSE_OTHER) {
2616          global $CFG, $SITE;
2617  
2618          // We found the course... we can return it now :)
2619          if (!$forcegeneric && array_key_exists($course->id, $this->addedcourses)) {
2620              return $this->addedcourses[$course->id];
2621          }
2622  
2623          $coursecontext = context_course::instance($course->id);
2624  
2625          if ($coursetype != self::COURSE_MY && $coursetype != self::COURSE_CURRENT && $course->id != $SITE->id) {
2626              if (is_role_switched($course->id)) {
2627                  // user has to be able to access course in order to switch, let's skip the visibility test here
2628              } else if (!core_course_category::can_view_course_info($course)) {
2629                  return false;
2630              }
2631          }
2632  
2633          $issite = ($course->id == $SITE->id);
2634          $shortname = format_string($course->shortname, true, array('context' => $coursecontext));
2635          $fullname = format_string($course->fullname, true, array('context' => $coursecontext));
2636          // This is the name that will be shown for the course.
2637          $coursename = empty($CFG->navshowfullcoursenames) ? $shortname : $fullname;
2638  
2639          if ($coursetype == self::COURSE_CURRENT) {
2640              if ($coursenode = $this->rootnodes['mycourses']->find($course->id, self::TYPE_COURSE)) {
2641                  return $coursenode;
2642              } else {
2643                  $coursetype = self::COURSE_OTHER;
2644              }
2645          }
2646  
2647          // Can the user expand the course to see its content.
2648          $canexpandcourse = true;
2649          if ($issite) {
2650              $parent = $this;
2651              $url = null;
2652              if (empty($CFG->usesitenameforsitepages)) {
2653                  $coursename = get_string('sitepages');
2654              }
2655          } else if ($coursetype == self::COURSE_CURRENT) {
2656              $parent = $this->rootnodes['currentcourse'];
2657              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2658              $canexpandcourse = $this->can_expand_course($course);
2659          } else if ($coursetype == self::COURSE_MY && !$forcegeneric) {
2660              if (!empty($CFG->navshowmycoursecategories) && ($parent = $this->rootnodes['mycourses']->find($course->category, self::TYPE_MY_CATEGORY))) {
2661                  // Nothing to do here the above statement set $parent to the category within mycourses.
2662              } else {
2663                  $parent = $this->rootnodes['mycourses'];
2664              }
2665              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2666          } else {
2667              $parent = $this->rootnodes['courses'];
2668              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2669              // They can only expand the course if they can access it.
2670              $canexpandcourse = $this->can_expand_course($course);
2671              if (!empty($course->category) && $this->show_categories($coursetype == self::COURSE_MY)) {
2672                  if (!$this->is_category_fully_loaded($course->category)) {
2673                      // We need to load the category structure for this course
2674                      $this->load_all_categories($course->category, false);
2675                  }
2676                  if (array_key_exists($course->category, $this->addedcategories)) {
2677                      $parent = $this->addedcategories[$course->category];
2678                      // This could lead to the course being created so we should check whether it is the case again
2679                      if (!$forcegeneric && array_key_exists($course->id, $this->addedcourses)) {
2680                          return $this->addedcourses[$course->id];
2681                      }
2682                  }
2683              }
2684          }
2685  
2686          $coursenode = $parent->add($coursename, $url, self::TYPE_COURSE, $shortname, $course->id, new pix_icon('i/course', ''));
2687          $coursenode->showinflatnavigation = $coursetype == self::COURSE_MY;
2688  
2689          $coursenode->hidden = (!$course->visible);
2690          $coursenode->title(format_string($course->fullname, true, array('context' => $coursecontext, 'escape' => false)));
2691          if ($canexpandcourse) {
2692              // This course can be expanded by the user, make it a branch to make the system aware that its expandable by ajax.
2693              $coursenode->nodetype = self::NODETYPE_BRANCH;
2694              $coursenode->isexpandable = true;
2695          } else {
2696              $coursenode->nodetype = self::NODETYPE_LEAF;
2697              $coursenode->isexpandable = false;
2698          }
2699          if (!$forcegeneric) {
2700              $this->addedcourses[$course->id] = $coursenode;
2701          }
2702  
2703          return $coursenode;
2704      }
2705  
2706      /**
2707       * Returns a cache instance to use for the expand course cache.
2708       * @return cache_session
2709       */
2710      protected function get_expand_course_cache() {
2711          if ($this->cacheexpandcourse === null) {
2712              $this->cacheexpandcourse = cache::make('core', 'navigation_expandcourse');
2713          }
2714          return $this->cacheexpandcourse;
2715      }
2716  
2717      /**
2718       * Checks if a user can expand a course in the navigation.
2719       *
2720       * We use a cache here because in order to be accurate we need to call can_access_course which is a costly function.
2721       * Because this functionality is basic + non-essential and because we lack good event triggering this cache
2722       * permits stale data.
2723       * In the situation the user is granted access to a course after we've initialised this session cache the cache
2724       * will be stale.
2725       * It is brought up to date in only one of two ways.
2726       *   1. The user logs out and in again.
2727       *   2. The user browses to the course they've just being given access to.
2728       *
2729       * Really all this controls is whether the node is shown as expandable or not. It is uber un-important.
2730       *
2731       * @param stdClass $course
2732       * @return bool
2733       */
2734      protected function can_expand_course($course) {
2735          $cache = $this->get_expand_course_cache();
2736          $canexpand = $cache->get($course->id);
2737          if ($canexpand === false) {
2738              $canexpand = isloggedin() && can_access_course($course, null, '', true);
2739              $canexpand = (int)$canexpand;
2740              $cache->set($course->id, $canexpand);
2741          }
2742          return ($canexpand === 1);
2743      }
2744  
2745      /**
2746       * Returns true if the category has already been loaded as have any child categories
2747       *
2748       * @param int $categoryid
2749       * @return bool
2750       */
2751      protected function is_category_fully_loaded($categoryid) {
2752          return (array_key_exists($categoryid, $this->addedcategories) && ($this->allcategoriesloaded || $this->addedcategories[$categoryid]->children->count() > 0));
2753      }
2754  
2755      /**
2756       * Adds essential course nodes to the navigation for the given course.
2757       *
2758       * This method adds nodes such as reports, blogs and participants
2759       *
2760       * @param navigation_node $coursenode
2761       * @param stdClass $course
2762       * @return bool returns true on successful addition of a node.
2763       */
2764      public function add_course_essentials($coursenode, stdClass $course) {
2765          global $CFG, $SITE;
2766          require_once($CFG->dirroot . '/course/lib.php');
2767  
2768          if ($course->id == $SITE->id) {
2769              return $this->add_front_page_course_essentials($coursenode, $course);
2770          }
2771  
2772          if ($coursenode == false || !($coursenode instanceof navigation_node) || $coursenode->get('participants', navigation_node::TYPE_CONTAINER)) {
2773              return true;
2774          }
2775  
2776          $navoptions = course_get_user_navigation_options($this->page->context, $course);
2777  
2778          //Participants
2779          if ($navoptions->participants) {
2780              $participants = $coursenode->add(get_string('participants'), new moodle_url('/user/index.php?id='.$course->id),
2781                  self::TYPE_CONTAINER, get_string('participants'), 'participants', new pix_icon('i/users', ''));
2782  
2783              if ($navoptions->blogs) {
2784                  $blogsurls = new moodle_url('/blog/index.php');
2785                  if ($currentgroup = groups_get_course_group($course, true)) {
2786                      $blogsurls->param('groupid', $currentgroup);
2787                  } else {
2788                      $blogsurls->param('courseid', $course->id);
2789                  }
2790                  $participants->add(get_string('blogscourse', 'blog'), $blogsurls->out(), self::TYPE_SETTING, null, 'courseblogs');
2791              }
2792  
2793              if ($navoptions->notes) {
2794                  $participants->add(get_string('notes', 'notes'), new moodle_url('/notes/index.php', array('filtertype' => 'course', 'filterselect' => $course->id)), self::TYPE_SETTING, null, 'currentcoursenotes');
2795              }
2796          } else if (count($this->extendforuser) > 0 || $this->page->course->id == $course->id) {
2797              $participants = $coursenode->add(get_string('participants'), null, self::TYPE_CONTAINER, get_string('participants'), 'participants');
2798          }
2799  
2800          // Badges.
2801          if ($navoptions->badges) {
2802              $url = new moodle_url('/badges/view.php', array('type' => 2, 'id' => $course->id));
2803  
2804              $coursenode->add(get_string('coursebadges', 'badges'), $url,
2805                      navigation_node::TYPE_SETTING, null, 'badgesview',
2806                      new pix_icon('i/badge', get_string('coursebadges', 'badges')));
2807          }
2808  
2809          // Check access to the course and competencies page.
2810          if ($navoptions->competencies) {
2811              // Just a link to course competency.
2812              $title = get_string('competencies', 'core_competency');
2813              $path = new moodle_url("/admin/tool/lp/coursecompetencies.php", array('courseid' => $course->id));
2814              $coursenode->add($title, $path, navigation_node::TYPE_SETTING, null, 'competencies',
2815                      new pix_icon('i/competencies', ''));
2816          }
2817          if ($navoptions->grades) {
2818              $url = new moodle_url('/grade/report/index.php', array('id'=>$course->id));
2819              $gradenode = $coursenode->add(get_string('grades'), $url, self::TYPE_SETTING, null,
2820                  'grades', new pix_icon('i/grades', ''));
2821              // If the page type matches the grade part, then make the nav drawer grade node (incl. all sub pages) active.
2822              if ($this->page->context->contextlevel < CONTEXT_MODULE && strpos($this->page->pagetype, 'grade-') === 0) {
2823                  $gradenode->make_active();
2824              }
2825          }
2826  
2827          return true;
2828      }
2829      /**
2830       * This generates the structure of the course that won't be generated when
2831       * the modules and sections are added.
2832       *
2833       * Things such as the reports branch, the participants branch, blogs... get
2834       * added to the course node by this method.
2835       *
2836       * @param navigation_node $coursenode
2837       * @param stdClass $course
2838       * @return bool True for successfull generation
2839       */
2840      public function add_front_page_course_essentials(navigation_node $coursenode, stdClass $course) {
2841          global $CFG, $USER, $COURSE, $SITE;
2842          require_once($CFG->dirroot . '/course/lib.php');
2843  
2844          if ($coursenode == false || $coursenode->get('frontpageloaded', navigation_node::TYPE_CUSTOM)) {
2845              return true;
2846          }
2847  
2848          $systemcontext = context_system::instance();
2849          $navoptions = course_get_user_navigation_options($systemcontext, $course);
2850  
2851          // Hidden node that we use to determine if the front page navigation is loaded.
2852          // This required as there are not other guaranteed nodes that may be loaded.
2853          $coursenode->add('frontpageloaded', null, self::TYPE_CUSTOM, null, 'frontpageloaded')->display = false;
2854  
2855          // Participants.
2856          if ($navoptions->participants) {
2857              $coursenode->add(get_string('participants'), new moodle_url('/user/index.php?id='.$course->id), self::TYPE_CUSTOM, get_string('participants'), 'participants');
2858          }
2859  
2860          // Blogs.
2861          if ($navoptions->blogs) {
2862              $blogsurls = new moodle_url('/blog/index.php');
2863              $coursenode->add(get_string('blogssite', 'blog'), $blogsurls->out(), self::TYPE_SYSTEM, null, 'siteblog');
2864          }
2865  
2866          $filterselect = 0;
2867  
2868          // Badges.
2869          if ($navoptions->badges) {
2870              $url = new moodle_url($CFG->wwwroot . '/badges/view.php', array('type' => 1));
2871              $coursenode->add(get_string('sitebadges', 'badges'), $url, navigation_node::TYPE_CUSTOM);
2872          }
2873  
2874          // Notes.
2875          if ($navoptions->notes) {
2876              $coursenode->add(get_string('notes', 'notes'), new moodle_url('/notes/index.php',
2877                  array('filtertype' => 'course', 'filterselect' => $filterselect)), self::TYPE_SETTING, null, 'notes');
2878          }
2879  
2880          // Tags
2881          if ($navoptions->tags) {
2882              $node = $coursenode->add(get_string('tags', 'tag'), new moodle_url('/tag/search.php'),
2883                      self::TYPE_SETTING, null, 'tags');
2884          }
2885  
2886          // Search.
2887          if ($navoptions->search) {
2888              $node = $coursenode->add(get_string('search', 'search'), new moodle_url('/search/index.php'),
2889                      self::TYPE_SETTING, null, 'search');
2890          }
2891  
2892          if ($navoptions->calendar) {
2893              $courseid = $COURSE->id;
2894              $params = array('view' => 'month');
2895              if ($courseid != $SITE->id) {
2896                  $params['course'] = $courseid;
2897              }
2898  
2899              // Calendar
2900              $calendarurl = new moodle_url('/calendar/view.php', $params);
2901              $node = $coursenode->add(get_string('calendar', 'calendar'), $calendarurl,
2902                  self::TYPE_CUSTOM, null, 'calendar', new pix_icon('i/calendar', ''));
2903              $node->showinflatnavigation = true;
2904          }
2905  
2906          if (isloggedin()) {
2907              $usercontext = context_user::instance($USER->id);
2908              if (has_capability('moodle/user:manageownfiles', $usercontext)) {
2909                  $url = new moodle_url('/user/files.php');
2910                  $node = $coursenode->add(get_string('privatefiles'), $url,
2911                      self::TYPE_SETTING, null, 'privatefiles', new pix_icon('i/privatefiles', ''));
2912                  $node->display = false;
2913                  $node->showinflatnavigation = true;
2914              }
2915          }
2916  
2917          if (isloggedin()) {
2918              $context = $this->page->context;
2919              switch ($context->contextlevel) {
2920                  case CONTEXT_COURSECAT:
2921                      // OK, expected context level.
2922                      break;
2923                  case CONTEXT_COURSE:
2924                      // OK, expected context level if not on frontpage.
2925                      if ($COURSE->id != $SITE->id) {
2926                          break;
2927                      }
2928                  default:
2929                      // If this context is part of a course (excluding frontpage), use the course context.
2930                      // Otherwise, use the system context.
2931                      $coursecontext = $context->get_course_context(false);
2932                      if ($coursecontext && $coursecontext->instanceid !== $SITE->id) {
2933                          $context = $coursecontext;
2934                      } else {
2935                          $context = $systemcontext;
2936                      }
2937              }
2938  
2939              $params = ['contextid' => $context->id];
2940              if (has_capability('moodle/contentbank:access', $context)) {
2941                  $url = new moodle_url('/contentbank/index.php', $params);
2942                  $node = $coursenode->add(get_string('contentbank'), $url,
2943                      self::TYPE_CUSTOM, null, 'contentbank', new pix_icon('i/contentbank', ''));
2944                  $node->showinflatnavigation = true;
2945              }
2946          }
2947  
2948          return true;
2949      }
2950  
2951      /**
2952       * Clears the navigation cache
2953       */
2954      public function clear_cache() {
2955          $this->cache->clear();
2956      }
2957  
2958      /**
2959       * Sets an expansion limit for the navigation
2960       *
2961       * The expansion limit is used to prevent the display of content that has a type
2962       * greater than the provided $type.
2963       *
2964       * Can be used to ensure things such as activities or activity content don't get
2965       * shown on the navigation.
2966       * They are still generated in order to ensure the navbar still makes sense.
2967       *
2968       * @param int $type One of navigation_node::TYPE_*
2969       * @return bool true when complete.
2970       */
2971      public function set_expansion_limit($type) {
2972          global $SITE;
2973          $nodes = $this->find_all_of_type($type);
2974  
2975          // We only want to hide specific types of nodes.
2976          // Only nodes that represent "structure" in the navigation tree should be hidden.
2977          // If we hide all nodes then we risk hiding vital information.
2978          $typestohide = array(
2979              self::TYPE_CATEGORY,
2980              self::TYPE_COURSE,
2981              self::TYPE_SECTION,
2982              self::TYPE_ACTIVITY
2983          );
2984  
2985          foreach ($nodes as $node) {
2986              // We need to generate the full site node
2987              if ($type == self::TYPE_COURSE && $node->key == $SITE->id) {
2988                  continue;
2989              }
2990              foreach ($node->children as $child) {
2991                  $child->hide($typestohide);
2992              }
2993          }
2994          return true;
2995      }
2996      /**
2997       * Attempts to get the navigation with the given key from this nodes children.
2998       *
2999       * This function only looks at this nodes children, it does NOT look recursivily.
3000       * If the node can't be found then false is returned.
3001       *
3002       * If you need to search recursivily then use the {@link global_navigation::find()} method.
3003       *
3004       * Note: If you are trying to set the active node {@link navigation_node::override_active_url()}
3005       * may be of more use to you.
3006       *
3007       * @param string|int $key The key of the node you wish to receive.
3008       * @param int $type One of navigation_node::TYPE_*
3009       * @return navigation_node|false
3010       */
3011      public function get($key, $type = null) {
3012          if (!$this->initialised) {
3013              $this->initialise();
3014          }
3015          return parent::get($key, $type);
3016      }
3017  
3018      /**
3019       * Searches this nodes children and their children to find a navigation node
3020       * with the matching key and type.
3021       *
3022       * This method is recursive and searches children so until either a node is
3023       * found or there are no more nodes to search.
3024       *
3025       * If you know that the node being searched for is a child of this node
3026       * then use the {@link global_navigation::get()} method instead.
3027       *
3028       * Note: If you are trying to set the active node {@link navigation_node::override_active_url()}
3029       * may be of more use to you.
3030       *
3031       * @param string|int $key The key of the node you wish to receive.
3032       * @param int $type One of navigation_node::TYPE_*
3033       * @return navigation_node|false
3034       */
3035      public function find($key, $type) {
3036          if (!$this->initialised) {
3037              $this->initialise();
3038          }
3039          if ($type == self::TYPE_ROOTNODE && array_key_exists($key, $this->rootnodes)) {
3040              return $this->rootnodes[$key];
3041          }
3042          return parent::find($key, $type);
3043      }
3044  
3045      /**
3046       * They've expanded the 'my courses' branch.
3047       */
3048      protected function load_courses_enrolled() {
3049          global $CFG;
3050  
3051          $limit = (int) $CFG->navcourselimit;
3052  
3053          $courses = enrol_get_my_courses('*');
3054          $flatnavcourses = [];
3055  
3056          // Go through the courses and see which ones we want to display in the flatnav.
3057          foreach ($courses as $course) {
3058              $classify = course_classify_for_timeline($course);
3059  
3060              if ($classify == COURSE_TIMELINE_INPROGRESS) {
3061                  $flatnavcourses[$course->id] = $course;
3062              }
3063          }
3064  
3065          // Get the number of courses that can be displayed in the nav block and in the flatnav.
3066          $numtotalcourses = count($courses);
3067          $numtotalflatnavcourses = count($flatnavcourses);
3068  
3069          // Reduce the size of the arrays to abide by the 'navcourselimit' setting.
3070          $courses = array_slice($courses, 0, $limit, true);
3071          $flatnavcourses = array_slice($flatnavcourses, 0, $limit, true);
3072  
3073          // Get the number of courses we are going to show for each.
3074          $numshowncourses = count($courses);
3075          $numshownflatnavcourses = count($flatnavcourses);
3076          if ($numshowncourses && $this->show_my_categories()) {
3077              // Generate an array containing unique values of all the courses' categories.
3078              $categoryids = array();
3079              foreach ($courses as $course) {
3080                  if (in_array($course->category, $categoryids)) {
3081                      continue;
3082                  }
3083                  $categoryids[] = $course->category;
3084              }
3085  
3086              // Array of category IDs that include the categories of the user's courses and the related course categories.
3087              $fullpathcategoryids = [];
3088              // Get the course categories for the enrolled courses' category IDs.
3089              $mycoursecategories = core_course_category::get_many($categoryids);
3090              // Loop over each of these categories and build the category tree using each category's path.
3091              foreach ($mycoursecategories as $mycoursecat) {
3092                  $pathcategoryids = explode('/', $mycoursecat->path);
3093                  // First element of the exploded path is empty since paths begin with '/'.
3094                  array_shift($pathcategoryids);
3095                  // Merge the exploded category IDs into the full list of category IDs that we will fetch.
3096                  $fullpathcategoryids = array_merge($fullpathcategoryids, $pathcategoryids);
3097              }
3098  
3099              // Fetch all of the categories related to the user's courses.
3100              $pathcategories = core_course_category::get_many($fullpathcategoryids);
3101              // Loop over each of these categories and build the category tree.
3102              foreach ($pathcategories as $coursecat) {
3103                  // No need to process categories that have already been added.
3104                  if (isset($this->addedcategories[$coursecat->id])) {
3105                      continue;
3106                  }
3107                  // Skip categories that are not visible.
3108                  if (!$coursecat->is_uservisible()) {
3109                      continue;
3110                  }
3111  
3112                  // Get this course category's parent node.
3113                  $parent = null;
3114                  if ($coursecat->parent && isset($this->addedcategories[$coursecat->parent])) {
3115                      $parent = $this->addedcategories[$coursecat->parent];
3116                  }
3117                  if (!$parent) {
3118                      // If it has no parent, then it should be right under the My courses node.
3119                      $parent = $this->rootnodes['mycourses'];
3120                  }
3121  
3122                  // Build the category object based from the coursecat object.
3123                  $mycategory = new stdClass();
3124                  $mycategory->id = $coursecat->id;
3125                  $mycategory->name = $coursecat->name;
3126                  $mycategory->visible = $coursecat->visible;
3127  
3128                  // Add this category to the nav tree.
3129                  $this->add_category($mycategory, $parent, self::TYPE_MY_CATEGORY);
3130              }
3131          }
3132  
3133          // Go through each course now and add it to the nav block, and the flatnav if applicable.
3134          foreach ($courses as $course) {
3135              $node = $this->add_course($course, false, self::COURSE_MY);
3136              if ($node) {
3137                  $node->showinflatnavigation = false;
3138                  // Check if we should also add this to the flat nav as well.
3139                  if (isset($flatnavcourses[$course->id])) {
3140                      $node->showinflatnavigation = true;
3141                  }
3142              }
3143          }
3144  
3145          // Go through each course in the flatnav now.
3146          foreach ($flatnavcourses as $course) {
3147              // Check if we haven't already added it.
3148              if (!isset($courses[$course->id])) {
3149                  // Ok, add it to the flatnav only.
3150                  $node = $this->add_course($course, false, self::COURSE_MY);
3151                  $node->display = false;
3152                  $node->showinflatnavigation = true;
3153              }
3154          }
3155  
3156          $showmorelinkinnav = $numtotalcourses > $numshowncourses;
3157          $showmorelinkinflatnav = $numtotalflatnavcourses > $numshownflatnavcourses;
3158          // Show a link to the course page if there are more courses the user is enrolled in.
3159          if ($showmorelinkinnav || $showmorelinkinflatnav) {
3160              // Adding hash to URL so the link is not highlighted in the navigation when clicked.
3161              $url = new moodle_url('/my/');
3162              $parent = $this->rootnodes['mycourses'];
3163              $coursenode = $parent->add(get_string('morenavigationlinks'), $url, self::TYPE_CUSTOM, null, self::COURSE_INDEX_PAGE);
3164  
3165              if ($showmorelinkinnav) {
3166                  $coursenode->display = true;
3167              }
3168  
3169              if ($showmorelinkinflatnav) {
3170                  $coursenode->showinflatnavigation = true;
3171              }
3172          }
3173      }
3174  }
3175  
3176  /**
3177   * The global navigation class used especially for AJAX requests.
3178   *
3179   * The primary methods that are used in the global navigation class have been overriden
3180   * to ensure that only the relevant branch is generated at the root of the tree.
3181   * This can be done because AJAX is only used when the backwards structure for the
3182   * requested branch exists.
3183   * This has been done only because it shortens the amounts of information that is generated
3184   * which of course will speed up the response time.. because no one likes laggy AJAX.
3185   *
3186   * @package   core
3187   * @category  navigation
3188   * @copyright 2009 Sam Hemelryk
3189   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3190   */
3191  class global_navigation_for_ajax extends global_navigation {
3192  
3193      /** @var int used for determining what type of navigation_node::TYPE_* is being used */
3194      protected $branchtype;
3195  
3196      /** @var int the instance id */
3197      protected $instanceid;
3198  
3199      /** @var array Holds an array of expandable nodes */
3200      protected $expandable = array();
3201  
3202      /**
3203       * Constructs the navigation for use in an AJAX request
3204       *
3205       * @param moodle_page $page moodle_page object
3206       * @param int $branchtype
3207       * @param int $id
3208       */
3209      public function __construct($page, $branchtype, $id) {
3210          $this->page = $page;
3211          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
3212          $this->children = new navigation_node_collection();
3213          $this->branchtype = $branchtype;
3214          $this->instanceid = $id;
3215          $this->initialise();
3216      }
3217      /**
3218       * Initialise the navigation given the type and id for the branch to expand.
3219       *
3220       * @return array An array of the expandable nodes
3221       */
3222      public function initialise() {
3223          global $DB, $SITE;
3224  
3225          if ($this->initialised || during_initial_install()) {
3226              return $this->expandable;
3227          }
3228          $this->initialised = true;
3229  
3230          $this->rootnodes = array();
3231          $this->rootnodes['site']    = $this->add_course($SITE);
3232          $this->rootnodes['mycourses'] = $this->add(get_string('mycourses'), new moodle_url('/my'), self::TYPE_ROOTNODE, null, 'mycourses');
3233          $this->rootnodes['courses'] = $this->add(get_string('courses'), null, self::TYPE_ROOTNODE, null, 'courses');
3234          // The courses branch is always displayed, and is always expandable (although may be empty).
3235          // This mimicks what is done during {@link global_navigation::initialise()}.
3236          $this->rootnodes['courses']->isexpandable = true;
3237  
3238          // Branchtype will be one of navigation_node::TYPE_*
3239          switch ($this->branchtype) {
3240              case 0:
3241                  if ($this->instanceid === 'mycourses') {
3242                      $this->load_courses_enrolled();
3243                  } else if ($this->instanceid === 'courses') {
3244                      $this->load_courses_other();
3245                  }
3246                  break;
3247              case self::TYPE_CATEGORY :
3248                  $this->load_category($this->instanceid);
3249                  break;
3250              case self::TYPE_MY_CATEGORY :
3251                  $this->load_category($this->instanceid, self::TYPE_MY_CATEGORY);
3252                  break;
3253              case self::TYPE_COURSE :
3254                  $course = $DB->get_record('course', array('id' => $this->instanceid), '*', MUST_EXIST);
3255                  if (!can_access_course($course, null, '', true)) {
3256                      // Thats OK all courses are expandable by default. We don't need to actually expand it we can just
3257                      // add the course node and break. This leads to an empty node.
3258                      $this->add_course($course);
3259                      break;
3260                  }
3261                  require_course_login($course, true, null, false, true);
3262                  $this->page->set_context(context_course::instance($course->id));
3263                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
3264                  $this->add_course_essentials($coursenode, $course);
3265                  $this->load_course_sections($course, $coursenode);
3266                  break;
3267              case self::TYPE_SECTION :
3268                  $sql = 'SELECT c.*, cs.section AS sectionnumber
3269                          FROM {course} c
3270                          LEFT JOIN {course_sections} cs ON cs.course = c.id
3271                          WHERE cs.id = ?';
3272                  $course = $DB->get_record_sql($sql, array($this->instanceid), MUST_EXIST);
3273                  require_course_login($course, true, null, false, true);
3274                  $this->page->set_context(context_course::instance($course->id));
3275                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
3276                  $this->add_course_essentials($coursenode, $course);
3277                  $this->load_course_sections($course, $coursenode, $course->sectionnumber);
3278                  break;
3279              case self::TYPE_ACTIVITY :
3280                  $sql = "SELECT c.*
3281                            FROM {course} c
3282                            JOIN {course_modules} cm ON cm.course = c.id
3283                           WHERE cm.id = :cmid";
3284                  $params = array('cmid' => $this->instanceid);
3285                  $course = $DB->get_record_sql($sql, $params, MUST_EXIST);
3286                  $modinfo = get_fast_modinfo($course);
3287                  $cm = $modinfo->get_cm($this->instanceid);
3288                  require_course_login($course, true, $cm, false, true);
3289                  $this->page->set_context(context_module::instance($cm->id));
3290                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
3291                  $this->load_course_sections($course, $coursenode, null, $cm);
3292                  $activitynode = $coursenode->find($cm->id, self::TYPE_ACTIVITY);
3293                  if ($activitynode) {
3294                      $modulenode = $this->load_activity($cm, $course, $activitynode);
3295                  }
3296                  break;
3297              default:
3298                  throw new Exception('Unknown type');
3299                  return $this->expandable;
3300          }
3301  
3302          if ($this->page->context->contextlevel == CONTEXT_COURSE && $this->page->context->instanceid != $SITE->id) {
3303              $this->load_for_user(null, true);
3304          }
3305  
3306          // Give the local plugins a chance to include some navigation if they want.
3307          $this->load_local_plugin_navigation();
3308  
3309          $this->find_expandable($this->expandable);
3310          return $this->expandable;
3311      }
3312  
3313      /**
3314       * They've expanded the general 'courses' branch.
3315       */
3316      protected function load_courses_other() {
3317          $this->load_all_courses();
3318      }
3319  
3320      /**
3321       * Loads a single category into the AJAX navigation.
3322       *
3323       * This function is special in that it doesn't concern itself with the parent of
3324       * the requested category or its siblings.
3325       * This is because with the AJAX navigation we know exactly what is wanted and only need to
3326       * request that.
3327       *
3328       * @global moodle_database $DB
3329       * @param int $categoryid id of category to load in navigation.
3330       * @param int $nodetype type of node, if category is under MyHome then it's TYPE_MY_CATEGORY
3331       * @return void.
3332       */
3333      protected function load_category($categoryid, $nodetype = self::TYPE_CATEGORY) {
3334          global $CFG, $DB;
3335  
3336          $limit = 20;
3337          if (!empty($CFG->navcourselimit)) {
3338              $limit = (int)$CFG->navcourselimit;
3339          }
3340  
3341          $catcontextsql = context_helper::get_preload_record_columns_sql('ctx');
3342          $sql = "SELECT cc.*, $catcontextsql
3343                    FROM {course_categories} cc
3344                    JOIN {context} ctx ON cc.id = ctx.instanceid
3345                   WHERE ctx.contextlevel = ".CONTEXT_COURSECAT." AND
3346                         (cc.id = :categoryid1 OR cc.parent = :categoryid2)
3347                ORDER BY cc.depth ASC, cc.sortorder ASC, cc.id ASC";
3348          $params = array('categoryid1' => $categoryid, 'categoryid2' => $categoryid);
3349          $categories = $DB->get_recordset_sql($sql, $params, 0, $limit);
3350          $categorylist = array();
3351          $subcategories = array();
3352          $basecategory = null;
3353          foreach ($categories as $category) {
3354              $categorylist[] = $category->id;
3355              context_helper::preload_from_record($category);
3356              if ($category->id == $categoryid) {
3357                  $this->add_category($category, $this, $nodetype);
3358                  $basecategory = $this->addedcategories[$category->id];
3359              } else {
3360                  $subcategories[$category->id] = $category;
3361              }
3362          }
3363          $categories->close();
3364  
3365  
3366          // If category is shown in MyHome then only show enrolled courses and hide empty subcategories,
3367          // else show all courses.
3368          if ($nodetype === self::TYPE_MY_CATEGORY) {
3369              $courses = enrol_get_my_courses('*');
3370              $categoryids = array();
3371  
3372              // Only search for categories if basecategory was found.
3373              if (!is_null($basecategory)) {
3374                  // Get course parent category ids.
3375                  foreach ($courses as $course) {
3376                      $categoryids[] = $course->category;
3377                  }
3378  
3379                  // Get a unique list of category ids which a part of the path
3380                  // to user's courses.
3381                  $coursesubcategories = array();
3382                  $addedsubcategories = array();
3383  
3384                  list($sql, $params) = $DB->get_in_or_equal($categoryids);
3385                  $categories = $DB->get_recordset_select('course_categories', 'id '.$sql, $params, 'sortorder, id', 'id, path');
3386  
3387                  foreach ($categories as $category){
3388                      $coursesubcategories = array_merge($coursesubcategories, explode('/', trim($category->path, "/")));
3389                  }
3390                  $categories->close();
3391                  $coursesubcategories = array_unique($coursesubcategories);
3392  
3393                  // Only add a subcategory if it is part of the path to user's course and
3394                  // wasn't already added.
3395                  foreach ($subcategories as $subid => $subcategory) {
3396                      if (in_array($subid, $coursesubcategories) &&
3397                              !in_array($subid, $addedsubcategories)) {
3398                              $this->add_category($subcategory, $basecategory, $nodetype);
3399                              $addedsubcategories[] = $subid;
3400                      }
3401                  }
3402              }
3403  
3404              foreach ($courses as $course) {
3405                  // Add course if it's in category.
3406                  if (in_array($course->category, $categorylist)) {
3407                      $this->add_course($course, true, self::COURSE_MY);
3408                  }
3409              }
3410          } else {
3411              if (!is_null($basecategory)) {
3412                  foreach ($subcategories as $key=>$category) {
3413                      $this->add_category($category, $basecategory, $nodetype);
3414                  }
3415              }
3416              $courses = $DB->get_recordset('course', array('category' => $categoryid), 'sortorder', '*' , 0, $limit);
3417              foreach ($courses as $course) {
3418                  $this->add_course($course);
3419              }
3420              $courses->close();
3421          }
3422      }
3423  
3424      /**
3425       * Returns an array of expandable nodes
3426       * @return array
3427       */
3428      public function get_expandable() {
3429          return $this->expandable;
3430      }
3431  }
3432  
3433  /**
3434   * Navbar class
3435   *
3436   * This class is used to manage the navbar, which is initialised from the navigation
3437   * object held by PAGE
3438   *
3439   * @package   core
3440   * @category  navigation
3441   * @copyright 2009 Sam Hemelryk
3442   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3443   */
3444  class navbar extends navigation_node {
3445      /** @var bool A switch for whether the navbar is initialised or not */
3446      protected $initialised = false;
3447      /** @var mixed keys used to reference the nodes on the navbar */
3448      protected $keys = array();
3449      /** @var null|string content of the navbar */
3450      protected $content = null;
3451      /** @var moodle_page object the moodle page that this navbar belongs to */
3452      protected $page;
3453      /** @var bool A switch for whether to ignore the active navigation information */
3454      protected $ignoreactive = false;
3455      /** @var bool A switch to let us know if we are in the middle of an install */
3456      protected $duringinstall = false;
3457      /** @var bool A switch for whether the navbar has items */
3458      protected $hasitems = false;
3459      /** @var array An array of navigation nodes for the navbar */
3460      protected $items;
3461      /** @var array An array of child node objects */
3462      public $children = array();
3463      /** @var bool A switch for whether we want to include the root node in the navbar */
3464      public $includesettingsbase = false;
3465      /** @var breadcrumb_navigation_node[] $prependchildren */
3466      protected $prependchildren = array();
3467  
3468      /**
3469       * The almighty constructor
3470       *
3471       * @param moodle_page $page
3472       */
3473      public function __construct(moodle_page $page) {
3474          global $CFG;
3475          if (during_initial_install()) {
3476              $this->duringinstall = true;
3477              return false;
3478          }
3479          $this->page = $page;
3480          $this->text = get_string('home');
3481          $this->shorttext = get_string('home');
3482          $this->action = new moodle_url($CFG->wwwroot);
3483          $this->nodetype = self::NODETYPE_BRANCH;
3484          $this->type = self::TYPE_SYSTEM;
3485      }
3486  
3487      /**
3488       * Quick check to see if the navbar will have items in.
3489       *
3490       * @return bool Returns true if the navbar will have items, false otherwise
3491       */
3492      public function has_items() {
3493          if ($this->duringinstall) {
3494              return false;
3495          } else if ($this->hasitems !== false) {
3496              return true;
3497          }
3498          if (count($this->children) > 0 || count($this->prependchildren) > 0) {
3499              // There have been manually added items - there are definitely items.
3500              $outcome = true;
3501          } else if (!$this->ignoreactive) {
3502              // We will need to initialise the navigation structure to check if there are active items.
3503              $this->page->navigation->initialise($this->page);
3504              $outcome = ($this->page->navigation->contains_active_node() || $this->page->settingsnav->contains_active_node());
3505          }
3506          $this->hasitems = $outcome;
3507          return $outcome;
3508      }
3509  
3510      /**
3511       * Turn on/off ignore active
3512       *
3513       * @param bool $setting
3514       */
3515      public function ignore_active($setting=true) {
3516          $this->ignoreactive = ($setting);
3517      }
3518  
3519      /**
3520       * Gets a navigation node
3521       *
3522       * @param string|int $key for referencing the navbar nodes
3523       * @param int $type breadcrumb_navigation_node::TYPE_*
3524       * @return breadcrumb_navigation_node|bool
3525       */
3526      public function get($key, $type = null) {
3527          foreach ($this->children as &$child) {
3528              if ($child->key === $key && ($type == null || $type == $child->type)) {
3529                  return $child;
3530              }
3531          }
3532          foreach ($this->prependchildren as &$child) {
3533              if ($child->key === $key && ($type == null || $type == $child->type)) {
3534                  return $child;
3535              }
3536          }
3537          return false;
3538      }
3539      /**
3540       * Returns an array of breadcrumb_navigation_nodes that make up the navbar.
3541       *
3542       * @return array
3543       */
3544      public function get_items() {
3545          global $CFG;
3546          $items = array();
3547          // Make sure that navigation is initialised
3548          if (!$this->has_items()) {
3549              return $items;
3550          }
3551          if ($this->items !== null) {
3552              return $this->items;
3553          }
3554  
3555          if (count($this->children) > 0) {
3556              // Add the custom children.
3557              $items = array_reverse($this->children);
3558          }
3559  
3560          // Check if navigation contains the active node
3561          if (!$this->ignoreactive) {
3562              // We will need to ensure the navigation has been initialised.
3563              $this->page->navigation->initialise($this->page);
3564              // Now find the active nodes on both the navigation and settings.
3565              $navigationactivenode = $this->page->navigation->find_active_node();
3566              $settingsactivenode = $this->page->settingsnav->find_active_node();
3567  
3568              if ($navigationactivenode && $settingsactivenode) {
3569                  // Parse a combined navigation tree
3570                  while ($settingsactivenode && $settingsactivenode->parent !== null) {
3571                      if (!$settingsactivenode->mainnavonly) {
3572                          $items[] = new breadcrumb_navigation_node($settingsactivenode);
3573                      }
3574                      $settingsactivenode = $settingsactivenode->parent;
3575                  }
3576                  if (!$this->includesettingsbase) {
3577                      // Removes the first node from the settings (root node) from the list
3578                      array_pop($items);
3579                  }
3580                  while ($navigationactivenode && $navigationactivenode->parent !== null) {
3581                      if (!$navigationactivenode->mainnavonly) {
3582                          $items[] = new breadcrumb_navigation_node($navigationactivenode);
3583                      }
3584                      if (!empty($CFG->navshowcategories) &&
3585                              $navigationactivenode->type === self::TYPE_COURSE &&
3586                              $navigationactivenode->parent->key === 'currentcourse') {
3587                          foreach ($this->get_course_categories() as $item) {
3588                              $items[] = new breadcrumb_navigation_node($item);
3589                          }
3590                      }
3591                      $navigationactivenode = $navigationactivenode->parent;
3592                  }
3593              } else if ($navigationactivenode) {
3594                  // Parse the navigation tree to get the active node
3595                  while ($navigationactivenode && $navigationactivenode->parent !== null) {
3596                      if (!$navigationactivenode->mainnavonly) {
3597                          $items[] = new breadcrumb_navigation_node($navigationactivenode);
3598                      }
3599                      if (!empty($CFG->navshowcategories) &&
3600                              $navigationactivenode->type === self::TYPE_COURSE &&
3601                              $navigationactivenode->parent->key === 'currentcourse') {
3602                          foreach ($this->get_course_categories() as $item) {
3603                              $items[] = new breadcrumb_navigation_node($item);
3604                          }
3605                      }
3606                      $navigationactivenode = $navigationactivenode->parent;
3607                  }
3608              } else if ($settingsactivenode) {
3609                  // Parse the settings navigation to get the active node
3610                  while ($settingsactivenode && $settingsactivenode->parent !== null) {
3611                      if (!$settingsactivenode->mainnavonly) {
3612                          $items[] = new breadcrumb_navigation_node($settingsactivenode);
3613                      }
3614                      $settingsactivenode = $settingsactivenode->parent;
3615                  }
3616              }
3617          }
3618  
3619          $items[] = new breadcrumb_navigation_node(array(
3620              'text' => $this->page->navigation->text,
3621              'shorttext' => $this->page->navigation->shorttext,
3622              'key' => $this->page->navigation->key,
3623              'action' => $this->page->navigation->action
3624          ));
3625  
3626          if (count($this->prependchildren) > 0) {
3627              // Add the custom children
3628              $items = array_merge($items, array_reverse($this->prependchildren));
3629          }
3630  
3631          $last = reset($items);
3632          if ($last) {
3633              $last->set_last(true);
3634          }
3635          $this->items = array_reverse($items);
3636          return $this->items;
3637      }
3638  
3639      /**
3640       * Get the list of categories leading to this course.
3641       *
3642       * This function is used by {@link navbar::get_items()} to add back the "courses"
3643       * node and category chain leading to the current course.  Note that this is only ever
3644       * called for the current course, so we don't need to bother taking in any parameters.
3645       *
3646       * @return array
3647       */
3648      private function get_course_categories() {
3649          global $CFG;
3650          require_once($CFG->dirroot.'/course/lib.php');
3651  
3652          $categories = array();
3653          $cap = 'moodle/category:viewhiddencategories';
3654          $showcategories = !core_course_category::is_simple_site();
3655  
3656          if ($showcategories) {
3657              foreach ($this->page->categories as $category) {
3658                  $context = context_coursecat::instance($category->id);
3659                  if (!core_course_category::can_view_category($category)) {
3660                      continue;
3661                  }
3662                  $url = new moodle_url('/course/index.php', array('categoryid' => $category->id));
3663                  $name = format_string($category->name, true, array('context' => $context));
3664                  $categorynode = breadcrumb_navigation_node::create($name, $url, self::TYPE_CATEGORY, null, $category->id);
3665                  if (!$category->visible) {
3666                      $categorynode->hidden = true;
3667                  }
3668                  $categories[] = $categorynode;
3669              }
3670          }
3671  
3672          // Don't show the 'course' node if enrolled in this course.
3673          $coursecontext = context_course::instance($this->page->course->id);
3674          if (!is_enrolled($coursecontext, null, '', true)) {
3675              $courses = $this->page->navigation->get('courses');
3676              if (!$courses) {
3677                  // Courses node may not be present.
3678                  $courses = breadcrumb_navigation_node::create(
3679                      get_string('courses'),
3680                      new moodle_url('/course/index.php'),
3681                      self::TYPE_CONTAINER
3682                  );
3683              }
3684              $categories[] = $courses;
3685          }
3686  
3687          return $categories;
3688      }
3689  
3690      /**
3691       * Add a new breadcrumb_navigation_node to the navbar, overrides parent::add
3692       *
3693       * This function overrides {@link breadcrumb_navigation_node::add()} so that we can change
3694       * the way nodes get added to allow us to simply call add and have the node added to the
3695       * end of the navbar
3696       *
3697       * @param string $text
3698       * @param string|moodle_url|action_link $action An action to associate with this node.
3699       * @param int $type One of navigation_node::TYPE_*
3700       * @param string $shorttext
3701       * @param string|int $key A key to identify this node with. Key + type is unique to a parent.
3702       * @param pix_icon $icon An optional icon to use for this node.
3703       * @return navigation_node
3704       */
3705      public function add($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
3706          if ($this->content !== null) {
3707              debugging('Nav bar items must be printed before $OUTPUT->header() has been called', DEBUG_DEVELOPER);
3708          }
3709  
3710          // Properties array used when creating the new navigation node
3711          $itemarray = array(
3712              'text' => $text,
3713              'type' => $type
3714          );
3715          // Set the action if one was provided
3716          if ($action!==null) {
3717              $itemarray['action'] = $action;
3718          }
3719          // Set the shorttext if one was provided
3720          if ($shorttext!==null) {
3721              $itemarray['shorttext'] = $shorttext;
3722          }
3723          // Set the icon if one was provided
3724          if ($icon!==null) {
3725              $itemarray['icon'] = $icon;
3726          }
3727          // Default the key to the number of children if not provided
3728          if ($key === null) {
3729              $key = count($this->children);
3730          }
3731          // Set the key
3732          $itemarray['key'] = $key;
3733          // Set the parent to this node
3734          $itemarray['parent'] = $this;
3735          // Add the child using the navigation_node_collections add method
3736          $this->children[] = new breadcrumb_navigation_node($itemarray);
3737          return $this;
3738      }
3739  
3740      /**
3741       * Prepends a new navigation_node to the start of the navbar
3742       *
3743       * @param string $text
3744       * @param string|moodle_url|action_link $action An action to associate with this node.
3745       * @param int $type One of navigation_node::TYPE_*
3746       * @param string $shorttext
3747       * @param string|int $key A key to identify this node with. Key + type is unique to a parent.
3748       * @param pix_icon $icon An optional icon to use for this node.
3749       * @return navigation_node
3750       */
3751      public function prepend($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
3752          if ($this->content !== null) {
3753              debugging('Nav bar items must be printed before $OUTPUT->header() has been called', DEBUG_DEVELOPER);
3754          }
3755          // Properties array used when creating the new navigation node.
3756          $itemarray = array(
3757              'text' => $text,
3758              'type' => $type
3759          );
3760          // Set the action if one was provided.
3761          if ($action!==null) {
3762              $itemarray['action'] = $action;
3763          }
3764          // Set the shorttext if one was provided.
3765          if ($shorttext!==null) {
3766              $itemarray['shorttext'] = $shorttext;
3767          }
3768          // Set the icon if one was provided.
3769          if ($icon!==null) {
3770              $itemarray['icon'] = $icon;
3771          }
3772          // Default the key to the number of children if not provided.
3773          if ($key === null) {
3774              $key = count($this->children);
3775          }
3776          // Set the key.
3777          $itemarray['key'] = $key;
3778          // Set the parent to this node.
3779          $itemarray['parent'] = $this;
3780          // Add the child node to the prepend list.
3781          $this->prependchildren[] = new breadcrumb_navigation_node($itemarray);
3782          return $this;
3783      }
3784  }
3785  
3786  /**
3787   * Subclass of navigation_node allowing different rendering for the breadcrumbs
3788   * in particular adding extra metadata for search engine robots to leverage.
3789   *
3790   * @package   core
3791   * @category  navigation
3792   * @copyright 2015 Brendan Heywood
3793   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3794   */
3795  class breadcrumb_navigation_node extends navigation_node {
3796  
3797      /** @var $last boolean A flag indicating this is the last item in the list of breadcrumbs. */
3798      private $last = false;
3799  
3800      /**
3801       * A proxy constructor
3802       *
3803       * @param mixed $navnode A navigation_node or an array
3804       */
3805      public function __construct($navnode) {
3806          if (is_array($navnode)) {
3807              parent::__construct($navnode);
3808          } else if ($navnode instanceof navigation_node) {
3809  
3810              // Just clone everything.
3811              $objvalues = get_object_vars($navnode);
3812              foreach ($objvalues as $key => $value) {
3813                   $this->$key = $value;
3814              }
3815          } else {
3816              throw new coding_exception('Not a valid breadcrumb_navigation_node');
3817          }
3818      }
3819  
3820      /**
3821       * Getter for "last"
3822       * @return boolean
3823       */
3824      public function is_last() {
3825          return $this->last;
3826      }
3827  
3828      /**
3829       * Setter for "last"
3830       * @param $val boolean
3831       */
3832      public function set_last($val) {
3833          $this->last = $val;
3834      }
3835  }
3836  
3837  /**
3838   * Subclass of navigation_node allowing different rendering for the flat navigation
3839   * in particular allowing dividers and indents.
3840   *
3841   * @package   core
3842   * @category  navigation
3843   * @copyright 2016 Damyon Wiese
3844   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3845   */
3846  class flat_navigation_node extends navigation_node {
3847  
3848      /** @var $indent integer The indent level */
3849      private $indent = 0;
3850  
3851      /** @var $showdivider bool Show a divider before this element */
3852      private $showdivider = false;
3853  
3854      /** @var $collectionlabel string Label for a group of nodes */
3855      private $collectionlabel = '';
3856  
3857      /**
3858       * A proxy constructor
3859       *
3860       * @param mixed $navnode A navigation_node or an array
3861       */
3862      public function __construct($navnode, $indent) {
3863          if (is_array($navnode)) {
3864              parent::__construct($navnode);
3865          } else if ($navnode instanceof navigation_node) {
3866  
3867              // Just clone everything.
3868              $objvalues = get_object_vars($navnode);
3869              foreach ($objvalues as $key => $value) {
3870                   $this->$key = $value;
3871              }
3872          } else {
3873              throw new coding_exception('Not a valid flat_navigation_node');
3874          }
3875          $this->indent = $indent;
3876      }
3877  
3878      /**
3879       * Setter, a label is required for a flat navigation node that shows a divider.
3880       *
3881       * @param string $label
3882       */
3883      public function set_collectionlabel($label) {
3884          $this->collectionlabel = $label;
3885      }
3886  
3887      /**
3888       * Getter, get the label for this flat_navigation node, or it's parent if it doesn't have one.
3889       *
3890       * @return string
3891       */
3892      public function get_collectionlabel() {
3893          if (!empty($this->collectionlabel)) {
3894              return $this->collectionlabel;
3895          }
3896          if ($this->parent && ($this->parent instanceof flat_navigation_node || $this->parent instanceof flat_navigation)) {
3897              return $this->parent->get_collectionlabel();
3898          }
3899          debugging('Navigation region requires a label', DEBUG_DEVELOPER);
3900          return '';
3901      }
3902  
3903      /**
3904       * Does this node represent a course section link.
3905       * @return boolean
3906       */
3907      public function is_section() {
3908          return $this->type == navigation_node::TYPE_SECTION;
3909      }
3910  
3911      /**
3912       * In flat navigation - sections are active if we are looking at activities in the section.
3913       * @return boolean
3914       */
3915      public function isactive() {
3916          global $PAGE;
3917  
3918          if ($this->is_section()) {
3919              $active = $PAGE->navigation->find_active_node();
3920              while ($active = $active->parent) {
3921                  if ($active->key == $this->key && $active->type == $this->type) {
3922                      return true;
3923                  }
3924              }
3925          }
3926          return $this->isactive;
3927      }
3928  
3929      /**
3930       * Getter for "showdivider"
3931       * @return boolean
3932       */
3933      public function showdivider() {
3934          return $this->showdivider;
3935      }
3936  
3937      /**
3938       * Setter for "showdivider"
3939       * @param $val boolean
3940       * @param $label string Label for the group of nodes
3941       */
3942      public function set_showdivider($val, $label = '') {
3943          $this->showdivider = $val;
3944          if ($this->showdivider && empty($label)) {
3945              debugging('Navigation region requires a label', DEBUG_DEVELOPER);
3946          } else {
3947              $this->set_collectionlabel($label);
3948          }
3949      }
3950  
3951      /**
3952       * Getter for "indent"
3953       * @return boolean
3954       */
3955      public function get_indent() {
3956          return $this->indent;
3957      }
3958  
3959      /**
3960       * Setter for "indent"
3961       * @param $val boolean
3962       */
3963      public function set_indent($val) {
3964          $this->indent = $val;
3965      }
3966  }
3967  
3968  /**
3969   * Class used to generate a collection of navigation nodes most closely related
3970   * to the current page.
3971   *
3972   * @package core
3973   * @copyright 2016 Damyon Wiese
3974   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3975   */
3976  class flat_navigation extends navigation_node_collection {
3977      /** @var moodle_page the moodle page that the navigation belongs to */
3978      protected $page;
3979  
3980      /**
3981       * Constructor.
3982       *
3983       * @param moodle_page $page
3984       */
3985      public function __construct(moodle_page &$page) {
3986          if (during_initial_install()) {
3987              return false;
3988          }
3989          $this->page = $page;
3990      }
3991  
3992      /**
3993       * Build the list of navigation nodes based on the current navigation and settings trees.
3994       *
3995       */
3996      public function initialise() {
3997          global $PAGE, $USER, $OUTPUT, $CFG;
3998          if (during_initial_install()) {
3999              return;
4000          }
4001  
4002          $current = false;
4003  
4004          $course = $PAGE->course;
4005  
4006          $this->page->navigation->initialise();
4007  
4008          // First walk the nav tree looking for "flat_navigation" nodes.
4009          if ($course->id > 1) {
4010              // It's a real course.
4011              $url = new moodle_url('/course/view.php', array('id' => $course->id));
4012  
4013              $coursecontext = context_course::instance($course->id, MUST_EXIST);
4014              // This is the name that will be shown for the course.
4015              $coursename = empty($CFG->navshowfullcoursenames) ?
4016                  format_string($course->shortname, true, array('context' => $coursecontext)) :
4017                  format_string($course->fullname, true, array('context' => $coursecontext));
4018  
4019              $flat = new flat_navigation_node(navigation_node::create($coursename, $url), 0);
4020              $flat->set_collectionlabel($coursename);
4021              $flat->key = 'coursehome';
4022              $flat->icon = new pix_icon('i/course', '');
4023  
4024              $courseformat = course_get_format($course);
4025              $coursenode = $PAGE->navigation->find_active_node();
4026              $targettype = navigation_node::TYPE_COURSE;
4027  
4028              // Single activity format has no course node - the course node is swapped for the activity node.
4029              if (!$courseformat->has_view_page()) {
4030                  $targettype = navigation_node::TYPE_ACTIVITY;
4031              }
4032  
4033              while (!empty($coursenode) && ($coursenode->type != $targettype)) {
4034                  $coursenode = $coursenode->parent;
4035              }
4036              // There is one very strange page in mod/feedback/view.php which thinks it is both site and course
4037              // context at the same time. That page is broken but we need to handle it (hence the SITEID).
4038              if ($coursenode && $coursenode->key != SITEID) {
4039                  $this->add($flat);
4040                  foreach ($coursenode->children as $child) {
4041                      if ($child->action) {
4042                          $flat = new flat_navigation_node($child, 0);
4043                          $this->add($flat);
4044                      }
4045                  }
4046              }
4047  
4048              $this->page->navigation->build_flat_navigation_list($this, true, get_string('site'));
4049          } else {
4050              $this->page->navigation->build_flat_navigation_list($this, false, get_string('site'));
4051          }
4052  
4053          $admin = $PAGE->settingsnav->find('siteadministration', navigation_node::TYPE_SITE_ADMIN);
4054          if (!$admin) {
4055              // Try again - crazy nav tree!
4056              $admin = $PAGE->settingsnav->find('root', navigation_node::TYPE_SITE_ADMIN);
4057          }
4058          if ($admin) {
4059              $flat = new flat_navigation_node($admin, 0);
4060              $flat->set_showdivider(true, get_string('sitesettings'));
4061              $flat->key = 'sitesettings';
4062              $flat->icon = new pix_icon('t/preferences', '');
4063              $this->add($flat);
4064          }
4065  
4066          // Add-a-block in editing mode.
4067          if (isset($this->page->theme->addblockposition) &&
4068                  $this->page->theme->addblockposition == BLOCK_ADDBLOCK_POSITION_FLATNAV &&
4069                  $PAGE->user_is_editing() && $PAGE->user_can_edit_blocks() &&
4070                  ($addable = $PAGE->blocks->get_addable_blocks())) {
4071              $url = new moodle_url($PAGE->url, ['bui_addblock' => '', 'sesskey' => sesskey()]);
4072              $addablock = navigation_node::create(get_string('addblock'), $url);
4073              $flat = new flat_navigation_node($addablock, 0);
4074              $flat->set_showdivider(true, get_string('blocksaddedit'));
4075              $flat->key = 'addblock';
4076              $flat->icon = new pix_icon('i/addblock', '');
4077              $this->add($flat);
4078              $blocks = [];
4079              foreach ($addable as $block) {
4080                  $blocks[] = $block->name;
4081              }
4082              $params = array('blocks' => $blocks, 'url' => '?' . $url->get_query_string(false));
4083              $PAGE->requires->js_call_amd('core/addblockmodal', 'init', array($params));
4084          }
4085      }
4086  
4087  
4088      /**
4089       * Override the parent so we can set a label for this collection if it has not been set yet.
4090       *
4091       * @param navigation_node $node Node to add
4092       * @param string $beforekey If specified, adds before a node with this key,
4093       *   otherwise adds at end
4094       * @return navigation_node Added node
4095       */
4096      public function add(navigation_node $node, $beforekey=null) {
4097          $result = parent::add($node, $beforekey);
4098          // Extend the parent to get a name for the collection of nodes if required.
4099          if (empty($this->collectionlabel)) {
4100              if ($node instanceof flat_navigation_node) {
4101                  $this->set_collectionlabel($node->get_collectionlabel());
4102              }
4103          }
4104  
4105          return $result;
4106      }
4107  }
4108  
4109  /**
4110   * Class used to manage the settings option for the current page
4111   *
4112   * This class is used to manage the settings options in a tree format (recursively)
4113   * and was created initially for use with the settings blocks.
4114   *
4115   * @package   core
4116   * @category  navigation
4117   * @copyright 2009 Sam Hemelryk
4118   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
4119   */
4120  class settings_navigation extends navigation_node {
4121      /** @var stdClass the current context */
4122      protected $context;
4123      /** @var moodle_page the moodle page that the navigation belongs to */
4124      protected $page;
4125      /** @var string contains administration section navigation_nodes */
4126      protected $adminsection;
4127      /** @var bool A switch to see if the navigation node is initialised */
4128      protected $initialised = false;
4129      /** @var array An array of users that the nodes can extend for. */
4130      protected $userstoextendfor = array();
4131      /** @var navigation_cache **/
4132      protected $cache;
4133  
4134      /**
4135       * Sets up the object with basic settings and preparse it for use
4136       *
4137       * @param moodle_page $page
4138       */
4139      public function __construct(moodle_page &$page) {
4140          if (during_initial_install()) {
4141              return false;
4142          }
4143          $this->page = $page;
4144          // Initialise the main navigation. It is most important that this is done
4145          // before we try anything
4146          $this->page->navigation->initialise();
4147          // Initialise the navigation cache
4148          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
4149          $this->children = new navigation_node_collection();
4150      }
4151  
4152      /**
4153       * Initialise the settings navigation based on the current context
4154       *
4155       * This function initialises the settings navigation tree for a given context
4156       * by calling supporting functions to generate major parts of the tree.
4157       *
4158       */
4159      public function initialise() {
4160          global $DB, $SESSION, $SITE;
4161  
4162          if (during_initial_install()) {
4163              return false;
4164          } else if ($this->initialised) {
4165              return true;
4166          }
4167          $this->id = 'settingsnav';
4168          $this->context = $this->page->context;
4169  
4170          $context = $this->context;
4171          if ($context->contextlevel == CONTEXT_BLOCK) {
4172              $this->load_block_settings();
4173              $context = $context->get_parent_context();
4174              $this->context = $context;
4175          }
4176          switch ($context->contextlevel) {
4177              case CONTEXT_SYSTEM:
4178                  if ($this->page->url->compare(new moodle_url('/admin/settings.php', array('section'=>'frontpagesettings')))) {
4179                      $this->load_front_page_settings(($context->id == $this->context->id));
4180                  }
4181                  break;
4182              case CONTEXT_COURSECAT:
4183                  $this->load_category_settings();
4184                  break;
4185              case CONTEXT_COURSE:
4186                  if ($this->page->course->id != $SITE->id) {
4187                      $this->load_course_settings(($context->id == $this->context->id));
4188                  } else {
4189                      $this->load_front_page_settings(($context->id == $this->context->id));
4190                  }
4191                  break;
4192              case CONTEXT_MODULE:
4193                  $this->load_module_settings();
4194                  $this->load_course_settings();
4195                  break;
4196              case CONTEXT_USER:
4197                  if ($this->page->course->id != $SITE->id) {
4198                      $this->load_course_settings();
4199                  }
4200                  break;
4201          }
4202  
4203          $usersettings = $this->load_user_settings($this->page->course->id);
4204  
4205          $adminsettings = false;
4206          if (isloggedin() && !isguestuser() && (!isset($SESSION->load_navigation_admin) || $SESSION->load_navigation_admin)) {
4207              $isadminpage = $this->is_admin_tree_needed();
4208  
4209              if (has_capability('moodle/site:configview', context_system::instance())) {
4210                  if (has_capability('moodle/site:config', context_system::instance())) {
4211                      // Make sure this works even if config capability changes on the fly
4212                      // and also make it fast for admin right after login.
4213                      $SESSION->load_navigation_admin = 1;
4214                      if ($isadminpage) {
4215                          $adminsettings = $this->load_administration_settings();
4216                      }
4217  
4218                  } else if (!isset($SESSION->load_navigation_admin)) {
4219                      $adminsettings = $this->load_administration_settings();
4220                      $SESSION->load_navigation_admin = (int)($adminsettings->children->count() > 0);
4221  
4222                  } else if ($SESSION->load_navigation_admin) {
4223                      if ($isadminpage) {
4224                          $adminsettings = $this->load_administration_settings();
4225                      }
4226                  }
4227  
4228                  // Print empty navigation node, if needed.
4229                  if ($SESSION->load_navigation_admin && !$isadminpage) {
4230                      if ($adminsettings) {
4231                          // Do not print settings tree on pages that do not need it, this helps with performance.
4232                          $adminsettings->remove();
4233                          $adminsettings = false;
4234                      }
4235                      $siteadminnode = $this->add(get_string('administrationsite'), new moodle_url('/admin/search.php'),
4236                              self::TYPE_SITE_ADMIN, null, 'siteadministration');
4237                      $siteadminnode->id = 'expandable_branch_' . $siteadminnode->type . '_' .
4238                              clean_param($siteadminnode->key, PARAM_ALPHANUMEXT);
4239                      $siteadminnode->requiresajaxloading = 'true';
4240                  }
4241              }
4242          }
4243  
4244          if ($context->contextlevel == CONTEXT_SYSTEM && $adminsettings) {
4245              $adminsettings->force_open();
4246          } else if ($context->contextlevel == CONTEXT_USER && $usersettings) {
4247              $usersettings->force_open();
4248          }
4249  
4250          // At this point we give any local plugins the ability to extend/tinker with the navigation settings.
4251          $this->load_local_plugin_settings();
4252  
4253          foreach ($this->children as $key=>$node) {
4254              if ($node->nodetype == self::NODETYPE_BRANCH && $node->children->count() == 0) {
4255                  // Site administration is shown as link.
4256                  if (!empty($SESSION->load_navigation_admin) && ($node->type === self::TYPE_SITE_ADMIN)) {
4257                      continue;
4258                  }
4259                  $node->remove();
4260              }
4261          }
4262          $this->initialised = true;
4263      }
4264      /**
4265       * Override the parent function so that we can add preceeding hr's and set a
4266       * root node class against all first level element
4267       *
4268       * It does this by first calling the parent's add method {@link navigation_node::add()}
4269       * and then proceeds to use the key to set class and hr
4270       *
4271       * @param string $text text to be used for the link.
4272       * @param string|moodle_url $url url for the new node
4273       * @param int $type the type of node navigation_node::TYPE_*
4274       * @param string $shorttext
4275       * @param string|int $key a key to access the node by.
4276       * @param pix_icon $icon An icon that appears next to the node.
4277       * @return navigation_node with the new node added to it.
4278       */
4279      public function add($text, $url=null, $type=null, $shorttext=null, $key=null, pix_icon $icon=null) {
4280          $node = parent::add($text, $url, $type, $shorttext, $key, $icon);
4281          $node->add_class('root_node');
4282          return $node;
4283      }
4284  
4285      /**
4286       * This function allows the user to add something to the start of the settings
4287       * navigation, which means it will be at the top of the settings navigation block
4288       *
4289       * @param string $text text to be used for the link.
4290       * @param string|moodle_url $url url for the new node
4291       * @param int $type the type of node navigation_node::TYPE_*
4292       * @param string $shorttext
4293       * @param string|int $key a key to access the node by.
4294       * @param pix_icon $icon An icon that appears next to the node.
4295       * @return navigation_node $node with the new node added to it.
4296       */
4297      public function prepend($text, $url=null, $type=null, $shorttext=null, $key=null, pix_icon $icon=null) {
4298          $children = $this->children;
4299          $childrenclass = get_class($children);
4300          $this->children = new $childrenclass;
4301          $node = $this->add($text, $url, $type, $shorttext, $key, $icon);
4302          foreach ($children as $child) {
4303              $this->children->add($child);
4304          }
4305          return $node;
4306      }
4307  
4308      /**
4309       * Does this page require loading of full admin tree or is
4310       * it enough rely on AJAX?
4311       *
4312       * @return bool
4313       */
4314      protected function is_admin_tree_needed() {
4315          if (self::$loadadmintree) {
4316              // Usually external admin page or settings page.
4317              return true;
4318          }
4319  
4320          if ($this->page->pagelayout === 'admin' or strpos($this->page->pagetype, 'admin-') === 0) {
4321              // Admin settings tree is intended for system level settings and management only, use navigation for the rest!
4322              if ($this->page->context->contextlevel != CONTEXT_SYSTEM) {
4323                  return false;
4324              }
4325              return true;
4326          }
4327  
4328          return false;
4329      }
4330  
4331      /**
4332       * Load the site administration tree
4333       *
4334       * This function loads the site administration tree by using the lib/adminlib library functions
4335       *
4336       * @param navigation_node $referencebranch A reference to a branch in the settings
4337       *      navigation tree
4338       * @param part_of_admin_tree $adminbranch The branch to add, if null generate the admin
4339       *      tree and start at the beginning
4340       * @return mixed A key to access the admin tree by
4341       */
4342      protected function load_administration_settings(navigation_node $referencebranch=null, part_of_admin_tree $adminbranch=null) {
4343          global $CFG;
4344  
4345          // Check if we are just starting to generate this navigation.
4346          if ($referencebranch === null) {
4347  
4348              // Require the admin lib then get an admin structure
4349              if (!function_exists('admin_get_root')) {
4350                  require_once($CFG->dirroot.'/lib/adminlib.php');
4351              }
4352              $adminroot = admin_get_root(false, false);
4353              // This is the active section identifier
4354              $this->adminsection = $this->page->url->param('section');
4355  
4356              // Disable the navigation from automatically finding the active node
4357              navigation_node::$autofindactive = false;
4358              $referencebranch = $this->add(get_string('administrationsite'), '/admin/search.php', self::TYPE_SITE_ADMIN, null, 'root');
4359              foreach ($adminroot->children as $adminbranch) {
4360                  $this->load_administration_settings($referencebranch, $adminbranch);
4361              }
4362              navigation_node::$autofindactive = true;
4363  
4364              // Use the admin structure to locate the active page
4365              if (!$this->contains_active_node() && $current = $adminroot->locate($this->adminsection, true)) {
4366                  $currentnode = $this;
4367                  while (($pathkey = array_pop($current->path))!==null && $currentnode) {
4368                      $currentnode = $currentnode->get($pathkey);
4369                  }
4370                  if ($currentnode) {
4371                      $currentnode->make_active();
4372                  }
4373              } else {
4374                  $this->scan_for_active_node($referencebranch);
4375              }
4376              return $referencebranch;
4377          } else if ($adminbranch->check_access()) {
4378              // We have a reference branch that we can access and is not hidden `hurrah`
4379              // Now we need to display it and any children it may have
4380              $url = null;
4381              $icon = null;
4382              if ($adminbranch instanceof admin_settingpage) {
4383                  $url = new moodle_url('/'.$CFG->admin.'/settings.php', array('section'=>$adminbranch->name));
4384              } else if ($adminbranch instanceof admin_externalpage) {
4385                  $url = $adminbranch->url;
4386              } else if (!empty($CFG->linkadmincategories) && $adminbranch instanceof admin_category) {
4387                  $url = new moodle_url('/'.$CFG->admin.'/category.php', array('category' => $adminbranch->name));
4388              }
4389  
4390              // Add the branch
4391              $reference = $referencebranch->add($adminbranch->visiblename, $url, self::TYPE_SETTING, null, $adminbranch->name, $icon);
4392  
4393              if ($adminbranch->is_hidden()) {
4394                  if (($adminbranch instanceof admin_externalpage || $adminbranch instanceof admin_settingpage) && $adminbranch->name == $this->adminsection) {
4395                      $reference->add_class('hidden');
4396                  } else {
4397                      $reference->display = false;
4398                  }
4399              }
4400  
4401              // Check if we are generating the admin notifications and whether notificiations exist
4402              if ($adminbranch->name === 'adminnotifications' && admin_critical_warnings_present()) {
4403                  $reference->add_class('criticalnotification');
4404              }
4405              // Check if this branch has children
4406              if ($reference && isset($adminbranch->children) && is_array($adminbranch->children) && count($adminbranch->children)>0) {
4407                  foreach ($adminbranch->children as $branch) {
4408                      // Generate the child branches as well now using this branch as the reference
4409                      $this->load_administration_settings($reference, $branch);
4410                  }
4411              } else {
4412                  $reference->icon = new pix_icon('i/settings', '');
4413              }
4414          }
4415      }
4416  
4417      /**
4418       * This function recursivily scans nodes until it finds the active node or there
4419       * are no more nodes.
4420       * @param navigation_node $node
4421       */
4422      protected function scan_for_active_node(navigation_node $node) {
4423          if (!$node->check_if_active() && $node->children->count()>0) {
4424              foreach ($node->children as &$child) {
4425                  $this->scan_for_active_node($child);
4426              }
4427          }
4428      }
4429  
4430      /**
4431       * Gets a navigation node given an array of keys that represent the path to
4432       * the desired node.
4433       *
4434       * @param array $path
4435       * @return navigation_node|false
4436       */
4437      protected function get_by_path(array $path) {
4438          $node = $this->get(array_shift($path));
4439          foreach ($path as $key) {
4440              $node->get($key);
4441          }
4442          return $node;
4443      }
4444  
4445      /**
4446       * This function loads the course settings that are available for the user
4447       *
4448       * @param bool $forceopen If set to true the course node will be forced open
4449       * @return navigation_node|false
4450       */
4451      protected function load_course_settings($forceopen = false) {
4452          global $CFG;
4453          require_once($CFG->dirroot . '/course/lib.php');
4454  
4455          $course = $this->page->course;
4456          $coursecontext = context_course::instance($course->id);
4457          $adminoptions = course_get_user_administration_options($course, $coursecontext);
4458  
4459          // note: do not test if enrolled or viewing here because we need the enrol link in Course administration section
4460  
4461          $coursenode = $this->add(get_string('courseadministration'), null, self::TYPE_COURSE, null, 'courseadmin');
4462          if ($forceopen) {
4463              $coursenode->force_open();
4464          }
4465  
4466  
4467          if ($adminoptions->update) {
4468              // Add the course settings link
4469              $url = new moodle_url('/course/edit.php', array('id'=>$course->id));
4470              $coursenode->add(get_string('editsettings'), $url, self::TYPE_SETTING, null, 'editsettings', new pix_icon('i/settings', ''));
4471          }
4472  
4473          if ($adminoptions->editcompletion) {
4474              // Add the course completion settings link
4475              $url = new moodle_url('/course/completion.php', array('id' => $course->id));
4476              $coursenode->add(get_string('coursecompletion', 'completion'), $url, self::TYPE_SETTING, null, null,
4477                               new pix_icon('i/settings', ''));
4478          }
4479  
4480          if (!$adminoptions->update && $adminoptions->tags) {
4481              $url = new moodle_url('/course/tags.php', array('id' => $course->id));
4482              $coursenode->add(get_string('coursetags', 'tag'), $url, self::TYPE_SETTING, null, 'coursetags', new pix_icon('i/settings', ''));
4483          }
4484  
4485          // add enrol nodes
4486          enrol_add_course_navigation($coursenode, $course);
4487  
4488          // Manage filters
4489          if ($adminoptions->filters) {
4490              $url = new moodle_url('/filter/manage.php', array('contextid'=>$coursecontext->id));
4491              $coursenode->add(get_string('filters', 'admin'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/filter', ''));
4492          }
4493  
4494          // View course reports.
4495          if ($adminoptions->reports) {
4496              $reportnav = $coursenode->add(get_string('reports'), null, self::TYPE_CONTAINER, null, 'coursereports',
4497                      new pix_icon('i/stats', ''));
4498              $coursereports = core_component::get_plugin_list('coursereport');
4499              foreach ($coursereports as $report => $dir) {
4500                  $libfile = $CFG->dirroot.'/course/report/'.$report.'/lib.php';
4501                  if (file_exists($libfile)) {
4502                      require_once($libfile);
4503                      $reportfunction = $report.'_report_extend_navigation';
4504                      if (function_exists($report.'_report_extend_navigation')) {
4505                          $reportfunction($reportnav, $course, $coursecontext);
4506                      }
4507                  }
4508              }
4509  
4510              $reports = get_plugin_list_with_function('report', 'extend_navigation_course', 'lib.php');
4511              foreach ($reports as $reportfunction) {
4512                  $reportfunction($reportnav, $course, $coursecontext);
4513              }
4514          }
4515  
4516          // Check if we can view the gradebook's setup page.
4517          if ($adminoptions->gradebook) {
4518              $url = new moodle_url('/grade/edit/tree/index.php', array('id' => $course->id));
4519              $coursenode->add(get_string('gradebooksetup', 'grades'), $url, self::TYPE_SETTING,
4520                  null, 'gradebooksetup', new pix_icon('i/settings', ''));
4521          }
4522  
4523          // Add the context locking node.
4524          $this->add_context_locking_node($coursenode, $coursecontext);
4525  
4526          //  Add outcome if permitted
4527          if ($adminoptions->outcomes) {
4528              $url = new moodle_url('/grade/edit/outcome/course.php', array('id'=>$course->id));
4529              $coursenode->add(get_string('outcomes', 'grades'), $url, self::TYPE_SETTING, null, 'outcomes', new pix_icon('i/outcomes', ''));
4530          }
4531  
4532          //Add badges navigation
4533          if ($adminoptions->badges) {
4534              require_once($CFG->libdir .'/badgeslib.php');
4535              badges_add_course_navigation($coursenode, $course);
4536          }
4537  
4538          // Backup this course
4539          if ($adminoptions->backup) {
4540              $url = new moodle_url('/backup/backup.php', array('id'=>$course->id));
4541              $coursenode->add(get_string('backup'), $url, self::TYPE_SETTING, null, 'backup', new pix_icon('i/backup', ''));
4542          }
4543  
4544          // Restore to this course
4545          if ($adminoptions->restore) {
4546              $url = new moodle_url('/backup/restorefile.php', array('contextid'=>$coursecontext->id));
4547              $coursenode->add(get_string('restore'), $url, self::TYPE_SETTING, null, 'restore', new pix_icon('i/restore', ''));
4548          }
4549  
4550          // Import data from other courses
4551          if ($adminoptions->import) {
4552              $url = new moodle_url('/backup/import.php', array('id'=>$course->id));
4553              $coursenode->add(get_string('import'), $url, self::TYPE_SETTING, null, 'import', new pix_icon('i/import', ''));
4554          }
4555  
4556          // Copy this course.
4557          if ($adminoptions->copy) {
4558              $url = new moodle_url('/backup/copy.php', array('id' => $course->id));
4559              $coursenode->add(get_string('copycourse'), $url, self::TYPE_SETTING, null, 'copy', new pix_icon('t/copy', ''));
4560          }
4561  
4562          // Reset this course
4563          if ($adminoptions->reset) {
4564              $url = new moodle_url('/course/reset.php', array('id'=>$course->id));
4565              $coursenode->add(get_string('reset'), $url, self::TYPE_SETTING, null, 'reset', new pix_icon('i/return', ''));
4566          }
4567  
4568          // Questions
4569          require_once($CFG->libdir . '/questionlib.php');
4570          question_extend_settings_navigation($coursenode, $coursecontext)->trim_if_empty();
4571  
4572          if ($adminoptions->update) {
4573              // Repository Instances
4574              if (!$this->cache->cached('contexthasrepos'.$coursecontext->id)) {
4575                  require_once($CFG->dirroot . '/repository/lib.php');
4576                  $editabletypes = repository::get_editable_types($coursecontext);
4577                  $haseditabletypes = !empty($editabletypes);
4578                  unset($editabletypes);
4579                  $this->cache->set('contexthasrepos'.$coursecontext->id, $haseditabletypes);
4580              } else {
4581                  $haseditabletypes = $this->cache->{'contexthasrepos'.$coursecontext->id};
4582              }
4583              if ($haseditabletypes) {
4584                  $url = new moodle_url('/repository/manage_instances.php', array('contextid' => $coursecontext->id));
4585                  $coursenode->add(get_string('repositories'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/repository', ''));
4586              }
4587          }
4588  
4589          // Manage files
4590          if ($adminoptions->files) {
4591              // hidden in new courses and courses where legacy files were turned off
4592              $url = new moodle_url('/files/index.php', array('contextid'=>$coursecontext->id));
4593              $coursenode->add(get_string('courselegacyfiles'), $url, self::TYPE_SETTING, null, 'coursefiles', new pix_icon('i/folder', ''));
4594  
4595          }
4596  
4597          // Let plugins hook into course navigation.
4598          $pluginsfunction = get_plugins_with_function('extend_navigation_course', 'lib.php');
4599          foreach ($pluginsfunction as $plugintype => $plugins) {
4600              // Ignore the report plugin as it was already loaded above.
4601              if ($plugintype == 'report') {
4602                  continue;
4603              }
4604              foreach ($plugins as $pluginfunction) {
4605                  $pluginfunction($coursenode, $course, $coursecontext);
4606              }
4607          }
4608  
4609          // Return we are done
4610          return $coursenode;
4611      }
4612  
4613      /**
4614       * This function calls the module function to inject module settings into the
4615       * settings navigation tree.
4616       *
4617       * This only gets called if there is a corrosponding function in the modules
4618       * lib file.
4619       *
4620       * For examples mod/forum/lib.php {@link forum_extend_settings_navigation()}
4621       *
4622       * @return navigation_node|false
4623       */
4624      protected function load_module_settings() {
4625          global $CFG;
4626  
4627          if (!$this->page->cm && $this->context->contextlevel == CONTEXT_MODULE && $this->context->instanceid) {
4628              $cm = get_coursemodule_from_id(false, $this->context->instanceid, 0, false, MUST_EXIST);
4629              $this->page->set_cm($cm, $this->page->course);
4630          }
4631  
4632          $file = $CFG->dirroot.'/mod/'.$this->page->activityname.'/lib.php';
4633          if (file_exists($file)) {
4634              require_once($file);
4635          }
4636  
4637          $modulenode = $this->add(get_string('pluginadministration', $this->page->activityname), null, self::TYPE_SETTING, null, 'modulesettings');
4638          $modulenode->nodetype = navigation_node::NODETYPE_BRANCH;
4639          $modulenode->force_open();
4640  
4641          // Settings for the module
4642          if (has_capability('moodle/course:manageactivities', $this->page->cm->context)) {
4643              $url = new moodle_url('/course/modedit.php', array('update' => $this->page->cm->id, 'return' => 1));
4644              $modulenode->add(get_string('editsettings'), $url, navigation_node::TYPE_SETTING, null, 'modedit');
4645          }
4646          // Assign local roles
4647          if (count(get_assignable_roles($this->page->cm->context))>0) {
4648              $url = new moodle_url('/'.$CFG->admin.'/roles/assign.php', array('contextid'=>$this->page->cm->context->id));
4649              $modulenode->add(get_string('localroles', 'role'), $url, self::TYPE_SETTING, null, 'roleassign');
4650          }
4651          // Override roles
4652          if (has_capability('moodle/role:review', $this->page->cm->context) or count(get_overridable_roles($this->page->cm->context))>0) {
4653              $url = new moodle_url('/'.$CFG->admin.'/roles/permissions.php', array('contextid'=>$this->page->cm->context->id));
4654              $modulenode->add(get_string('permissions', 'role'), $url, self::TYPE_SETTING, null, 'roleoverride');
4655          }
4656          // Check role permissions
4657          if (has_any_capability(array('moodle/role:assign', 'moodle/role:safeoverride','moodle/role:override', 'moodle/role:assign'), $this->page->cm->context)) {
4658              $url = new moodle_url('/'.$CFG->admin.'/roles/check.php', array('contextid'=>$this->page->cm->context->id));
4659              $modulenode->add(get_string('checkpermissions', 'role'), $url, self::TYPE_SETTING, null, 'rolecheck');
4660          }
4661  
4662          // Add the context locking node.
4663          $this->add_context_locking_node($modulenode, $this->page->cm->context);
4664  
4665          // Manage filters
4666          if (has_capability('moodle/filter:manage', $this->page->cm->context) && count(filter_get_available_in_context($this->page->cm->context))>0) {
4667              $url = new moodle_url('/filter/manage.php', array('contextid'=>$this->page->cm->context->id));
4668              $modulenode->add(get_string('filters', 'admin'), $url, self::TYPE_SETTING, null, 'filtermanage');
4669          }
4670          // Add reports
4671          $reports = get_plugin_list_with_function('report', 'extend_navigation_module', 'lib.php');
4672          foreach ($reports as $reportfunction) {
4673              $reportfunction($modulenode, $this->page->cm);
4674          }
4675          // Add a backup link
4676          $featuresfunc = $this->page->activityname.'_supports';
4677          if (function_exists($featuresfunc) && $featuresfunc(FEATURE_BACKUP_MOODLE2) && has_capability('moodle/backup:backupactivity', $this->page->cm->context)) {
4678              $url = new moodle_url('/backup/backup.php', array('id'=>$this->page->cm->course, 'cm'=>$this->page->cm->id));
4679              $modulenode->add(get_string('backup'), $url, self::TYPE_SETTING, null, 'backup');
4680          }
4681  
4682          // Restore this activity
4683          $featuresfunc = $this->page->activityname.'_supports';
4684          if (function_exists($featuresfunc) && $featuresfunc(FEATURE_BACKUP_MOODLE2) && has_capability('moodle/restore:restoreactivity', $this->page->cm->context)) {
4685              $url = new moodle_url('/backup/restorefile.php', array('contextid'=>$this->page->cm->context->id));
4686              $modulenode->add(get_string('restore'), $url, self::TYPE_SETTING, null, 'restore');
4687          }
4688  
4689          // Allow the active advanced grading method plugin to append its settings
4690          $featuresfunc = $this->page->activityname.'_supports';
4691          if (function_exists($featuresfunc) && $featuresfunc(FEATURE_ADVANCED_GRADING) && has_capability('moodle/grade:managegradingforms', $this->page->cm->context)) {
4692              require_once($CFG->dirroot.'/grade/grading/lib.php');
4693              $gradingman = get_grading_manager($this->page->cm->context, 'mod_'.$this->page->activityname);
4694              $gradingman->extend_settings_navigation($this, $modulenode);
4695          }
4696  
4697          $function = $this->page->activityname.'_extend_settings_navigation';
4698          if (function_exists($function)) {
4699              $function($this, $modulenode);
4700          }
4701  
4702          // Remove the module node if there are no children.
4703          if ($modulenode->children->count() <= 0) {
4704              $modulenode->remove();
4705          }
4706  
4707          return $modulenode;
4708      }
4709  
4710      /**
4711       * Loads the user settings block of the settings nav
4712       *
4713       * This function is simply works out the userid and whether we need to load
4714       * just the current users profile settings, or the current user and the user the
4715       * current user is viewing.
4716       *
4717       * This function has some very ugly code to work out the user, if anyone has
4718       * any bright ideas please feel free to intervene.
4719       *
4720       * @param int $courseid The course id of the current course
4721       * @return navigation_node|false
4722       */
4723      protected function load_user_settings($courseid = SITEID) {
4724          global $USER, $CFG;
4725  
4726          if (isguestuser() || !isloggedin()) {
4727              return false;
4728          }
4729  
4730          $navusers = $this->page->navigation->get_extending_users();
4731  
4732          if (count($this->userstoextendfor) > 0 || count($navusers) > 0) {
4733              $usernode = null;
4734              foreach ($this->userstoextendfor as $userid) {
4735                  if ($userid == $USER->id) {
4736                      continue;
4737                  }
4738                  $node = $this->generate_user_settings($courseid, $userid, 'userviewingsettings');
4739                  if (is_null($usernode)) {
4740                      $usernode = $node;
4741                  }
4742              }
4743              foreach ($navusers as $user) {
4744                  if ($user->id == $USER->id) {
4745                      continue;
4746                  }
4747                  $node = $this->generate_user_settings($courseid, $user->id, 'userviewingsettings');
4748                  if (is_null($usernode)) {
4749                      $usernode = $node;
4750                  }
4751              }
4752              $this->generate_user_settings($courseid, $USER->id);
4753          } else {
4754              $usernode = $this->generate_user_settings($courseid, $USER->id);
4755          }
4756          return $usernode;
4757      }
4758  
4759      /**
4760       * Extends the settings navigation for the given user.
4761       *
4762       * Note: This method gets called automatically if you call
4763       * $PAGE->navigation->extend_for_user($userid)
4764       *
4765       * @param int $userid
4766       */
4767      public function extend_for_user($userid) {
4768          global $CFG;
4769  
4770          if (!in_array($userid, $this->userstoextendfor)) {
4771              $this->userstoextendfor[] = $userid;
4772              if ($this->initialised) {
4773                  $this->generate_user_settings($this->page->course->id, $userid, 'userviewingsettings');
4774                  $children = array();
4775                  foreach ($this->children as $child) {
4776                      $children[] = $child;
4777                  }
4778                  array_unshift($children, array_pop($children));
4779                  $this->children = new navigation_node_collection();
4780                  foreach ($children as $child) {
4781                      $this->children->add($child);
4782                  }
4783              }
4784          }
4785      }
4786  
4787      /**
4788       * This function gets called by {@link settings_navigation::load_user_settings()} and actually works out
4789       * what can be shown/done
4790       *
4791       * @param int $courseid The current course' id
4792       * @param int $userid The user id to load for
4793       * @param string $gstitle The string to pass to get_string for the branch title
4794       * @return navigation_node|false
4795       */
4796      protected function generate_user_settings($courseid, $userid, $gstitle='usercurrentsettings') {
4797          global $DB, $CFG, $USER, $SITE;
4798  
4799          if ($courseid != $SITE->id) {
4800              if (!empty($this->page->course->id) && $this->page->course->id == $courseid) {
4801                  $course = $this->page->course;
4802              } else {
4803                  $select = context_helper::get_preload_record_columns_sql('ctx');
4804                  $sql = "SELECT c.*, $select
4805                            FROM {course} c
4806                            JOIN {context} ctx ON c.id = ctx.instanceid
4807                           WHERE c.id = :courseid AND ctx.contextlevel = :contextlevel";
4808                  $params = array('courseid' => $courseid, 'contextlevel' => CONTEXT_COURSE);
4809                  $course = $DB->get_record_sql($sql, $params, MUST_EXIST);
4810                  context_helper::preload_from_record($course);
4811              }
4812          } else {
4813              $course = $SITE;
4814          }
4815  
4816          $coursecontext = context_course::instance($course->id);   // Course context
4817          $systemcontext   = context_system::instance();
4818          $currentuser = ($USER->id == $userid);
4819  
4820          if ($currentuser) {
4821              $user = $USER;
4822              $usercontext = context_user::instance($user->id);       // User context
4823          } else {
4824              $select = context_helper::get_preload_record_columns_sql('ctx');
4825              $sql = "SELECT u.*, $select
4826                        FROM {user} u
4827                        JOIN {context} ctx ON u.id = ctx.instanceid
4828                       WHERE u.id = :userid AND ctx.contextlevel = :contextlevel";
4829              $params = array('userid' => $userid, 'contextlevel' => CONTEXT_USER);
4830              $user = $DB->get_record_sql($sql, $params, IGNORE_MISSING);
4831              if (!$user) {
4832                  return false;
4833              }
4834              context_helper::preload_from_record($user);
4835  
4836              // Check that the user can view the profile
4837              $usercontext = context_user::instance($user->id); // User context
4838              $canviewuser = has_capability('moodle/user:viewdetails', $usercontext);
4839  
4840              if ($course->id == $SITE->id) {
4841                  if ($CFG->forceloginforprofiles && !has_coursecontact_role($user->id) && !$canviewuser) {  // Reduce possibility of "browsing" userbase at site level
4842                      // Teachers can browse and be browsed at site level. If not forceloginforprofiles, allow access (bug #4366)
4843                      return false;
4844                  }
4845              } else {
4846                  $canviewusercourse = has_capability('moodle/user:viewdetails', $coursecontext);
4847                  $userisenrolled = is_enrolled($coursecontext, $user->id, '', true);
4848                  if ((!$canviewusercourse && !$canviewuser) || !$userisenrolled) {
4849                      return false;
4850                  }
4851                  $canaccessallgroups = has_capability('moodle/site:accessallgroups', $coursecontext);
4852                  if (!$canaccessallgroups && groups_get_course_groupmode($course) == SEPARATEGROUPS && !$canviewuser) {
4853                      // If groups are in use, make sure we can see that group (MDL-45874). That does not apply to parents.
4854                      if ($courseid == $this->page->course->id) {
4855                          $mygroups = get_fast_modinfo($this->page->course)->groups;
4856                      } else {
4857                          $mygroups = groups_get_user_groups($courseid);
4858                      }
4859                      $usergroups = groups_get_user_groups($courseid, $userid);
4860                      if (!array_intersect_key($mygroups[0], $usergroups[0])) {
4861                          return false;
4862                      }
4863                  }
4864              }
4865          }
4866  
4867          $fullname = fullname($user, has_capability('moodle/site:viewfullnames', $this->page->context));
4868  
4869          $key = $gstitle;
4870          $prefurl = new moodle_url('/user/preferences.php');
4871          if ($gstitle != 'usercurrentsettings') {
4872              $key .= $userid;
4873              $prefurl->param('userid', $userid);
4874          }
4875  
4876          // Add a user setting branch.
4877          if ($gstitle == 'usercurrentsettings') {
4878              $dashboard = $this->add(get_string('myhome'), new moodle_url('/my/'), self::TYPE_CONTAINER, null, 'dashboard');
4879              // This should be set to false as we don't want to show this to the user. It's only for generating the correct
4880              // breadcrumb.
4881              $dashboard->display = false;
4882              if (get_home_page() == HOMEPAGE_MY) {
4883                  $dashboard->mainnavonly = true;
4884              }
4885  
4886              $iscurrentuser = ($user->id == $USER->id);
4887  
4888              $baseargs = array('id' => $user->id);
4889              if ($course->id != $SITE->id && !$iscurrentuser) {
4890                  $baseargs['course'] = $course->id;
4891                  $issitecourse = false;
4892              } else {
4893                  // Load all categories and get the context for the system.
4894                  $issitecourse = true;
4895              }
4896  
4897              // Add the user profile to the dashboard.
4898              $profilenode = $dashboard->add(get_string('profile'), new moodle_url('/user/profile.php',
4899                      array('id' => $user->id)), self::TYPE_SETTING, null, 'myprofile');
4900  
4901              if (!empty($CFG->navadduserpostslinks)) {
4902                  // Add nodes for forum posts and discussions if the user can view either or both
4903                  // There are no capability checks here as the content of the page is based
4904                  // purely on the forums the current user has access too.
4905                  $forumtab = $profilenode->add(get_string('forumposts', 'forum'));
4906                  $forumtab->add(get_string('posts', 'forum'), new moodle_url('/mod/forum/user.php', $baseargs), null, 'myposts');
4907                  $forumtab->add(get_string('discussions', 'forum'), new moodle_url('/mod/forum/user.php',
4908                          array_merge($baseargs, array('mode' => 'discussions'))), null, 'mydiscussions');
4909              }
4910  
4911              // Add blog nodes.
4912              if (!empty($CFG->enableblogs)) {
4913                  if (!$this->cache->cached('userblogoptions'.$user->id)) {
4914                      require_once($CFG->dirroot.'/blog/lib.php');
4915                      // Get all options for the user.
4916                      $options = blog_get_options_for_user($user);
4917                      $this->cache->set('userblogoptions'.$user->id, $options);
4918                  } else {
4919                      $options = $this->cache->{'userblogoptions'.$user->id};
4920                  }
4921  
4922                  if (count($options) > 0) {
4923                      $blogs = $profilenode->add(get_string('blogs', 'blog'), null, navigation_node::TYPE_CONTAINER);
4924                      foreach ($options as $type => $option) {
4925                          if ($type == "rss") {
4926                              $blogs->add($option['string'], $option['link'], self::TYPE_SETTING, null, null,
4927                                      new pix_icon('i/rss', ''));
4928                          } else {
4929                              $blogs->add($option['string'], $option['link'], self::TYPE_SETTING, null, 'blog' . $type);
4930                          }
4931                      }
4932                  }
4933              }
4934  
4935              // Add the messages link.
4936              // It is context based so can appear in the user's profile and in course participants information.
4937              if (!empty($CFG->messaging)) {
4938                  $messageargs = array('user1' => $USER->id);
4939                  if ($USER->id != $user->id) {
4940                      $messageargs['user2'] = $user->id;
4941                  }
4942                  $url = new moodle_url('/message/index.php', $messageargs);
4943                  $dashboard->add(get_string('messages', 'message'), $url, self::TYPE_SETTING, null, 'messages');
4944              }
4945  
4946              // Add the "My private files" link.
4947              // This link doesn't have a unique display for course context so only display it under the user's profile.
4948              if ($issitecourse && $iscurrentuser && has_capability('moodle/user:manageownfiles', $usercontext)) {
4949                  $url = new moodle_url('/user/files.php');
4950                  $dashboard->add(get_string('privatefiles'), $url, self::TYPE_SETTING, null, 'privatefiles');
4951              }
4952  
4953              // Add a node to view the users notes if permitted.
4954              if (!empty($CFG->enablenotes) &&
4955                      has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $coursecontext)) {
4956                  $url = new moodle_url('/notes/index.php', array('user' => $user->id));
4957                  if ($coursecontext->instanceid != SITEID) {
4958                      $url->param('course', $coursecontext->instanceid);
4959                  }
4960                  $profilenode->add(get_string('notes', 'notes'), $url);
4961              }
4962  
4963              // Show the grades node.
4964              if (($issitecourse && $iscurrentuser) || has_capability('moodle/user:viewdetails', $usercontext)) {
4965                  require_once($CFG->dirroot . '/user/lib.php');
4966                  // Set the grades node to link to the "Grades" page.
4967                  if ($course->id == SITEID) {
4968                      $url = user_mygrades_url($user->id, $course->id);
4969                  } else { // Otherwise we are in a course and should redirect to the user grade report (Activity report version).
4970                      $url = new moodle_url('/course/user.php', array('mode' => 'grade', 'id' => $course->id, 'user' => $user->id));
4971                  }
4972                  $dashboard->add(get_string('grades', 'grades'), $url, self::TYPE_SETTING, null, 'mygrades');
4973              }
4974  
4975              // Let plugins hook into user navigation.
4976              $pluginsfunction = get_plugins_with_function('extend_navigation_user', 'lib.php');
4977              foreach ($pluginsfunction as $plugintype => $plugins) {
4978                  if ($plugintype != 'report') {
4979                      foreach ($plugins as $pluginfunction) {
4980                          $pluginfunction($profilenode, $user, $usercontext, $course, $coursecontext);
4981                      }
4982                  }
4983              }
4984  
4985              $usersetting = navigation_node::create(get_string('preferences', 'moodle'), $prefurl, self::TYPE_CONTAINER, null, $key);
4986              $dashboard->add_node($usersetting);
4987          } else {
4988              $usersetting = $this->add(get_string('preferences', 'moodle'), $prefurl, self::TYPE_CONTAINER, null, $key);
4989              $usersetting->display = false;
4990          }
4991          $usersetting->id = 'usersettings';
4992  
4993          // Check if the user has been deleted.
4994          if ($user->deleted) {
4995              if (!has_capability('moodle/user:update', $coursecontext)) {
4996                  // We can't edit the user so just show the user deleted message.
4997                  $usersetting->add(get_string('userdeleted'), null, self::TYPE_SETTING);
4998              } else {
4999                  // We can edit the user so show the user deleted message and link it to the profile.
5000                  if ($course->id == $SITE->id) {
5001                      $profileurl = new moodle_url('/user/profile.php', array('id'=>$user->id));
5002                  } else {
5003                      $profileurl = new moodle_url('/user/view.php', array('id'=>$user->id, 'course'=>$course->id));
5004                  }
5005                  $usersetting->add(get_string('userdeleted'), $profileurl, self::TYPE_SETTING);
5006              }
5007              return true;
5008          }
5009  
5010          $userauthplugin = false;
5011          if (!empty($user->auth)) {
5012              $userauthplugin = get_auth_plugin($user->auth);
5013          }
5014  
5015          $useraccount = $usersetting->add(get_string('useraccount'), null, self::TYPE_CONTAINER, null, 'useraccount');
5016  
5017          // Add the profile edit link.
5018          if (isloggedin() && !isguestuser($user) && !is_mnet_remote_user($user)) {
5019              if (($currentuser || is_siteadmin($USER) || !is_siteadmin($user)) &&
5020                      has_capability('moodle/user:update', $systemcontext)) {
5021                  $url = new moodle_url('/user/editadvanced.php', array('id'=>$user->id, 'course'=>$course->id));
5022                  $useraccount->add(get_string('editmyprofile'), $url, self::TYPE_SETTING, null, 'editprofile');
5023              } else if ((has_capability('moodle/user:editprofile', $usercontext) && !is_siteadmin($user)) ||
5024                      ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext))) {
5025                  if ($userauthplugin && $userauthplugin->can_edit_profile()) {
5026                      $url = $userauthplugin->edit_profile_url();
5027                      if (empty($url)) {
5028                          $url = new moodle_url('/user/edit.php', array('id'=>$user->id, 'course'=>$course->id));
5029                      }
5030                      $useraccount->add(get_string('editmyprofile'), $url, self::TYPE_SETTING, null, 'editprofile');
5031                  }
5032              }
5033          }
5034  
5035          // Change password link.
5036          if ($userauthplugin && $currentuser && !\core\session\manager::is_loggedinas() && !isguestuser() &&
5037                  has_capability('moodle/user:changeownpassword', $systemcontext) && $userauthplugin->can_change_password()) {
5038              $passwordchangeurl = $userauthplugin->change_password_url();
5039              if (empty($passwordchangeurl)) {
5040                  $passwordchangeurl = new moodle_url('/login/change_password.php', array('id'=>$course->id));
5041              }
5042              $useraccount->add(get_string("changepassword"), $passwordchangeurl, self::TYPE_SETTING, null, 'changepassword');
5043          }
5044  
5045          // Default homepage.
5046          $defaulthomepageuser = (!empty($CFG->defaulthomepage) && ($CFG->defaulthomepage == HOMEPAGE_USER));
5047          if (isloggedin() && !isguestuser($user) && $defaulthomepageuser) {
5048              if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5049                      has_capability('moodle/user:editprofile', $usercontext)) {
5050                  $url = new moodle_url('/user/defaulthomepage.php', ['id' => $user->id]);
5051                  $useraccount->add(get_string('defaulthomepageuser'), $url, self::TYPE_SETTING, null, 'defaulthomepageuser');
5052              }
5053          }
5054  
5055          if (isloggedin() && !isguestuser($user) && !is_mnet_remote_user($user)) {
5056              if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5057                      has_capability('moodle/user:editprofile', $usercontext)) {
5058                  $url = new moodle_url('/user/language.php', array('id' => $user->id, 'course' => $course->id));
5059                  $useraccount->add(get_string('preferredlanguage'), $url, self::TYPE_SETTING, null, 'preferredlanguage');
5060              }
5061          }
5062          $pluginmanager = core_plugin_manager::instance();
5063          $enabled = $pluginmanager->get_enabled_plugins('mod');
5064          if (isset($enabled['forum']) && isloggedin() && !isguestuser($user) && !is_mnet_remote_user($user)) {
5065              if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5066                      has_capability('moodle/user:editprofile', $usercontext)) {
5067                  $url = new moodle_url('/user/forum.php', array('id' => $user->id, 'course' => $course->id));
5068                  $useraccount->add(get_string('forumpreferences'), $url, self::TYPE_SETTING);
5069              }
5070          }
5071          $editors = editors_get_enabled();
5072          if (count($editors) > 1) {
5073              if (isloggedin() && !isguestuser($user) && !is_mnet_remote_user($user)) {
5074                  if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5075                          has_capability('moodle/user:editprofile', $usercontext)) {
5076                      $url = new moodle_url('/user/editor.php', array('id' => $user->id, 'course' => $course->id));
5077                      $useraccount->add(get_string('editorpreferences'), $url, self::TYPE_SETTING);
5078                  }
5079              }
5080          }
5081  
5082          // Add "Course preferences" link.
5083          if (isloggedin() && !isguestuser($user)) {
5084              if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5085                  has_capability('moodle/user:editprofile', $usercontext)) {
5086                  $url = new moodle_url('/user/course.php', array('id' => $user->id, 'course' => $course->id));
5087                  $useraccount->add(get_string('coursepreferences'), $url, self::TYPE_SETTING, null, 'coursepreferences');
5088              }
5089          }
5090  
5091          // Add "Calendar preferences" link.
5092          if (isloggedin() && !isguestuser($user)) {
5093              if ($currentuser && has_capability('moodle/user:editownprofile', $systemcontext) ||
5094                      has_capability('moodle/user:editprofile', $usercontext)) {
5095                  $url = new moodle_url('/user/calendar.php', array('id' => $user->id));
5096                  $useraccount->add(get_string('calendarpreferences', 'calendar'), $url, self::TYPE_SETTING, null, 'preferredcalendar');
5097              }
5098          }
5099  
5100          // View the roles settings.
5101          if (has_any_capability(array('moodle/role:assign', 'moodle/role:safeoverride', 'moodle/role:override',
5102                  'moodle/role:manage'), $usercontext)) {
5103              $roles = $usersetting->add(get_string('roles'), null, self::TYPE_SETTING);
5104  
5105              $url = new moodle_url('/admin/roles/usersroles.php', array('userid'=>$user->id, 'courseid'=>$course->id));
5106              $roles->add(get_string('thisusersroles', 'role'), $url, self::TYPE_SETTING);
5107  
5108              $assignableroles = get_assignable_roles($usercontext, ROLENAME_BOTH);
5109  
5110              if (!empty($assignableroles)) {
5111                  $url = new moodle_url('/admin/roles/assign.php',
5112                          array('contextid' => $usercontext->id, 'userid' => $user->id, 'courseid' => $course->id));
5113                  $roles->add(get_string('assignrolesrelativetothisuser', 'role'), $url, self::TYPE_SETTING);
5114              }
5115  
5116              if (has_capability('moodle/role:review', $usercontext) || count(get_overridable_roles($usercontext, ROLENAME_BOTH))>0) {
5117                  $url = new moodle_url('/admin/roles/permissions.php',
5118                          array('contextid' => $usercontext->id, 'userid' => $user->id, 'courseid' => $course->id));
5119                  $roles->add(get_string('permissions', 'role'), $url, self::TYPE_SETTING);
5120              }
5121  
5122              $url = new moodle_url('/admin/roles/check.php',
5123                      array('contextid' => $usercontext->id, 'userid' => $user->id, 'courseid' => $course->id));
5124              $roles->add(get_string('checkpermissions', 'role'), $url, self::TYPE_SETTING);
5125          }
5126  
5127          // Repositories.
5128          if (!$this->cache->cached('contexthasrepos'.$usercontext->id)) {
5129              require_once($CFG->dirroot . '/repository/lib.php');
5130              $editabletypes = repository::get_editable_types($usercontext);
5131              $haseditabletypes = !empty($editabletypes);
5132              unset($editabletypes);
5133              $this->cache->set('contexthasrepos'.$usercontext->id, $haseditabletypes);
5134          } else {
5135              $haseditabletypes = $this->cache->{'contexthasrepos'.$usercontext->id};
5136          }
5137          if ($haseditabletypes) {
5138              $repositories = $usersetting->add(get_string('repositories', 'repository'), null, self::TYPE_SETTING);
5139              $repositories->add(get_string('manageinstances', 'repository'), new moodle_url('/repository/manage_instances.php',
5140                  array('contextid' => $usercontext->id)));
5141          }
5142  
5143          // Portfolio.
5144          if ($currentuser && !empty($CFG->enableportfolios) && has_capability('moodle/portfolio:export', $systemcontext)) {
5145              require_once($CFG->libdir . '/portfoliolib.php');
5146              if (portfolio_has_visible_instances()) {
5147                  $portfolio = $usersetting->add(get_string('portfolios', 'portfolio'), null, self::TYPE_SETTING);
5148  
5149                  $url = new moodle_url('/user/portfolio.php', array('courseid'=>$course->id));
5150                  $portfolio->add(get_string('configure', 'portfolio'), $url, self::TYPE_SETTING);
5151  
5152                  $url = new moodle_url('/user/portfoliologs.php', array('courseid'=>$course->id));
5153                  $portfolio->add(get_string('logs', 'portfolio'), $url, self::TYPE_SETTING);
5154              }
5155          }
5156  
5157          $enablemanagetokens = false;
5158          if (!empty($CFG->enablerssfeeds)) {
5159              $enablemanagetokens = true;
5160          } else if (!is_siteadmin($USER->id)
5161               && !empty($CFG->enablewebservices)
5162               && has_capability('moodle/webservice:createtoken', context_system::instance()) ) {
5163              $enablemanagetokens = true;
5164          }
5165          // Security keys.
5166          if ($currentuser && $enablemanagetokens) {
5167              $url = new moodle_url('/user/managetoken.php', array('sesskey'=>sesskey()));
5168              $useraccount->add(get_string('securitykeys', 'webservice'), $url, self::TYPE_SETTING);
5169          }
5170  
5171          // Messaging.
5172          if (($currentuser && has_capability('moodle/user:editownmessageprofile', $systemcontext)) || (!isguestuser($user) &&
5173                  has_capability('moodle/user:editmessageprofile', $usercontext) && !is_primary_admin($user->id))) {
5174              $messagingurl = new moodle_url('/message/edit.php', array('id' => $user->id));
5175              $notificationsurl = new moodle_url('/message/notificationpreferences.php', array('userid' => $user->id));
5176              $useraccount->add(get_string('messagepreferences', 'message'), $messagingurl, self::TYPE_SETTING);
5177              $useraccount->add(get_string('notificationpreferences', 'message'), $notificationsurl, self::TYPE_SETTING);
5178          }
5179  
5180          // Blogs.
5181          if ($currentuser && !empty($CFG->enableblogs)) {
5182              $blog = $usersetting->add(get_string('blogs', 'blog'), null, navigation_node::TYPE_CONTAINER, null, 'blogs');
5183              if (has_capability('moodle/blog:view', $systemcontext)) {
5184                  $blog->add(get_string('preferences', 'blog'), new moodle_url('/blog/preferences.php'),
5185                          navigation_node::TYPE_SETTING);
5186              }
5187              if (!empty($CFG->useexternalblogs) && $CFG->maxexternalblogsperuser > 0 &&
5188                      has_capability('moodle/blog:manageexternal', $systemcontext)) {
5189                  $blog->add(get_string('externalblogs', 'blog'), new moodle_url('/blog/external_blogs.php'),
5190                          navigation_node::TYPE_SETTING);
5191                  $blog->add(get_string('addnewexternalblog', 'blog'), new moodle_url('/blog/external_blog_edit.php'),
5192                          navigation_node::TYPE_SETTING);
5193              }
5194              // Remove the blog node if empty.
5195              $blog->trim_if_empty();
5196          }
5197  
5198          // Badges.
5199          if ($currentuser && !empty($CFG->enablebadges)) {
5200              $badges = $usersetting->add(get_string('badges'), null, navigation_node::TYPE_CONTAINER, null, 'badges');
5201              if (has_capability('moodle/badges:manageownbadges', $usercontext)) {
5202                  $url = new moodle_url('/badges/mybadges.php');
5203                  $badges->add(get_string('managebadges', 'badges'), $url, self::TYPE_SETTING);
5204              }
5205              $badges->add(get_string('preferences', 'badges'), new moodle_url('/badges/preferences.php'),
5206                      navigation_node::TYPE_SETTING);
5207              if (!empty($CFG->badges_allowexternalbackpack)) {
5208                  $badges->add(get_string('backpackdetails', 'badges'), new moodle_url('/badges/mybackpack.php'),
5209                          navigation_node::TYPE_SETTING);
5210              }
5211          }
5212  
5213          // Let plugins hook into user settings navigation.
5214          $pluginsfunction = get_plugins_with_function('extend_navigation_user_settings', 'lib.php');
5215          foreach ($pluginsfunction as $plugintype => $plugins) {
5216              foreach ($plugins as $pluginfunction) {
5217                  $pluginfunction($usersetting, $user, $usercontext, $course, $coursecontext);
5218              }
5219          }
5220  
5221          return $usersetting;
5222      }
5223  
5224      /**
5225       * Loads block specific settings in the navigation
5226       *
5227       * @return navigation_node
5228       */
5229      protected function load_block_settings() {
5230          global $CFG;
5231  
5232          $blocknode = $this->add($this->context->get_context_name(), null, self::TYPE_SETTING, null, 'blocksettings');
5233          $blocknode->force_open();
5234  
5235          // Assign local roles
5236          if (get_assignable_roles($this->context, ROLENAME_ORIGINAL)) {
5237              $assignurl = new moodle_url('/'.$CFG->admin.'/roles/assign.php', array('contextid' => $this->context->id));
5238              $blocknode->add(get_string('assignroles', 'role'), $assignurl, self::TYPE_SETTING, null,
5239                  'roles', new pix_icon('i/assignroles', ''));
5240          }
5241  
5242          // Override roles
5243          if (has_capability('moodle/role:review', $this->context) or  count(get_overridable_roles($this->context))>0) {
5244              $url = new moodle_url('/'.$CFG->admin.'/roles/permissions.php', array('contextid'=>$this->context->id));
5245              $blocknode->add(get_string('permissions', 'role'), $url, self::TYPE_SETTING, null,
5246                  'permissions', new pix_icon('i/permissions', ''));
5247          }
5248          // Check role permissions
5249          if (has_any_capability(array('moodle/role:assign', 'moodle/role:safeoverride','moodle/role:override', 'moodle/role:assign'), $this->context)) {
5250              $url = new moodle_url('/'.$CFG->admin.'/roles/check.php', array('contextid'=>$this->context->id));
5251              $blocknode->add(get_string('checkpermissions', 'role'), $url, self::TYPE_SETTING, null,
5252                  'checkpermissions', new pix_icon('i/checkpermissions', ''));
5253          }
5254  
5255          // Add the context locking node.
5256          $this->add_context_locking_node($blocknode, $this->context);
5257  
5258          return $blocknode;
5259      }
5260  
5261      /**
5262       * Loads category specific settings in the navigation
5263       *
5264       * @return navigation_node
5265       */
5266      protected function load_category_settings() {
5267          global $CFG;
5268  
5269          // We can land here while being in the context of a block, in which case we
5270          // should get the parent context which should be the category one. See self::initialise().
5271          if ($this->context->contextlevel == CONTEXT_BLOCK) {
5272              $catcontext = $this->context->get_parent_context();
5273          } else {
5274              $catcontext = $this->context;
5275          }
5276  
5277          // Let's make sure that we always have the right context when getting here.
5278          if ($catcontext->contextlevel != CONTEXT_COURSECAT) {
5279              throw new coding_exception('Unexpected context while loading category settings.');
5280          }
5281  
5282          $categorynodetype = navigation_node::TYPE_CONTAINER;
5283          $categorynode = $this->add($catcontext->get_context_name(), null, $categorynodetype, null, 'categorysettings');
5284          $categorynode->nodetype = navigation_node::NODETYPE_BRANCH;
5285          $categorynode->force_open();
5286  
5287          if (can_edit_in_category($catcontext->instanceid)) {
5288              $url = new moodle_url('/course/management.php', array('categoryid' => $catcontext->instanceid));
5289              $editstring = get_string('managecategorythis');
5290              $categorynode->add($editstring, $url, self::TYPE_SETTING, null, null, new pix_icon('i/edit', ''));
5291          }
5292  
5293          if (has_capability('moodle/category:manage', $catcontext)) {
5294              $editurl = new moodle_url('/course/editcategory.php', array('id' => $catcontext->instanceid));
5295              $categorynode->add(get_string('editcategorythis'), $editurl, self::TYPE_SETTING, null, 'edit', new pix_icon('i/edit', ''));
5296  
5297              $addsubcaturl = new moodle_url('/course/editcategory.php', array('parent' => $catcontext->instanceid));
5298              $categorynode->add(get_string('addsubcategory'), $addsubcaturl, self::TYPE_SETTING, null, 'addsubcat', new pix_icon('i/withsubcat', ''));
5299          }
5300  
5301          // Assign local roles
5302          $assignableroles = get_assignable_roles($catcontext);
5303          if (!empty($assignableroles)) {
5304              $assignurl = new moodle_url('/'.$CFG->admin.'/roles/assign.php', array('contextid' => $catcontext->id));
5305              $categorynode->add(get_string('assignroles', 'role'), $assignurl, self::TYPE_SETTING, null, 'roles', new pix_icon('i/assignroles', ''));
5306          }
5307  
5308          // Override roles
5309          if (has_capability('moodle/role:review', $catcontext) or count(get_overridable_roles($catcontext)) > 0) {
5310              $url = new moodle_url('/'.$CFG->admin.'/roles/permissions.php', array('contextid' => $catcontext->id));
5311              $categorynode->add(get_string('permissions', 'role'), $url, self::TYPE_SETTING, null, 'permissions', new pix_icon('i/permissions', ''));
5312          }
5313          // Check role permissions
5314          if (has_any_capability(array('moodle/role:assign', 'moodle/role:safeoverride',
5315                  'moodle/role:override', 'moodle/role:assign'), $catcontext)) {
5316              $url = new moodle_url('/'.$CFG->admin.'/roles/check.php', array('contextid' => $catcontext->id));
5317              $categorynode->add(get_string('checkpermissions', 'role'), $url, self::TYPE_SETTING, null, 'checkpermissions', new pix_icon('i/checkpermissions', ''));
5318          }
5319  
5320          // Add the context locking node.
5321          $this->add_context_locking_node($categorynode, $catcontext);
5322  
5323          // Cohorts
5324          if (has_any_capability(array('moodle/cohort:view', 'moodle/cohort:manage'), $catcontext)) {
5325              $categorynode->add(get_string('cohorts', 'cohort'), new moodle_url('/cohort/index.php',
5326                  array('contextid' => $catcontext->id)), self::TYPE_SETTING, null, 'cohort', new pix_icon('i/cohort', ''));
5327          }
5328  
5329          // Manage filters
5330          if (has_capability('moodle/filter:manage', $catcontext) && count(filter_get_available_in_context($catcontext)) > 0) {
5331              $url = new moodle_url('/filter/manage.php', array('contextid' => $catcontext->id));
5332              $categorynode->add(get_string('filters', 'admin'), $url, self::TYPE_SETTING, null, 'filters', new pix_icon('i/filter', ''));
5333          }
5334  
5335          // Restore.
5336          if (has_capability('moodle/restore:restorecourse', $catcontext)) {
5337              $url = new moodle_url('/backup/restorefile.php', array('contextid' => $catcontext->id));
5338              $categorynode->add(get_string('restorecourse', 'admin'), $url, self::TYPE_SETTING, null, 'restorecourse', new pix_icon('i/restore', ''));
5339          }
5340  
5341          // Let plugins hook into category settings navigation.
5342          $pluginsfunction = get_plugins_with_function('extend_navigation_category_settings', 'lib.php');
5343          foreach ($pluginsfunction as $plugintype => $plugins) {
5344              foreach ($plugins as $pluginfunction) {
5345                  $pluginfunction($categorynode, $catcontext);
5346              }
5347          }
5348  
5349          return $categorynode;
5350      }
5351  
5352      /**
5353       * Determine whether the user is assuming another role
5354       *
5355       * This function checks to see if the user is assuming another role by means of
5356       * role switching. In doing this we compare each RSW key (context path) against
5357       * the current context path. This ensures that we can provide the switching
5358       * options against both the course and any page shown under the course.
5359       *
5360       * @return bool|int The role(int) if the user is in another role, false otherwise
5361       */
5362      protected function in_alternative_role() {
5363          global $USER;
5364          if (!empty($USER->access['rsw']) && is_array($USER->access['rsw'])) {
5365              if (!empty($this->page->context) && !empty($USER->access['rsw'][$this->page->context->path])) {
5366                  return $USER->access['rsw'][$this->page->context->path];
5367              }
5368              foreach ($USER->access['rsw'] as $key=>$role) {
5369                  if (strpos($this->context->path,$key)===0) {
5370                      return $role;
5371                  }
5372              }
5373          }
5374          return false;
5375      }
5376  
5377      /**
5378       * This function loads all of the front page settings into the settings navigation.
5379       * This function is called when the user is on the front page, or $COURSE==$SITE
5380       * @param bool $forceopen (optional)
5381       * @return navigation_node
5382       */
5383      protected function load_front_page_settings($forceopen = false) {
5384          global $SITE, $CFG;
5385          require_once($CFG->dirroot . '/course/lib.php');
5386  
5387          $course = clone($SITE);
5388          $coursecontext = context_course::instance($course->id);   // Course context
5389          $adminoptions = course_get_user_administration_options($course, $coursecontext);
5390  
5391          $frontpage = $this->add(get_string('frontpagesettings'), null, self::TYPE_SETTING, null, 'frontpage');
5392          if ($forceopen) {
5393              $frontpage->force_open();
5394          }
5395          $frontpage->id = 'frontpagesettings';
5396  
5397          if ($this->page->user_allowed_editing()) {
5398  
5399              // Add the turn on/off settings
5400              $url = new moodle_url('/course/view.php', array('id'=>$course->id, 'sesskey'=>sesskey()));
5401              if ($this->page->user_is_editing()) {
5402                  $url->param('edit', 'off');
5403                  $editstring = get_string('turneditingoff');
5404              } else {
5405                  $url->param('edit', 'on');
5406                  $editstring = get_string('turneditingon');
5407              }
5408              $frontpage->add($editstring, $url, self::TYPE_SETTING, null, null, new pix_icon('i/edit', ''));
5409          }
5410  
5411          if ($adminoptions->update) {
5412              // Add the course settings link
5413              $url = new moodle_url('/admin/settings.php', array('section'=>'frontpagesettings'));
5414              $frontpage->add(get_string('editsettings'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/settings', ''));
5415          }
5416  
5417          // add enrol nodes
5418          enrol_add_course_navigation($frontpage, $course);
5419  
5420          // Manage filters
5421          if ($adminoptions->filters) {
5422              $url = new moodle_url('/filter/manage.php', array('contextid'=>$coursecontext->id));
5423              $frontpage->add(get_string('filters', 'admin'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/filter', ''));
5424          }
5425  
5426          // View course reports.
5427          if ($adminoptions->reports) {
5428              $frontpagenav = $frontpage->add(get_string('reports'), null, self::TYPE_CONTAINER, null, 'frontpagereports',
5429                      new pix_icon('i/stats', ''));
5430              $coursereports = core_component::get_plugin_list('coursereport');
5431              foreach ($coursereports as $report=>$dir) {
5432                  $libfile = $CFG->dirroot.'/course/report/'.$report.'/lib.php';
5433                  if (file_exists($libfile)) {
5434                      require_once($libfile);
5435                      $reportfunction = $report.'_report_extend_navigation';
5436                      if (function_exists($report.'_report_extend_navigation')) {
5437                          $reportfunction($frontpagenav, $course, $coursecontext);
5438                      }
5439                  }
5440              }
5441  
5442              $reports = get_plugin_list_with_function('report', 'extend_navigation_course', 'lib.php');
5443              foreach ($reports as $reportfunction) {
5444                  $reportfunction($frontpagenav, $course, $coursecontext);
5445              }
5446          }
5447  
5448          // Backup this course
5449          if ($adminoptions->backup) {
5450              $url = new moodle_url('/backup/backup.php', array('id'=>$course->id));
5451              $frontpage->add(get_string('backup'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/backup', ''));
5452          }
5453  
5454          // Restore to this course
5455          if ($adminoptions->restore) {
5456              $url = new moodle_url('/backup/restorefile.php', array('contextid'=>$coursecontext->id));
5457              $frontpage->add(get_string('restore'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/restore', ''));
5458          }
5459  
5460          // Questions
5461          require_once($CFG->libdir . '/questionlib.php');
5462          question_extend_settings_navigation($frontpage, $coursecontext)->trim_if_empty();
5463  
5464          // Manage files
5465          if ($adminoptions->files) {
5466              //hiden in new installs
5467              $url = new moodle_url('/files/index.php', array('contextid'=>$coursecontext->id));
5468              $frontpage->add(get_string('sitelegacyfiles'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/folder', ''));
5469          }
5470  
5471          // Let plugins hook into frontpage navigation.
5472          $pluginsfunction = get_plugins_with_function('extend_navigation_frontpage', 'lib.php');
5473          foreach ($pluginsfunction as $plugintype => $plugins) {
5474              foreach ($plugins as $pluginfunction) {
5475                  $pluginfunction($frontpage, $course, $coursecontext);
5476              }
5477          }
5478  
5479          return $frontpage;
5480      }
5481  
5482      /**
5483       * This function gives local plugins an opportunity to modify the settings navigation.
5484       */
5485      protected function load_local_plugin_settings() {
5486  
5487          foreach (get_plugin_list_with_function('local', 'extend_settings_navigation') as $function) {
5488              $function($this, $this->context);
5489          }
5490      }
5491  
5492      /**
5493       * This function marks the cache as volatile so it is cleared during shutdown
5494       */
5495      public function clear_cache() {
5496          $this->cache->volatile();
5497      }
5498  
5499      /**
5500       * Checks to see if there are child nodes available in the specific user's preference node.
5501       * If so, then they have the appropriate permissions view this user's preferences.
5502       *
5503       * @since Moodle 2.9.3
5504       * @param int $userid The user's ID.
5505       * @return bool True if child nodes exist to view, otherwise false.
5506       */
5507      public function can_view_user_preferences($userid) {
5508          if (is_siteadmin()) {
5509              return true;
5510          }
5511          // See if any nodes are present in the preferences section for this user.
5512          $preferencenode = $this->find('userviewingsettings' . $userid, null);
5513          if ($preferencenode && $preferencenode->has_children()) {
5514              // Run through each child node.
5515              foreach ($preferencenode->children as $childnode) {
5516                  // If the child node has children then this user has access to a link in the preferences page.
5517                  if ($childnode->has_children()) {
5518                      return true;
5519                  }
5520              }
5521          }
5522          // No links found for the user to access on the preferences page.
5523          return false;
5524      }
5525  }
5526  
5527  /**
5528   * Class used to populate site admin navigation for ajax.
5529   *
5530   * @package   core
5531   * @category  navigation
5532   * @copyright 2013 Rajesh Taneja <rajesh@moodle.com>
5533   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
5534   */
5535  class settings_navigation_ajax extends settings_navigation {
5536      /**
5537       * Constructs the navigation for use in an AJAX request
5538       *
5539       * @param moodle_page $page
5540       */
5541      public function __construct(moodle_page &$page) {
5542          $this->page = $page;
5543          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
5544          $this->children = new navigation_node_collection();
5545          $this->initialise();
5546      }
5547  
5548      /**
5549       * Initialise the site admin navigation.
5550       *
5551       * @return array An array of the expandable nodes
5552       */
5553      public function initialise() {
5554          if ($this->initialised || during_initial_install()) {
5555              return false;
5556          }
5557          $this->context = $this->page->context;
5558          $this->load_administration_settings();
5559  
5560          // Check if local plugins is adding node to site admin.
5561          $this->load_local_plugin_settings();
5562  
5563          $this->initialised = true;
5564      }
5565  }
5566  
5567  /**
5568   * Simple class used to output a navigation branch in XML
5569   *
5570   * @package   core
5571   * @category  navigation
5572   * @copyright 2009 Sam Hemelryk
5573   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
5574   */
5575  class navigation_json {
5576      /** @var array An array of different node types */
5577      protected $nodetype = array('node','branch');
5578      /** @var array An array of node keys and types */
5579      protected $expandable = array();
5580      /**
5581       * Turns a branch and all of its children into XML
5582       *
5583       * @param navigation_node $branch
5584       * @return string XML string
5585       */
5586      public function convert($branch) {
5587          $xml = $this->convert_child($branch);
5588          return $xml;
5589      }
5590      /**
5591       * Set the expandable items in the array so that we have enough information
5592       * to attach AJAX events
5593       * @param array $expandable
5594       */
5595      public function set_expandable($expandable) {
5596          foreach ($expandable as $node) {
5597              $this->expandable[$node['key'].':'.$node['type']] = $node;
5598          }
5599      }
5600      /**
5601       * Recusively converts a child node and its children to XML for output
5602       *
5603       * @param navigation_node $child The child to convert
5604       * @param int $depth Pointlessly used to track the depth of the XML structure
5605       * @return string JSON
5606       */
5607      protected function convert_child($child, $depth=1) {
5608          if (!$child->display) {
5609              return '';
5610          }
5611          $attributes = array();
5612          $attributes['id'] = $child->id;
5613          $attributes['name'] = (string)$child->text; // This can be lang_string object so typecast it.
5614          $attributes['type'] = $child->type;
5615          $attributes['key'] = $child->key;
5616          $attributes['class'] = $child->get_css_type();
5617          $attributes['requiresajaxloading'] = $child->requiresajaxloading;
5618  
5619          if ($child->icon instanceof pix_icon) {
5620              $attributes['icon'] = array(
5621                  'component' => $child->icon->component,
5622                  'pix' => $child->icon->pix,
5623              );
5624              foreach ($child->icon->attributes as $key=>$value) {
5625                  if ($key == 'class') {
5626                      $attributes['icon']['classes'] = explode(' ', $value);
5627                  } else if (!array_key_exists($key, $attributes['icon'])) {
5628                      $attributes['icon'][$key] = $value;
5629                  }
5630  
5631              }
5632          } else if (!empty($child->icon)) {
5633              $attributes['icon'] = (string)$child->icon;
5634          }
5635  
5636          if ($child->forcetitle || $child->title !== $child->text) {
5637              $attributes['title'] = htmlentities($child->title, ENT_QUOTES, 'UTF-8');
5638          }
5639          if (array_key_exists($child->key.':'.$child->type, $this->expandable)) {
5640              $attributes['expandable'] = $child->key;
5641              $child->add_class($this->expandable[$child->key.':'.$child->type]['id']);
5642          }
5643  
5644          if (count($child->classes)>0) {
5645              $attributes['class'] .= ' '.join(' ',$child->classes);
5646          }
5647          if (is_string($child->action)) {
5648              $attributes['link'] = $child->action;
5649          } else if ($child->action instanceof moodle_url) {
5650              $attributes['link'] = $child->action->out();
5651          } else if ($child->action instanceof action_link) {
5652              $attributes['link'] = $child->action->url->out();
5653          }
5654          $attributes['hidden'] = ($child->hidden);
5655          $attributes['haschildren'] = ($child->children->count()>0 || $child->type == navigation_node::TYPE_CATEGORY);
5656          $attributes['haschildren'] = $attributes['haschildren'] || $child->type == navigation_node::TYPE_MY_CATEGORY;
5657  
5658          if ($child->children->count() > 0) {
5659              $attributes['children'] = array();
5660              foreach ($child->children as $subchild) {
5661                  $attributes['children'][] = $this->convert_child($subchild, $depth+1);
5662              }
5663          }
5664  
5665          if ($depth > 1) {
5666              return $attributes;
5667          } else {
5668              return json_encode($attributes);
5669          }
5670      }
5671  }
5672  
5673  /**
5674   * The cache class used by global navigation and settings navigation.
5675   *
5676   * It is basically an easy access point to session with a bit of smarts to make
5677   * sure that the information that is cached is valid still.
5678   *
5679   * Example use:
5680   * <code php>
5681   * if (!$cache->viewdiscussion()) {
5682   *     // Code to do stuff and produce cachable content
5683   *     $cache->viewdiscussion = has_capability('mod/forum:viewdiscussion', $coursecontext);
5684   * }
5685   * $content = $cache->viewdiscussion;
5686   * </code>
5687   *
5688   * @package   core
5689   * @category  navigation
5690   * @copyright 2009 Sam Hemelryk
5691   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
5692   */
5693  class navigation_cache {
5694      /** @var int represents the time created */
5695      protected $creation;
5696      /** @var array An array of session keys */
5697      protected $session;
5698      /**
5699       * The string to use to segregate this particular cache. It can either be
5700       * unique to start a fresh cache or if you want to share a cache then make
5701       * it the string used in the original cache.
5702       * @var string
5703       */
5704      protected $area;
5705      /** @var int a time that the information will time out */
5706      protected $timeout;
5707      /** @var stdClass The current context */
5708      protected $currentcontext;
5709      /** @var int cache time information */
5710      const CACHETIME = 0;
5711      /** @var int cache user id */
5712      const CACHEUSERID = 1;
5713      /** @var int cache value */
5714      const CACHEVALUE = 2;
5715      /** @var null|array An array of navigation cache areas to expire on shutdown */
5716      public static $volatilecaches;
5717  
5718      /**
5719       * Contructor for the cache. Requires two arguments
5720       *
5721       * @param string $area The string to use to segregate this particular cache
5722       *                it can either be unique to start a fresh cache or if you want
5723       *                to share a cache then make it the string used in the original
5724       *                cache
5725       * @param int $timeout The number of seconds to time the information out after
5726       */
5727      public function __construct($area, $timeout=1800) {
5728          $this->creation = time();
5729          $this->area = $area;
5730          $this->timeout = time() - $timeout;
5731          if (rand(0,100) === 0) {
5732              $this->garbage_collection();
5733          }
5734      }
5735  
5736      /**
5737       * Used to set up the cache within the SESSION.
5738       *
5739       * This is called for each access and ensure that we don't put anything into the session before
5740       * it is required.
5741       */
5742      protected function ensure_session_cache_initialised() {
5743          global $SESSION;
5744          if (empty($this->session)) {
5745              if (!isset($SESSION->navcache)) {
5746                  $SESSION->navcache = new stdClass;
5747              }
5748              if (!isset($SESSION->navcache->{$this->area})) {
5749                  $SESSION->navcache->{$this->area} = array();
5750              }
5751              $this->session = &$SESSION->navcache->{$this->area}; // pointer to array, =& is correct here
5752          }
5753      }
5754  
5755      /**
5756       * Magic Method to retrieve something by simply calling using = cache->key
5757       *
5758       * @param mixed $key The identifier for the information you want out again
5759       * @return void|mixed Either void or what ever was put in
5760       */
5761      public function __get($key) {
5762          if (!$this->cached($key)) {
5763              return;
5764          }
5765          $information = $this->session[$key][self::CACHEVALUE];
5766          return unserialize($information);
5767      }
5768  
5769      /**
5770       * Magic method that simply uses {@link set();} to store something in the cache
5771       *
5772       * @param string|int $key
5773       * @param mixed $information
5774       */
5775      public function __set($key, $information) {
5776          $this->set($key, $information);
5777      }
5778  
5779      /**
5780       * Sets some information against the cache (session) for later retrieval
5781       *
5782       * @param string|int $key
5783       * @param mixed $information
5784       */
5785      public function set($key, $information) {
5786          global $USER;
5787          $this->ensure_session_cache_initialised();
5788          $information = serialize($information);
5789          $this->session[$key]= array(self::CACHETIME=>time(), self::CACHEUSERID=>$USER->id, self::CACHEVALUE=>$information);
5790      }
5791      /**
5792       * Check the existence of the identifier in the cache
5793       *
5794       * @param string|int $key
5795       * @return bool
5796       */
5797      public function cached($key) {
5798          global $USER;
5799          $this->ensure_session_cache_initialised();
5800          if (!array_key_exists($key, $this->session) || !is_array($this->session[$key]) || $this->session[$key][self::CACHEUSERID]!=$USER->id || $this->session[$key][self::CACHETIME] < $this->timeout) {
5801              return false;
5802          }
5803          return true;
5804      }
5805      /**
5806       * Compare something to it's equivilant in the cache
5807       *
5808       * @param string $key
5809       * @param mixed $value
5810       * @param bool $serialise Whether to serialise the value before comparison
5811       *              this should only be set to false if the value is already
5812       *              serialised
5813       * @return bool If the value is the same false if it is not set or doesn't match
5814       */
5815      public function compare($key, $value, $serialise = true) {
5816          if ($this->cached($key)) {
5817              if ($serialise) {
5818                  $value = serialize($value);
5819              }
5820              if ($this->session[$key][self::CACHEVALUE] === $value) {
5821                  return true;
5822              }
5823          }
5824          return false;
5825      }
5826      /**
5827       * Wipes the entire cache, good to force regeneration
5828       */
5829      public function clear() {
5830          global $SESSION;
5831          unset($SESSION->navcache);
5832          $this->session = null;
5833      }
5834      /**
5835       * Checks all cache entries and removes any that have expired, good ole cleanup
5836       */
5837      protected function garbage_collection() {
5838          if (empty($this->session)) {
5839              return true;
5840          }
5841          foreach ($this->session as $key=>$cachedinfo) {
5842              if (is_array($cachedinfo) && $cachedinfo[self::CACHETIME]<$this->timeout) {
5843                  unset($this->session[$key]);
5844              }
5845          }
5846      }
5847  
5848      /**
5849       * Marks the cache as being volatile (likely to change)
5850       *
5851       * Any caches marked as volatile will be destroyed at the on shutdown by
5852       * {@link navigation_node::destroy_volatile_caches()} which is registered
5853       * as a shutdown function if any caches are marked as volatile.
5854       *
5855       * @param bool $setting True to destroy the cache false not too
5856       */
5857      public function volatile($setting = true) {
5858          if (self::$volatilecaches===null) {
5859              self::$volatilecaches = array();
5860              core_shutdown_manager::register_function(array('navigation_cache','destroy_volatile_caches'));
5861          }
5862  
5863          if ($setting) {
5864              self::$volatilecaches[$this->area] = $this->area;
5865          } else if (array_key_exists($this->area, self::$volatilecaches)) {
5866              unset(self::$volatilecaches[$this->area]);
5867          }
5868      }
5869  
5870      /**
5871       * Destroys all caches marked as volatile
5872       *
5873       * This function is static and works in conjunction with the static volatilecaches
5874       * property of navigation cache.
5875       * Because this function is static it manually resets the cached areas back to an
5876       * empty array.
5877       */
5878      public static function destroy_volatile_caches() {
5879          global $SESSION;
5880          if (is_array(self::$volatilecaches) && count(self::$volatilecaches)>0) {
5881              foreach (self::$volatilecaches as $area) {
5882                  $SESSION->navcache->{$area} = array();
5883              }
5884          } else {
5885              $SESSION->navcache = new stdClass;
5886          }
5887      }
5888  }