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   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  
  88      /** @var int Parameter to aid the coder in tracking [optional] */
  89      public $id = null;
  90      /** @var string|int The identifier for the node, used to retrieve the node */
  91      public $key = null;
  92      /** @var string The text to use for the node */
  93      public $text = null;
  94      /** @var string Short text to use if requested [optional] */
  95      public $shorttext = null;
  96      /** @var string The title attribute for an action if one is defined */
  97      public $title = null;
  98      /** @var string A string that can be used to build a help button */
  99      public $helpbutton = null;
 100      /** @var moodle_url|action_link|null An action for the node (link) */
 101      public $action = null;
 102      /** @var pix_icon The path to an icon to use for this node */
 103      public $icon = null;
 104      /** @var int See TYPE_* constants defined for this class */
 105      public $type = self::TYPE_UNKNOWN;
 106      /** @var int See NODETYPE_* constants defined for this class */
 107      public $nodetype = self::NODETYPE_LEAF;
 108      /** @var bool If set to true the node will be collapsed by default */
 109      public $collapse = false;
 110      /** @var bool If set to true the node will be expanded by default */
 111      public $forceopen = false;
 112      /** @var array An array of CSS classes for the node */
 113      public $classes = array();
 114      /** @var navigation_node_collection An array of child nodes */
 115      public $children = array();
 116      /** @var bool If set to true the node will be recognised as active */
 117      public $isactive = false;
 118      /** @var bool If set to true the node will be dimmed */
 119      public $hidden = false;
 120      /** @var bool If set to false the node will not be displayed */
 121      public $display = true;
 122      /** @var bool If set to true then an HR will be printed before the node */
 123      public $preceedwithhr = false;
 124      /** @var bool If set to true the the navigation bar should ignore this node */
 125      public $mainnavonly = false;
 126      /** @var bool If set to true a title will be added to the action no matter what */
 127      public $forcetitle = false;
 128      /** @var navigation_node A reference to the node parent, you should never set this directly you should always call set_parent */
 129      public $parent = null;
 130      /** @var bool Override to not display the icon even if one is provided **/
 131      public $hideicon = false;
 132      /** @var bool Set to true if we KNOW that this node can be expanded.  */
 133      public $isexpandable = false;
 134      /** @var array */
 135      protected $namedtypes = array(0=>'system',10=>'category',20=>'course',30=>'structure',40=>'activity',50=>'resource',60=>'custom',70=>'setting',71=>'siteadmin', 80=>'user');
 136      /** @var moodle_url */
 137      protected static $fullmeurl = null;
 138      /** @var bool toogles auto matching of active node */
 139      public static $autofindactive = true;
 140      /** @var bool should we load full admin tree or rely on AJAX for performance reasons */
 141      protected static $loadadmintree = false;
 142      /** @var mixed If set to an int, that section will be included even if it has no activities */
 143      public $includesectionnum = false;
 144  
 145      /**
 146       * Constructs a new navigation_node
 147       *
 148       * @param array|string $properties Either an array of properties or a string to use
 149       *                     as the text for the node
 150       */
 151      public function __construct($properties) {
 152          if (is_array($properties)) {
 153              // Check the array for each property that we allow to set at construction.
 154              // text         - The main content for the node
 155              // shorttext    - A short text if required for the node
 156              // icon         - The icon to display for the node
 157              // type         - The type of the node
 158              // key          - The key to use to identify the node
 159              // parent       - A reference to the nodes parent
 160              // action       - The action to attribute to this node, usually a URL to link to
 161              if (array_key_exists('text', $properties)) {
 162                  $this->text = $properties['text'];
 163              }
 164              if (array_key_exists('shorttext', $properties)) {
 165                  $this->shorttext = $properties['shorttext'];
 166              }
 167              if (!array_key_exists('icon', $properties)) {
 168                  $properties['icon'] = new pix_icon('i/navigationitem', '');
 169              }
 170              $this->icon = $properties['icon'];
 171              if ($this->icon instanceof pix_icon) {
 172                  if (empty($this->icon->attributes['class'])) {
 173                      $this->icon->attributes['class'] = 'navicon';
 174                  } else {
 175                      $this->icon->attributes['class'] .= ' navicon';
 176                  }
 177              }
 178              if (array_key_exists('type', $properties)) {
 179                  $this->type = $properties['type'];
 180              } else {
 181                  $this->type = self::TYPE_CUSTOM;
 182              }
 183              if (array_key_exists('key', $properties)) {
 184                  $this->key = $properties['key'];
 185              }
 186              // This needs to happen last because of the check_if_active call that occurs
 187              if (array_key_exists('action', $properties)) {
 188                  $this->action = $properties['action'];
 189                  if (is_string($this->action)) {
 190                      $this->action = new moodle_url($this->action);
 191                  }
 192                  if (self::$autofindactive) {
 193                      $this->check_if_active();
 194                  }
 195              }
 196              if (array_key_exists('parent', $properties)) {
 197                  $this->set_parent($properties['parent']);
 198              }
 199          } else if (is_string($properties)) {
 200              $this->text = $properties;
 201          }
 202          if ($this->text === null) {
 203              throw new coding_exception('You must set the text for the node when you create it.');
 204          }
 205          // Instantiate a new navigation node collection for this nodes children
 206          $this->children = new navigation_node_collection();
 207      }
 208  
 209      /**
 210       * Checks if this node is the active node.
 211       *
 212       * This is determined by comparing the action for the node against the
 213       * defined URL for the page. A match will see this node marked as active.
 214       *
 215       * @param int $strength One of URL_MATCH_EXACT, URL_MATCH_PARAMS, or URL_MATCH_BASE
 216       * @return bool
 217       */
 218      public function check_if_active($strength=URL_MATCH_EXACT) {
 219          global $FULLME, $PAGE;
 220          // Set fullmeurl if it hasn't already been set
 221          if (self::$fullmeurl == null) {
 222              if ($PAGE->has_set_url()) {
 223                  self::override_active_url(new moodle_url($PAGE->url));
 224              } else {
 225                  self::override_active_url(new moodle_url($FULLME));
 226              }
 227          }
 228  
 229          // Compare the action of this node against the fullmeurl
 230          if ($this->action instanceof moodle_url && $this->action->compare(self::$fullmeurl, $strength)) {
 231              $this->make_active();
 232              return true;
 233          }
 234          return false;
 235      }
 236  
 237      /**
 238       * This sets the URL that the URL of new nodes get compared to when locating
 239       * the active node.
 240       *
 241       * The active node is the node that matches the URL set here. By default this
 242       * is either $PAGE->url or if that hasn't been set $FULLME.
 243       *
 244       * @param moodle_url $url The url to use for the fullmeurl.
 245       * @param bool $loadadmintree use true if the URL point to administration tree
 246       */
 247      public static function override_active_url(moodle_url $url, $loadadmintree = false) {
 248          // Clone the URL, in case the calling script changes their URL later.
 249          self::$fullmeurl = new moodle_url($url);
 250          // True means we do not want AJAX loaded admin tree, required for all admin pages.
 251          if ($loadadmintree) {
 252              // Do not change back to false if already set.
 253              self::$loadadmintree = true;
 254          }
 255      }
 256  
 257      /**
 258       * Use when page is linked from the admin tree,
 259       * if not used navigation could not find the page using current URL
 260       * because the tree is not fully loaded.
 261       */
 262      public static function require_admin_tree() {
 263          self::$loadadmintree = true;
 264      }
 265  
 266      /**
 267       * Creates a navigation node, ready to add it as a child using add_node
 268       * function. (The created node needs to be added before you can use it.)
 269       * @param string $text
 270       * @param moodle_url|action_link $action
 271       * @param int $type
 272       * @param string $shorttext
 273       * @param string|int $key
 274       * @param pix_icon $icon
 275       * @return navigation_node
 276       */
 277      public static function create($text, $action=null, $type=self::TYPE_CUSTOM,
 278              $shorttext=null, $key=null, pix_icon $icon=null) {
 279          // Properties array used when creating the new navigation node
 280          $itemarray = array(
 281              'text' => $text,
 282              'type' => $type
 283          );
 284          // Set the action if one was provided
 285          if ($action!==null) {
 286              $itemarray['action'] = $action;
 287          }
 288          // Set the shorttext if one was provided
 289          if ($shorttext!==null) {
 290              $itemarray['shorttext'] = $shorttext;
 291          }
 292          // Set the icon if one was provided
 293          if ($icon!==null) {
 294              $itemarray['icon'] = $icon;
 295          }
 296          // Set the key
 297          $itemarray['key'] = $key;
 298          // Construct and return
 299          return new navigation_node($itemarray);
 300      }
 301  
 302      /**
 303       * Adds a navigation node as a child of this node.
 304       *
 305       * @param string $text
 306       * @param moodle_url|action_link $action
 307       * @param int $type
 308       * @param string $shorttext
 309       * @param string|int $key
 310       * @param pix_icon $icon
 311       * @return navigation_node
 312       */
 313      public function add($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
 314          // Create child node
 315          $childnode = self::create($text, $action, $type, $shorttext, $key, $icon);
 316  
 317          // Add the child to end and return
 318          return $this->add_node($childnode);
 319      }
 320  
 321      /**
 322       * Adds a navigation node as a child of this one, given a $node object
 323       * created using the create function.
 324       * @param navigation_node $childnode Node to add
 325       * @param string $beforekey
 326       * @return navigation_node The added node
 327       */
 328      public function add_node(navigation_node $childnode, $beforekey=null) {
 329          // First convert the nodetype for this node to a branch as it will now have children
 330          if ($this->nodetype !== self::NODETYPE_BRANCH) {
 331              $this->nodetype = self::NODETYPE_BRANCH;
 332          }
 333          // Set the parent to this node
 334          $childnode->set_parent($this);
 335  
 336          // Default the key to the number of children if not provided
 337          if ($childnode->key === null) {
 338              $childnode->key = $this->children->count();
 339          }
 340  
 341          // Add the child using the navigation_node_collections add method
 342          $node = $this->children->add($childnode, $beforekey);
 343  
 344          // If added node is a category node or the user is logged in and it's a course
 345          // then mark added node as a branch (makes it expandable by AJAX)
 346          $type = $childnode->type;
 347          if (($type == self::TYPE_CATEGORY) || (isloggedin() && ($type == self::TYPE_COURSE)) || ($type == self::TYPE_MY_CATEGORY) ||
 348                  ($type === self::TYPE_SITE_ADMIN)) {
 349              $node->nodetype = self::NODETYPE_BRANCH;
 350          }
 351          // If this node is hidden mark it's children as hidden also
 352          if ($this->hidden) {
 353              $node->hidden = true;
 354          }
 355          // Return added node (reference returned by $this->children->add()
 356          return $node;
 357      }
 358  
 359      /**
 360       * Return a list of all the keys of all the child nodes.
 361       * @return array the keys.
 362       */
 363      public function get_children_key_list() {
 364          return $this->children->get_key_list();
 365      }
 366  
 367      /**
 368       * Searches for a node of the given type with the given key.
 369       *
 370       * This searches this node plus all of its children, and their children....
 371       * If you know the node you are looking for is a child of this node then please
 372       * use the get method instead.
 373       *
 374       * @param int|string $key The key of the node we are looking for
 375       * @param int $type One of navigation_node::TYPE_*
 376       * @return navigation_node|false
 377       */
 378      public function find($key, $type) {
 379          return $this->children->find($key, $type);
 380      }
 381  
 382      /**
 383       * Get the child of this node that has the given key + (optional) type.
 384       *
 385       * If you are looking for a node and want to search all children + thier children
 386       * then please use the find method instead.
 387       *
 388       * @param int|string $key The key of the node we are looking for
 389       * @param int $type One of navigation_node::TYPE_*
 390       * @return navigation_node|false
 391       */
 392      public function get($key, $type=null) {
 393          return $this->children->get($key, $type);
 394      }
 395  
 396      /**
 397       * Removes this node.
 398       *
 399       * @return bool
 400       */
 401      public function remove() {
 402          return $this->parent->children->remove($this->key, $this->type);
 403      }
 404  
 405      /**
 406       * Checks if this node has or could have any children
 407       *
 408       * @return bool Returns true if it has children or could have (by AJAX expansion)
 409       */
 410      public function has_children() {
 411          return ($this->nodetype === navigation_node::NODETYPE_BRANCH || $this->children->count()>0 || $this->isexpandable);
 412      }
 413  
 414      /**
 415       * Marks this node as active and forces it open.
 416       *
 417       * Important: If you are here because you need to mark a node active to get
 418       * the navigation to do what you want have you looked at {@link navigation_node::override_active_url()}?
 419       * You can use it to specify a different URL to match the active navigation node on
 420       * rather than having to locate and manually mark a node active.
 421       */
 422      public function make_active() {
 423          $this->isactive = true;
 424          $this->add_class('active_tree_node');
 425          $this->force_open();
 426          if ($this->parent !== null) {
 427              $this->parent->make_inactive();
 428          }
 429      }
 430  
 431      /**
 432       * Marks a node as inactive and recusised back to the base of the tree
 433       * doing the same to all parents.
 434       */
 435      public function make_inactive() {
 436          $this->isactive = false;
 437          $this->remove_class('active_tree_node');
 438          if ($this->parent !== null) {
 439              $this->parent->make_inactive();
 440          }
 441      }
 442  
 443      /**
 444       * Forces this node to be open and at the same time forces open all
 445       * parents until the root node.
 446       *
 447       * Recursive.
 448       */
 449      public function force_open() {
 450          $this->forceopen = true;
 451          if ($this->parent !== null) {
 452              $this->parent->force_open();
 453          }
 454      }
 455  
 456      /**
 457       * Adds a CSS class to this node.
 458       *
 459       * @param string $class
 460       * @return bool
 461       */
 462      public function add_class($class) {
 463          if (!in_array($class, $this->classes)) {
 464              $this->classes[] = $class;
 465          }
 466          return true;
 467      }
 468  
 469      /**
 470       * Removes a CSS class from this node.
 471       *
 472       * @param string $class
 473       * @return bool True if the class was successfully removed.
 474       */
 475      public function remove_class($class) {
 476          if (in_array($class, $this->classes)) {
 477              $key = array_search($class,$this->classes);
 478              if ($key!==false) {
 479                  unset($this->classes[$key]);
 480                  return true;
 481              }
 482          }
 483          return false;
 484      }
 485  
 486      /**
 487       * Sets the title for this node and forces Moodle to utilise it.
 488       * @param string $title
 489       */
 490      public function title($title) {
 491          $this->title = $title;
 492          $this->forcetitle = true;
 493      }
 494  
 495      /**
 496       * Resets the page specific information on this node if it is being unserialised.
 497       */
 498      public function __wakeup(){
 499          $this->forceopen = false;
 500          $this->isactive = false;
 501          $this->remove_class('active_tree_node');
 502      }
 503  
 504      /**
 505       * Checks if this node or any of its children contain the active node.
 506       *
 507       * Recursive.
 508       *
 509       * @return bool
 510       */
 511      public function contains_active_node() {
 512          if ($this->isactive) {
 513              return true;
 514          } else {
 515              foreach ($this->children as $child) {
 516                  if ($child->isactive || $child->contains_active_node()) {
 517                      return true;
 518                  }
 519              }
 520          }
 521          return false;
 522      }
 523  
 524      /**
 525       * Finds the active node.
 526       *
 527       * Searches this nodes children plus all of the children for the active node
 528       * and returns it if found.
 529       *
 530       * Recursive.
 531       *
 532       * @return navigation_node|false
 533       */
 534      public function find_active_node() {
 535          if ($this->isactive) {
 536              return $this;
 537          } else {
 538              foreach ($this->children as &$child) {
 539                  $outcome = $child->find_active_node();
 540                  if ($outcome !== false) {
 541                      return $outcome;
 542                  }
 543              }
 544          }
 545          return false;
 546      }
 547  
 548      /**
 549       * Searches all children for the best matching active node
 550       * @return navigation_node|false
 551       */
 552      public function search_for_active_node() {
 553          if ($this->check_if_active(URL_MATCH_BASE)) {
 554              return $this;
 555          } else {
 556              foreach ($this->children as &$child) {
 557                  $outcome = $child->search_for_active_node();
 558                  if ($outcome !== false) {
 559                      return $outcome;
 560                  }
 561              }
 562          }
 563          return false;
 564      }
 565  
 566      /**
 567       * Gets the content for this node.
 568       *
 569       * @param bool $shorttext If true shorttext is used rather than the normal text
 570       * @return string
 571       */
 572      public function get_content($shorttext=false) {
 573          if ($shorttext && $this->shorttext!==null) {
 574              return format_string($this->shorttext);
 575          } else {
 576              return format_string($this->text);
 577          }
 578      }
 579  
 580      /**
 581       * Gets the title to use for this node.
 582       *
 583       * @return string
 584       */
 585      public function get_title() {
 586          if ($this->forcetitle || $this->action != null){
 587              return $this->title;
 588          } else {
 589              return '';
 590          }
 591      }
 592  
 593      /**
 594       * Gets the CSS class to add to this node to describe its type
 595       *
 596       * @return string
 597       */
 598      public function get_css_type() {
 599          if (array_key_exists($this->type, $this->namedtypes)) {
 600              return 'type_'.$this->namedtypes[$this->type];
 601          }
 602          return 'type_unknown';
 603      }
 604  
 605      /**
 606       * Finds all nodes that are expandable by AJAX
 607       *
 608       * @param array $expandable An array by reference to populate with expandable nodes.
 609       */
 610      public function find_expandable(array &$expandable) {
 611          foreach ($this->children as &$child) {
 612              if ($child->display && $child->has_children() && $child->children->count() == 0) {
 613                  $child->id = 'expandable_branch_'.$child->type.'_'.clean_param($child->key, PARAM_ALPHANUMEXT);
 614                  $this->add_class('canexpand');
 615                  $expandable[] = array('id' => $child->id, 'key' => $child->key, 'type' => $child->type);
 616              }
 617              $child->find_expandable($expandable);
 618          }
 619      }
 620  
 621      /**
 622       * Finds all nodes of a given type (recursive)
 623       *
 624       * @param int $type One of navigation_node::TYPE_*
 625       * @return array
 626       */
 627      public function find_all_of_type($type) {
 628          $nodes = $this->children->type($type);
 629          foreach ($this->children as &$node) {
 630              $childnodes = $node->find_all_of_type($type);
 631              $nodes = array_merge($nodes, $childnodes);
 632          }
 633          return $nodes;
 634      }
 635  
 636      /**
 637       * Removes this node if it is empty
 638       */
 639      public function trim_if_empty() {
 640          if ($this->children->count() == 0) {
 641              $this->remove();
 642          }
 643      }
 644  
 645      /**
 646       * Creates a tab representation of this nodes children that can be used
 647       * with print_tabs to produce the tabs on a page.
 648       *
 649       * call_user_func_array('print_tabs', $node->get_tabs_array());
 650       *
 651       * @param array $inactive
 652       * @param bool $return
 653       * @return array Array (tabs, selected, inactive, activated, return)
 654       */
 655      public function get_tabs_array(array $inactive=array(), $return=false) {
 656          $tabs = array();
 657          $rows = array();
 658          $selected = null;
 659          $activated = array();
 660          foreach ($this->children as $node) {
 661              $tabs[] = new tabobject($node->key, $node->action, $node->get_content(), $node->get_title());
 662              if ($node->contains_active_node()) {
 663                  if ($node->children->count() > 0) {
 664                      $activated[] = $node->key;
 665                      foreach ($node->children as $child) {
 666                          if ($child->contains_active_node()) {
 667                              $selected = $child->key;
 668                          }
 669                          $rows[] = new tabobject($child->key, $child->action, $child->get_content(), $child->get_title());
 670                      }
 671                  } else {
 672                      $selected = $node->key;
 673                  }
 674              }
 675          }
 676          return array(array($tabs, $rows), $selected, $inactive, $activated, $return);
 677      }
 678  
 679      /**
 680       * Sets the parent for this node and if this node is active ensures that the tree is properly
 681       * adjusted as well.
 682       *
 683       * @param navigation_node $parent
 684       */
 685      public function set_parent(navigation_node $parent) {
 686          // Set the parent (thats the easy part)
 687          $this->parent = $parent;
 688          // Check if this node is active (this is checked during construction)
 689          if ($this->isactive) {
 690              // Force all of the parent nodes open so you can see this node
 691              $this->parent->force_open();
 692              // Make all parents inactive so that its clear where we are.
 693              $this->parent->make_inactive();
 694          }
 695      }
 696  
 697      /**
 698       * Hides the node and any children it has.
 699       *
 700       * @since Moodle 2.5
 701       * @param array $typestohide Optional. An array of node types that should be hidden.
 702       *      If null all nodes will be hidden.
 703       *      If an array is given then nodes will only be hidden if their type mtatches an element in the array.
 704       *          e.g. array(navigation_node::TYPE_COURSE) would hide only course nodes.
 705       */
 706      public function hide(array $typestohide = null) {
 707          if ($typestohide === null || in_array($this->type, $typestohide)) {
 708              $this->display = false;
 709              if ($this->has_children()) {
 710                  foreach ($this->children as $child) {
 711                      $child->hide($typestohide);
 712                  }
 713              }
 714          }
 715      }
 716  }
 717  
 718  /**
 719   * Navigation node collection
 720   *
 721   * This class is responsible for managing a collection of navigation nodes.
 722   * It is required because a node's unique identifier is a combination of both its
 723   * key and its type.
 724   *
 725   * Originally an array was used with a string key that was a combination of the two
 726   * however it was decided that a better solution would be to use a class that
 727   * implements the standard IteratorAggregate interface.
 728   *
 729   * @package   core
 730   * @category  navigation
 731   * @copyright 2010 Sam Hemelryk
 732   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 733   */
 734  class navigation_node_collection implements IteratorAggregate {
 735      /**
 736       * A multidimensional array to where the first key is the type and the second
 737       * key is the nodes key.
 738       * @var array
 739       */
 740      protected $collection = array();
 741      /**
 742       * An array that contains references to nodes in the same order they were added.
 743       * This is maintained as a progressive array.
 744       * @var array
 745       */
 746      protected $orderedcollection = array();
 747      /**
 748       * A reference to the last node that was added to the collection
 749       * @var navigation_node
 750       */
 751      protected $last = null;
 752      /**
 753       * The total number of items added to this array.
 754       * @var int
 755       */
 756      protected $count = 0;
 757  
 758      /**
 759       * Adds a navigation node to the collection
 760       *
 761       * @param navigation_node $node Node to add
 762       * @param string $beforekey If specified, adds before a node with this key,
 763       *   otherwise adds at end
 764       * @return navigation_node Added node
 765       */
 766      public function add(navigation_node $node, $beforekey=null) {
 767          global $CFG;
 768          $key = $node->key;
 769          $type = $node->type;
 770  
 771          // First check we have a 2nd dimension for this type
 772          if (!array_key_exists($type, $this->orderedcollection)) {
 773              $this->orderedcollection[$type] = array();
 774          }
 775          // Check for a collision and report if debugging is turned on
 776          if ($CFG->debug && array_key_exists($key, $this->orderedcollection[$type])) {
 777              debugging('Navigation node intersect: Adding a node that already exists '.$key, DEBUG_DEVELOPER);
 778          }
 779  
 780          // Find the key to add before
 781          $newindex = $this->count;
 782          $last = true;
 783          if ($beforekey !== null) {
 784              foreach ($this->collection as $index => $othernode) {
 785                  if ($othernode->key === $beforekey) {
 786                      $newindex = $index;
 787                      $last = false;
 788                      break;
 789                  }
 790              }
 791              if ($newindex === $this->count) {
 792                  debugging('Navigation node add_before: Reference node not found ' . $beforekey .
 793                          ', options: ' . implode(' ', $this->get_key_list()), DEBUG_DEVELOPER);
 794              }
 795          }
 796  
 797          // Add the node to the appropriate place in the by-type structure (which
 798          // is not ordered, despite the variable name)
 799          $this->orderedcollection[$type][$key] = $node;
 800          if (!$last) {
 801              // Update existing references in the ordered collection (which is the
 802              // one that isn't called 'ordered') to shuffle them along if required
 803              for ($oldindex = $this->count; $oldindex > $newindex; $oldindex--) {
 804                  $this->collection[$oldindex] = $this->collection[$oldindex - 1];
 805              }
 806          }
 807          // Add a reference to the node to the progressive collection.
 808          $this->collection[$newindex] = $this->orderedcollection[$type][$key];
 809          // Update the last property to a reference to this new node.
 810          $this->last = $this->orderedcollection[$type][$key];
 811  
 812          // Reorder the array by index if needed
 813          if (!$last) {
 814              ksort($this->collection);
 815          }
 816          $this->count++;
 817          // Return the reference to the now added node
 818          return $node;
 819      }
 820  
 821      /**
 822       * Return a list of all the keys of all the nodes.
 823       * @return array the keys.
 824       */
 825      public function get_key_list() {
 826          $keys = array();
 827          foreach ($this->collection as $node) {
 828              $keys[] = $node->key;
 829          }
 830          return $keys;
 831      }
 832  
 833      /**
 834       * Fetches a node from this collection.
 835       *
 836       * @param string|int $key The key of the node we want to find.
 837       * @param int $type One of navigation_node::TYPE_*.
 838       * @return navigation_node|null
 839       */
 840      public function get($key, $type=null) {
 841          if ($type !== null) {
 842              // If the type is known then we can simply check and fetch
 843              if (!empty($this->orderedcollection[$type][$key])) {
 844                  return $this->orderedcollection[$type][$key];
 845              }
 846          } else {
 847              // Because we don't know the type we look in the progressive array
 848              foreach ($this->collection as $node) {
 849                  if ($node->key === $key) {
 850                      return $node;
 851                  }
 852              }
 853          }
 854          return false;
 855      }
 856  
 857      /**
 858       * Searches for a node with matching key and type.
 859       *
 860       * This function searches both the nodes in this collection and all of
 861       * the nodes in each collection belonging to the nodes in this collection.
 862       *
 863       * Recursive.
 864       *
 865       * @param string|int $key  The key of the node we want to find.
 866       * @param int $type  One of navigation_node::TYPE_*.
 867       * @return navigation_node|null
 868       */
 869      public function find($key, $type=null) {
 870          if ($type !== null && array_key_exists($type, $this->orderedcollection) && array_key_exists($key, $this->orderedcollection[$type])) {
 871              return $this->orderedcollection[$type][$key];
 872          } else {
 873              $nodes = $this->getIterator();
 874              // Search immediate children first
 875              foreach ($nodes as &$node) {
 876                  if ($node->key === $key && ($type === null || $type === $node->type)) {
 877                      return $node;
 878                  }
 879              }
 880              // Now search each childs children
 881              foreach ($nodes as &$node) {
 882                  $result = $node->children->find($key, $type);
 883                  if ($result !== false) {
 884                      return $result;
 885                  }
 886              }
 887          }
 888          return false;
 889      }
 890  
 891      /**
 892       * Fetches the last node that was added to this collection
 893       *
 894       * @return navigation_node
 895       */
 896      public function last() {
 897          return $this->last;
 898      }
 899  
 900      /**
 901       * Fetches all nodes of a given type from this collection
 902       *
 903       * @param string|int $type  node type being searched for.
 904       * @return array ordered collection
 905       */
 906      public function type($type) {
 907          if (!array_key_exists($type, $this->orderedcollection)) {
 908              $this->orderedcollection[$type] = array();
 909          }
 910          return $this->orderedcollection[$type];
 911      }
 912      /**
 913       * Removes the node with the given key and type from the collection
 914       *
 915       * @param string|int $key The key of the node we want to find.
 916       * @param int $type
 917       * @return bool
 918       */
 919      public function remove($key, $type=null) {
 920          $child = $this->get($key, $type);
 921          if ($child !== false) {
 922              foreach ($this->collection as $colkey => $node) {
 923                  if ($node->key === $key && $node->type == $type) {
 924                      unset($this->collection[$colkey]);
 925                      $this->collection = array_values($this->collection);
 926                      break;
 927                  }
 928              }
 929              unset($this->orderedcollection[$child->type][$child->key]);
 930              $this->count--;
 931              return true;
 932          }
 933          return false;
 934      }
 935  
 936      /**
 937       * Gets the number of nodes in this collection
 938       *
 939       * This option uses an internal count rather than counting the actual options to avoid
 940       * a performance hit through the count function.
 941       *
 942       * @return int
 943       */
 944      public function count() {
 945          return $this->count;
 946      }
 947      /**
 948       * Gets an array iterator for the collection.
 949       *
 950       * This is required by the IteratorAggregator interface and is used by routines
 951       * such as the foreach loop.
 952       *
 953       * @return ArrayIterator
 954       */
 955      public function getIterator() {
 956          return new ArrayIterator($this->collection);
 957      }
 958  }
 959  
 960  /**
 961   * The global navigation class used for... the global navigation
 962   *
 963   * This class is used by PAGE to store the global navigation for the site
 964   * and is then used by the settings nav and navbar to save on processing and DB calls
 965   *
 966   * See
 967   * {@link lib/pagelib.php} {@link moodle_page::initialise_theme_and_output()}
 968   * {@link lib/ajax/getnavbranch.php} Called by ajax
 969   *
 970   * @package   core
 971   * @category  navigation
 972   * @copyright 2009 Sam Hemelryk
 973   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 974   */
 975  class global_navigation extends navigation_node {
 976      /** @var moodle_page The Moodle page this navigation object belongs to. */
 977      protected $page;
 978      /** @var bool switch to let us know if the navigation object is initialised*/
 979      protected $initialised = false;
 980      /** @var array An array of course information */
 981      protected $mycourses = array();
 982      /** @var navigation_node[] An array for containing  root navigation nodes */
 983      protected $rootnodes = array();
 984      /** @var bool A switch for whether to show empty sections in the navigation */
 985      protected $showemptysections = true;
 986      /** @var bool A switch for whether courses should be shown within categories on the navigation. */
 987      protected $showcategories = null;
 988      /** @var null@var bool A switch for whether or not to show categories in the my courses branch. */
 989      protected $showmycategories = null;
 990      /** @var array An array of stdClasses for users that the navigation is extended for */
 991      protected $extendforuser = array();
 992      /** @var navigation_cache */
 993      protected $cache;
 994      /** @var array An array of course ids that are present in the navigation */
 995      protected $addedcourses = array();
 996      /** @var bool */
 997      protected $allcategoriesloaded = false;
 998      /** @var array An array of category ids that are included in the navigation */
 999      protected $addedcategories = array();
1000      /** @var int expansion limit */
1001      protected $expansionlimit = 0;
1002      /** @var int userid to allow parent to see child's profile page navigation */
1003      protected $useridtouseforparentchecks = 0;
1004      /** @var cache_session A cache that stores information on expanded courses */
1005      protected $cacheexpandcourse = null;
1006  
1007      /** Used when loading categories to load all top level categories [parent = 0] **/
1008      const LOAD_ROOT_CATEGORIES = 0;
1009      /** Used when loading categories to load all categories **/
1010      const LOAD_ALL_CATEGORIES = -1;
1011  
1012      /**
1013       * Constructs a new global navigation
1014       *
1015       * @param moodle_page $page The page this navigation object belongs to
1016       */
1017      public function __construct(moodle_page $page) {
1018          global $CFG, $SITE, $USER;
1019  
1020          if (during_initial_install()) {
1021              return;
1022          }
1023  
1024          if (get_home_page() == HOMEPAGE_SITE) {
1025              // We are using the site home for the root element
1026              $properties = array(
1027                  'key' => 'home',
1028                  'type' => navigation_node::TYPE_SYSTEM,
1029                  'text' => get_string('home'),
1030                  'action' => new moodle_url('/')
1031              );
1032          } else {
1033              // We are using the users my moodle for the root element
1034              $properties = array(
1035                  'key' => 'myhome',
1036                  'type' => navigation_node::TYPE_SYSTEM,
1037                  'text' => get_string('myhome'),
1038                  'action' => new moodle_url('/my/')
1039              );
1040          }
1041  
1042          // Use the parents constructor.... good good reuse
1043          parent::__construct($properties);
1044  
1045          // Initalise and set defaults
1046          $this->page = $page;
1047          $this->forceopen = true;
1048          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
1049      }
1050  
1051      /**
1052       * Mutator to set userid to allow parent to see child's profile
1053       * page navigation. See MDL-25805 for initial issue. Linked to it
1054       * is an issue explaining why this is a REALLY UGLY HACK thats not
1055       * for you to use!
1056       *
1057       * @param int $userid userid of profile page that parent wants to navigate around.
1058       */
1059      public function set_userid_for_parent_checks($userid) {
1060          $this->useridtouseforparentchecks = $userid;
1061      }
1062  
1063  
1064      /**
1065       * Initialises the navigation object.
1066       *
1067       * This causes the navigation object to look at the current state of the page
1068       * that it is associated with and then load the appropriate content.
1069       *
1070       * This should only occur the first time that the navigation structure is utilised
1071       * which will normally be either when the navbar is called to be displayed or
1072       * when a block makes use of it.
1073       *
1074       * @return bool
1075       */
1076      public function initialise() {
1077          global $CFG, $SITE, $USER;
1078          // Check if it has already been initialised
1079          if ($this->initialised || during_initial_install()) {
1080              return true;
1081          }
1082          $this->initialised = true;
1083  
1084          // Set up the five base root nodes. These are nodes where we will put our
1085          // content and are as follows:
1086          // site: Navigation for the front page.
1087          // myprofile: User profile information goes here.
1088          // currentcourse: The course being currently viewed.
1089          // mycourses: The users courses get added here.
1090          // courses: Additional courses are added here.
1091          // users: Other users information loaded here.
1092          $this->rootnodes = array();
1093          if (get_home_page() == HOMEPAGE_SITE) {
1094              // The home element should be my moodle because the root element is the site
1095              if (isloggedin() && !isguestuser()) {  // Makes no sense if you aren't logged in
1096                  $this->rootnodes['home'] = $this->add(get_string('myhome'), new moodle_url('/my/'), self::TYPE_SETTING, null, 'home');
1097              }
1098          } else {
1099              // The home element should be the site because the root node is my moodle
1100              $this->rootnodes['home'] = $this->add(get_string('sitehome'), new moodle_url('/'), self::TYPE_SETTING, null, 'home');
1101              if (!empty($CFG->defaulthomepage) && ($CFG->defaulthomepage == HOMEPAGE_MY)) {
1102                  // We need to stop automatic redirection
1103                  $this->rootnodes['home']->action->param('redirect', '0');
1104              }
1105          }
1106          $this->rootnodes['site'] = $this->add_course($SITE);
1107          $this->rootnodes['myprofile'] = $this->add(get_string('myprofile'), null, self::TYPE_USER, null, 'myprofile');
1108          $this->rootnodes['currentcourse'] = $this->add(get_string('currentcourse'), null, self::TYPE_ROOTNODE, null, 'currentcourse');
1109          $this->rootnodes['mycourses'] = $this->add(get_string('mycourses'), new moodle_url('/my/'), self::TYPE_ROOTNODE, null, 'mycourses');
1110          $this->rootnodes['courses'] = $this->add(get_string('courses'), new moodle_url('/course/index.php'), self::TYPE_ROOTNODE, null, 'courses');
1111          $this->rootnodes['users'] = $this->add(get_string('users'), null, self::TYPE_ROOTNODE, null, 'users');
1112  
1113          // We always load the frontpage course to ensure it is available without
1114          // JavaScript enabled.
1115          $this->add_front_page_course_essentials($this->rootnodes['site'], $SITE);
1116          $this->load_course_sections($SITE, $this->rootnodes['site']);
1117  
1118          $course = $this->page->course;
1119  
1120          // $issite gets set to true if the current pages course is the sites frontpage course
1121          $issite = ($this->page->course->id == $SITE->id);
1122          // Determine if the user is enrolled in any course.
1123          $enrolledinanycourse = enrol_user_sees_own_courses();
1124  
1125          $this->rootnodes['currentcourse']->mainnavonly = true;
1126          if ($enrolledinanycourse) {
1127              $this->rootnodes['mycourses']->isexpandable = true;
1128              if ($CFG->navshowallcourses) {
1129                  // When we show all courses we need to show both the my courses and the regular courses branch.
1130                  $this->rootnodes['courses']->isexpandable = true;
1131              }
1132          } else {
1133              $this->rootnodes['courses']->isexpandable = true;
1134          }
1135  
1136          // Load the users enrolled courses if they are viewing the My Moodle page AND the admin has not
1137          // set that they wish to keep the My Courses branch collapsed by default.
1138          if (!empty($CFG->navexpandmycourses) && $this->rootnodes['mycourses']->isactive){
1139              $this->load_courses_enrolled();
1140          } else {
1141              $this->rootnodes['mycourses']->collapse = true;
1142              $this->rootnodes['mycourses']->make_inactive();
1143          }
1144  
1145          $canviewcourseprofile = true;
1146  
1147          // Next load context specific content into the navigation
1148          switch ($this->page->context->contextlevel) {
1149              case CONTEXT_SYSTEM :
1150                  // Nothing left to do here I feel.
1151                  break;
1152              case CONTEXT_COURSECAT :
1153                  // This is essential, we must load categories.
1154                  $this->load_all_categories($this->page->context->instanceid, true);
1155                  break;
1156              case CONTEXT_BLOCK :
1157              case CONTEXT_COURSE :
1158                  if ($issite) {
1159                      // Nothing left to do here.
1160                      break;
1161                  }
1162  
1163                  // Load the course associated with the current page into the navigation.
1164                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1165                  // If the course wasn't added then don't try going any further.
1166                  if (!$coursenode) {
1167                      $canviewcourseprofile = false;
1168                      break;
1169                  }
1170  
1171                  // If the user is not enrolled then we only want to show the
1172                  // course node and not populate it.
1173  
1174                  // Not enrolled, can't view, and hasn't switched roles
1175                  if (!can_access_course($course, null, '', true)) {
1176                      if ($coursenode->isexpandable === true) {
1177                          // Obviously the situation has changed, update the cache and adjust the node.
1178                          // This occurs if the user access to a course has been revoked (one way or another) after
1179                          // initially logging in for this session.
1180                          $this->get_expand_course_cache()->set($course->id, 1);
1181                          $coursenode->isexpandable = true;
1182                          $coursenode->nodetype = self::NODETYPE_BRANCH;
1183                      }
1184                      // Very ugly hack - do not force "parents" to enrol into course their child is enrolled in,
1185                      // this hack has been propagated from user/view.php to display the navigation node. (MDL-25805)
1186                      if (!$this->current_user_is_parent_role()) {
1187                          $coursenode->make_active();
1188                          $canviewcourseprofile = false;
1189                          break;
1190                      }
1191                  } else if ($coursenode->isexpandable === false) {
1192                      // Obviously the situation has changed, update the cache and adjust the node.
1193                      // This occurs if the user has been granted access to a course (one way or another) after initially
1194                      // logging in for this session.
1195                      $this->get_expand_course_cache()->set($course->id, 1);
1196                      $coursenode->isexpandable = true;
1197                      $coursenode->nodetype = self::NODETYPE_BRANCH;
1198                  }
1199  
1200                  // Add the essentials such as reports etc...
1201                  $this->add_course_essentials($coursenode, $course);
1202                  // Extend course navigation with it's sections/activities
1203                  $this->load_course_sections($course, $coursenode);
1204                  if (!$coursenode->contains_active_node() && !$coursenode->search_for_active_node()) {
1205                      $coursenode->make_active();
1206                  }
1207  
1208                  break;
1209              case CONTEXT_MODULE :
1210                  if ($issite) {
1211                      // If this is the site course then most information will have
1212                      // already been loaded.
1213                      // However we need to check if there is more content that can
1214                      // yet be loaded for the specific module instance.
1215                      $activitynode = $this->rootnodes['site']->find($this->page->cm->id, navigation_node::TYPE_ACTIVITY);
1216                      if ($activitynode) {
1217                          $this->load_activity($this->page->cm, $this->page->course, $activitynode);
1218                      }
1219                      break;
1220                  }
1221  
1222                  $course = $this->page->course;
1223                  $cm = $this->page->cm;
1224  
1225                  // Load the course associated with the page into the navigation
1226                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1227  
1228                  // If the course wasn't added then don't try going any further.
1229                  if (!$coursenode) {
1230                      $canviewcourseprofile = false;
1231                      break;
1232                  }
1233  
1234                  // If the user is not enrolled then we only want to show the
1235                  // course node and not populate it.
1236                  if (!can_access_course($course, null, '', true)) {
1237                      $coursenode->make_active();
1238                      $canviewcourseprofile = false;
1239                      break;
1240                  }
1241  
1242                  $this->add_course_essentials($coursenode, $course);
1243  
1244                  // Load the course sections into the page
1245                  $this->load_course_sections($course, $coursenode, null, $cm);
1246                  $activity = $coursenode->find($cm->id, navigation_node::TYPE_ACTIVITY);
1247                  if (!empty($activity)) {
1248                      // Finally load the cm specific navigaton information
1249                      $this->load_activity($cm, $course, $activity);
1250                      // Check if we have an active ndoe
1251                      if (!$activity->contains_active_node() && !$activity->search_for_active_node()) {
1252                          // And make the activity node active.
1253                          $activity->make_active();
1254                      }
1255                  }
1256                  break;
1257              case CONTEXT_USER :
1258                  if ($issite) {
1259                      // The users profile information etc is already loaded
1260                      // for the front page.
1261                      break;
1262                  }
1263                  $course = $this->page->course;
1264                  // Load the course associated with the user into the navigation
1265                  $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
1266  
1267                  // If the course wasn't added then don't try going any further.
1268                  if (!$coursenode) {
1269                      $canviewcourseprofile = false;
1270                      break;
1271                  }
1272  
1273                  // If the user is not enrolled then we only want to show the
1274                  // course node and not populate it.
1275                  if (!can_access_course($course, null, '', true)) {
1276                      $coursenode->make_active();
1277                      $canviewcourseprofile = false;
1278                      break;
1279                  }
1280                  $this->add_course_essentials($coursenode, $course);
1281                  $this->load_course_sections($course, $coursenode);
1282                  break;
1283          }
1284  
1285          // Load for the current user
1286          $this->load_for_user();
1287          if ($this->page->context->contextlevel >= CONTEXT_COURSE && $this->page->context->instanceid != $SITE->id && $canviewcourseprofile) {
1288              $this->load_for_user(null, true);
1289          }
1290          // Load each extending user into the navigation.
1291          foreach ($this->extendforuser as $user) {
1292              if ($user->id != $USER->id) {
1293                  $this->load_for_user($user);
1294              }
1295          }
1296  
1297          // Give the local plugins a chance to include some navigation if they want.
1298          foreach (core_component::get_plugin_list_with_file('local', 'lib.php', true) as $plugin => $file) {
1299              $function = "local_{$plugin}_extends_navigation";
1300              $oldfunction = "{$plugin}_extends_navigation";
1301              if (function_exists($function)) {
1302                  // This is the preferred function name as there is less chance of conflicts
1303                  $function($this);
1304              } else if (function_exists($oldfunction)) {
1305                  // We continue to support the old function name to ensure backwards compatibility
1306                  debugging("Deprecated local plugin navigation callback: Please rename '{$oldfunction}' to '{$function}'. Support for the old callback will be dropped after the release of 2.4", DEBUG_DEVELOPER);
1307                  $oldfunction($this);
1308              }
1309          }
1310  
1311          // Remove any empty root nodes
1312          foreach ($this->rootnodes as $node) {
1313              // Dont remove the home node
1314              /** @var navigation_node $node */
1315              if ($node->key !== 'home' && !$node->has_children() && !$node->isactive) {
1316                  $node->remove();
1317              }
1318          }
1319  
1320          if (!$this->contains_active_node()) {
1321              $this->search_for_active_node();
1322          }
1323  
1324          // If the user is not logged in modify the navigation structure as detailed
1325          // in {@link http://docs.moodle.org/dev/Navigation_2.0_structure}
1326          if (!isloggedin()) {
1327              $activities = clone($this->rootnodes['site']->children);
1328              $this->rootnodes['site']->remove();
1329              $children = clone($this->children);
1330              $this->children = new navigation_node_collection();
1331              foreach ($activities as $child) {
1332                  $this->children->add($child);
1333              }
1334              foreach ($children as $child) {
1335                  $this->children->add($child);
1336              }
1337          }
1338          return true;
1339      }
1340  
1341      /**
1342       * Returns true if the current user is a parent of the user being currently viewed.
1343       *
1344       * If the current user is not viewing another user, or if the current user does not hold any parent roles over the
1345       * other user being viewed this function returns false.
1346       * In order to set the user for whom we are checking against you must call {@link set_userid_for_parent_checks()}
1347       *
1348       * @since Moodle 2.4
1349       * @return bool
1350       */
1351      protected function current_user_is_parent_role() {
1352          global $USER, $DB;
1353          if ($this->useridtouseforparentchecks && $this->useridtouseforparentchecks != $USER->id) {
1354              $usercontext = context_user::instance($this->useridtouseforparentchecks, MUST_EXIST);
1355              if (!has_capability('moodle/user:viewdetails', $usercontext)) {
1356                  return false;
1357              }
1358              if ($DB->record_exists('role_assignments', array('userid' => $USER->id, 'contextid' => $usercontext->id))) {
1359                  return true;
1360              }
1361          }
1362          return false;
1363      }
1364  
1365      /**
1366       * Returns true if courses should be shown within categories on the navigation.
1367       *
1368       * @param bool $ismycourse Set to true if you are calculating this for a course.
1369       * @return bool
1370       */
1371      protected function show_categories($ismycourse = false) {
1372          global $CFG, $DB;
1373          if ($ismycourse) {
1374              return $this->show_my_categories();
1375          }
1376          if ($this->showcategories === null) {
1377              $show = false;
1378              if ($this->page->context->contextlevel == CONTEXT_COURSECAT) {
1379                  $show = true;
1380              } else if (!empty($CFG->navshowcategories) && $DB->count_records('course_categories') > 1) {
1381                  $show = true;
1382              }
1383              $this->showcategories = $show;
1384          }
1385          return $this->showcategories;
1386      }
1387  
1388      /**
1389       * Returns true if we should show categories in the My Courses branch.
1390       * @return bool
1391       */
1392      protected function show_my_categories() {
1393          global $CFG, $DB;
1394          if ($this->showmycategories === null) {
1395              $this->showmycategories = !empty($CFG->navshowmycoursecategories) && $DB->count_records('course_categories') > 1;
1396          }
1397          return $this->showmycategories;
1398      }
1399  
1400      /**
1401       * Loads the courses in Moodle into the navigation.
1402       *
1403       * @global moodle_database $DB
1404       * @param string|array $categoryids An array containing categories to load courses
1405       *                     for, OR null to load courses for all categories.
1406       * @return array An array of navigation_nodes one for each course
1407       */
1408      protected function load_all_courses($categoryids = null) {
1409          global $CFG, $DB, $SITE;
1410  
1411          // Work out the limit of courses.
1412          $limit = 20;
1413          if (!empty($CFG->navcourselimit)) {
1414              $limit = $CFG->navcourselimit;
1415          }
1416  
1417          $toload = (empty($CFG->navshowallcourses))?self::LOAD_ROOT_CATEGORIES:self::LOAD_ALL_CATEGORIES;
1418  
1419          // If we are going to show all courses AND we are showing categories then
1420          // to save us repeated DB calls load all of the categories now
1421          if ($this->show_categories()) {
1422              $this->load_all_categories($toload);
1423          }
1424  
1425          // Will be the return of our efforts
1426          $coursenodes = array();
1427  
1428          // Check if we need to show categories.
1429          if ($this->show_categories()) {
1430              // Hmmm we need to show categories... this is going to be painful.
1431              // We now need to fetch up to $limit courses for each category to
1432              // be displayed.
1433              if ($categoryids !== null) {
1434                  if (!is_array($categoryids)) {
1435                      $categoryids = array($categoryids);
1436                  }
1437                  list($categorywhere, $categoryparams) = $DB->get_in_or_equal($categoryids, SQL_PARAMS_NAMED, 'cc');
1438                  $categorywhere = 'WHERE cc.id '.$categorywhere;
1439              } else if ($toload == self::LOAD_ROOT_CATEGORIES) {
1440                  $categorywhere = 'WHERE cc.depth = 1 OR cc.depth = 2';
1441                  $categoryparams = array();
1442              } else {
1443                  $categorywhere = '';
1444                  $categoryparams = array();
1445              }
1446  
1447              // First up we are going to get the categories that we are going to
1448              // need so that we can determine how best to load the courses from them.
1449              $sql = "SELECT cc.id, COUNT(c.id) AS coursecount
1450                          FROM {course_categories} cc
1451                      LEFT JOIN {course} c ON c.category = cc.id
1452                              {$categorywhere}
1453                      GROUP BY cc.id";
1454              $categories = $DB->get_recordset_sql($sql, $categoryparams);
1455              $fullfetch = array();
1456              $partfetch = array();
1457              foreach ($categories as $category) {
1458                  if (!$this->can_add_more_courses_to_category($category->id)) {
1459                      continue;
1460                  }
1461                  if ($category->coursecount > $limit * 5) {
1462                      $partfetch[] = $category->id;
1463                  } else if ($category->coursecount > 0) {
1464                      $fullfetch[] = $category->id;
1465                  }
1466              }
1467              $categories->close();
1468  
1469              if (count($fullfetch)) {
1470                  // First up fetch all of the courses in categories where we know that we are going to
1471                  // need the majority of courses.
1472                  list($categoryids, $categoryparams) = $DB->get_in_or_equal($fullfetch, SQL_PARAMS_NAMED, 'lcategory');
1473                  $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1474                  $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1475                  $categoryparams['contextlevel'] = CONTEXT_COURSE;
1476                  $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1477                              FROM {course} c
1478                                  $ccjoin
1479                              WHERE c.category {$categoryids}
1480                          ORDER BY c.sortorder ASC";
1481                  $coursesrs = $DB->get_recordset_sql($sql, $categoryparams);
1482                  foreach ($coursesrs as $course) {
1483                      if ($course->id == $SITE->id) {
1484                          // This should not be necessary, frontpage is not in any category.
1485                          continue;
1486                      }
1487                      if (array_key_exists($course->id, $this->addedcourses)) {
1488                          // It is probably better to not include the already loaded courses
1489                          // directly in SQL because inequalities may confuse query optimisers
1490                          // and may interfere with query caching.
1491                          continue;
1492                      }
1493                      if (!$this->can_add_more_courses_to_category($course->category)) {
1494                          continue;
1495                      }
1496                      context_helper::preload_from_record($course);
1497                      if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1498                          continue;
1499                      }
1500                      $coursenodes[$course->id] = $this->add_course($course);
1501                  }
1502                  $coursesrs->close();
1503              }
1504  
1505              if (count($partfetch)) {
1506                  // Next we will work our way through the categories where we will likely only need a small
1507                  // proportion of the courses.
1508                  foreach ($partfetch as $categoryid) {
1509                      $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1510                      $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1511                      $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1512                                  FROM {course} c
1513                                      $ccjoin
1514                                  WHERE c.category = :categoryid
1515                              ORDER BY c.sortorder ASC";
1516                      $courseparams = array('categoryid' => $categoryid, 'contextlevel' => CONTEXT_COURSE);
1517                      $coursesrs = $DB->get_recordset_sql($sql, $courseparams, 0, $limit * 5);
1518                      foreach ($coursesrs as $course) {
1519                          if ($course->id == $SITE->id) {
1520                              // This should not be necessary, frontpage is not in any category.
1521                              continue;
1522                          }
1523                          if (array_key_exists($course->id, $this->addedcourses)) {
1524                              // It is probably better to not include the already loaded courses
1525                              // directly in SQL because inequalities may confuse query optimisers
1526                              // and may interfere with query caching.
1527                              // This also helps to respect expected $limit on repeated executions.
1528                              continue;
1529                          }
1530                          if (!$this->can_add_more_courses_to_category($course->category)) {
1531                              break;
1532                          }
1533                          context_helper::preload_from_record($course);
1534                          if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1535                              continue;
1536                          }
1537                          $coursenodes[$course->id] = $this->add_course($course);
1538                      }
1539                      $coursesrs->close();
1540                  }
1541              }
1542          } else {
1543              // Prepare the SQL to load the courses and their contexts
1544              list($courseids, $courseparams) = $DB->get_in_or_equal(array_keys($this->addedcourses), SQL_PARAMS_NAMED, 'lc', false);
1545              $ccselect = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1546              $ccjoin = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1547              $courseparams['contextlevel'] = CONTEXT_COURSE;
1548              $sql = "SELECT c.id, c.sortorder, c.visible, c.fullname, c.shortname, c.category $ccselect
1549                          FROM {course} c
1550                              $ccjoin
1551                          WHERE c.id {$courseids}
1552                      ORDER BY c.sortorder ASC";
1553              $coursesrs = $DB->get_recordset_sql($sql, $courseparams);
1554              foreach ($coursesrs as $course) {
1555                  if ($course->id == $SITE->id) {
1556                      // frotpage is not wanted here
1557                      continue;
1558                  }
1559                  if ($this->page->course && ($this->page->course->id == $course->id)) {
1560                      // Don't include the currentcourse in this nodelist - it's displayed in the Current course node
1561                      continue;
1562                  }
1563                  context_helper::preload_from_record($course);
1564                  if (!$course->visible && !is_role_switched($course->id) && !has_capability('moodle/course:viewhiddencourses', context_course::instance($course->id))) {
1565                      continue;
1566                  }
1567                  $coursenodes[$course->id] = $this->add_course($course);
1568                  if (count($coursenodes) >= $limit) {
1569                      break;
1570                  }
1571              }
1572              $coursesrs->close();
1573          }
1574  
1575          return $coursenodes;
1576      }
1577  
1578      /**
1579       * Returns true if more courses can be added to the provided category.
1580       *
1581       * @param int|navigation_node|stdClass $category
1582       * @return bool
1583       */
1584      protected function can_add_more_courses_to_category($category) {
1585          global $CFG;
1586          $limit = 20;
1587          if (!empty($CFG->navcourselimit)) {
1588              $limit = (int)$CFG->navcourselimit;
1589          }
1590          if (is_numeric($category)) {
1591              if (!array_key_exists($category, $this->addedcategories)) {
1592                  return true;
1593              }
1594              $coursecount = count($this->addedcategories[$category]->children->type(self::TYPE_COURSE));
1595          } else if ($category instanceof navigation_node) {
1596              if (($category->type != self::TYPE_CATEGORY) || ($category->type != self::TYPE_MY_CATEGORY)) {
1597                  return false;
1598              }
1599              $coursecount = count($category->children->type(self::TYPE_COURSE));
1600          } else if (is_object($category) && property_exists($category,'id')) {
1601              $coursecount = count($this->addedcategories[$category->id]->children->type(self::TYPE_COURSE));
1602          }
1603          return ($coursecount <= $limit);
1604      }
1605  
1606      /**
1607       * Loads all categories (top level or if an id is specified for that category)
1608       *
1609       * @param int $categoryid The category id to load or null/0 to load all base level categories
1610       * @param bool $showbasecategories If set to true all base level categories will be loaded as well
1611       *        as the requested category and any parent categories.
1612       * @return navigation_node|void returns a navigation node if a category has been loaded.
1613       */
1614      protected function load_all_categories($categoryid = self::LOAD_ROOT_CATEGORIES, $showbasecategories = false) {
1615          global $CFG, $DB;
1616  
1617          // Check if this category has already been loaded
1618          if ($this->allcategoriesloaded || ($categoryid < 1 && $this->is_category_fully_loaded($categoryid))) {
1619              return true;
1620          }
1621  
1622          $catcontextsql = context_helper::get_preload_record_columns_sql('ctx');
1623          $sqlselect = "SELECT cc.*, $catcontextsql
1624                        FROM {course_categories} cc
1625                        JOIN {context} ctx ON cc.id = ctx.instanceid";
1626          $sqlwhere = "WHERE ctx.contextlevel = ".CONTEXT_COURSECAT;
1627          $sqlorder = "ORDER BY cc.depth ASC, cc.sortorder ASC, cc.id ASC";
1628          $params = array();
1629  
1630          $categoriestoload = array();
1631          if ($categoryid == self::LOAD_ALL_CATEGORIES) {
1632              // We are going to load all categories regardless... prepare to fire
1633              // on the database server!
1634          } else if ($categoryid == self::LOAD_ROOT_CATEGORIES) { // can be 0
1635              // We are going to load all of the first level categories (categories without parents)
1636              $sqlwhere .= " AND cc.parent = 0";
1637          } else if (array_key_exists($categoryid, $this->addedcategories)) {
1638              // The category itself has been loaded already so we just need to ensure its subcategories
1639              // have been loaded
1640              $addedcategories = $this->addedcategories;
1641              unset($addedcategories[$categoryid]);
1642              if (count($addedcategories) > 0) {
1643                  list($sql, $params) = $DB->get_in_or_equal(array_keys($addedcategories), SQL_PARAMS_NAMED, 'parent', false);
1644                  if ($showbasecategories) {
1645                      // We need to include categories with parent = 0 as well
1646                      $sqlwhere .= " AND (cc.parent = :categoryid OR cc.parent = 0) AND cc.parent {$sql}";
1647                  } else {
1648                      // All we need is categories that match the parent
1649                      $sqlwhere .= " AND cc.parent = :categoryid AND cc.parent {$sql}";
1650                  }
1651              }
1652              $params['categoryid'] = $categoryid;
1653          } else {
1654              // This category hasn't been loaded yet so we need to fetch it, work out its category path
1655              // and load this category plus all its parents and subcategories
1656              $category = $DB->get_record('course_categories', array('id' => $categoryid), 'path', MUST_EXIST);
1657              $categoriestoload = explode('/', trim($category->path, '/'));
1658              list($select, $params) = $DB->get_in_or_equal($categoriestoload);
1659              // We are going to use select twice so double the params
1660              $params = array_merge($params, $params);
1661              $basecategorysql = ($showbasecategories)?' OR cc.depth = 1':'';
1662              $sqlwhere .= " AND (cc.id {$select} OR cc.parent {$select}{$basecategorysql})";
1663          }
1664  
1665          $categoriesrs = $DB->get_recordset_sql("$sqlselect $sqlwhere $sqlorder", $params);
1666          $categories = array();
1667          foreach ($categoriesrs as $category) {
1668              // Preload the context.. we'll need it when adding the category in order
1669              // to format the category name.
1670              context_helper::preload_from_record($category);
1671              if (array_key_exists($category->id, $this->addedcategories)) {
1672                  // Do nothing, its already been added.
1673              } else if ($category->parent == '0') {
1674                  // This is a root category lets add it immediately
1675                  $this->add_category($category, $this->rootnodes['courses']);
1676              } else if (array_key_exists($category->parent, $this->addedcategories)) {
1677                  // This categories parent has already been added we can add this immediately
1678                  $this->add_category($category, $this->addedcategories[$category->parent]);
1679              } else {
1680                  $categories[] = $category;
1681              }
1682          }
1683          $categoriesrs->close();
1684  
1685          // Now we have an array of categories we need to add them to the navigation.
1686          while (!empty($categories)) {
1687              $category = reset($categories);
1688              if (array_key_exists($category->id, $this->addedcategories)) {
1689                  // Do nothing
1690              } else if ($category->parent == '0') {
1691                  $this->add_category($category, $this->rootnodes['courses']);
1692              } else if (array_key_exists($category->parent, $this->addedcategories)) {
1693                  $this->add_category($category, $this->addedcategories[$category->parent]);
1694              } else {
1695                  // This category isn't in the navigation and niether is it's parent (yet).
1696                  // We need to go through the category path and add all of its components in order.
1697                  $path = explode('/', trim($category->path, '/'));
1698                  foreach ($path as $catid) {
1699                      if (!array_key_exists($catid, $this->addedcategories)) {
1700                          // This category isn't in the navigation yet so add it.
1701                          $subcategory = $categories[$catid];
1702                          if ($subcategory->parent == '0') {
1703                              // Yay we have a root category - this likely means we will now be able
1704                              // to add categories without problems.
1705                              $this->add_category($subcategory, $this->rootnodes['courses']);
1706                          } else if (array_key_exists($subcategory->parent, $this->addedcategories)) {
1707                              // The parent is in the category (as we'd expect) so add it now.
1708                              $this->add_category($subcategory, $this->addedcategories[$subcategory->parent]);
1709                              // Remove the category from the categories array.
1710                              unset($categories[$catid]);
1711                          } else {
1712                              // We should never ever arrive here - if we have then there is a bigger
1713                              // problem at hand.
1714                              throw new coding_exception('Category path order is incorrect and/or there are missing categories');
1715                          }
1716                      }
1717                  }
1718              }
1719              // Remove the category from the categories array now that we know it has been added.
1720              unset($categories[$category->id]);
1721          }
1722          if ($categoryid === self::LOAD_ALL_CATEGORIES) {
1723              $this->allcategoriesloaded = true;
1724          }
1725          // Check if there are any categories to load.
1726          if (count($categoriestoload) > 0) {
1727              $readytoloadcourses = array();
1728              foreach ($categoriestoload as $category) {
1729                  if ($this->can_add_more_courses_to_category($category)) {
1730                      $readytoloadcourses[] = $category;
1731                  }
1732              }
1733              if (count($readytoloadcourses)) {
1734                  $this->load_all_courses($readytoloadcourses);
1735              }
1736          }
1737  
1738          // Look for all categories which have been loaded
1739          if (!empty($this->addedcategories)) {
1740              $categoryids = array();
1741              foreach ($this->addedcategories as $category) {
1742                  if ($this->can_add_more_courses_to_category($category)) {
1743                      $categoryids[] = $category->key;
1744                  }
1745              }
1746              if ($categoryids) {
1747                  list($categoriessql, $params) = $DB->get_in_or_equal($categoryids, SQL_PARAMS_NAMED);
1748                  $params['limit'] = (!empty($CFG->navcourselimit))?$CFG->navcourselimit:20;
1749                  $sql = "SELECT cc.id, COUNT(c.id) AS coursecount
1750                            FROM {course_categories} cc
1751                            JOIN {course} c ON c.category = cc.id
1752                           WHERE cc.id {$categoriessql}
1753                        GROUP BY cc.id
1754                          HAVING COUNT(c.id) > :limit";
1755                  $excessivecategories = $DB->get_records_sql($sql, $params);
1756                  foreach ($categories as &$category) {
1757                      if (array_key_exists($category->key, $excessivecategories) && !$this->can_add_more_courses_to_category($category)) {
1758                          $url = new moodle_url('/course/index.php', array('categoryid' => $category->key));
1759                          $category->add(get_string('viewallcourses'), $url, self::TYPE_SETTING);
1760                      }
1761                  }
1762              }
1763          }
1764      }
1765  
1766      /**
1767       * Adds a structured category to the navigation in the correct order/place
1768       *
1769       * @param stdClass $category category to be added in navigation.
1770       * @param navigation_node $parent parent navigation node
1771       * @param int $nodetype type of node, if category is under MyHome then it's TYPE_MY_CATEGORY
1772       * @return void.
1773       */
1774      protected function add_category(stdClass $category, navigation_node $parent, $nodetype = self::TYPE_CATEGORY) {
1775          if (array_key_exists($category->id, $this->addedcategories)) {
1776              return;
1777          }
1778          $url = new moodle_url('/course/index.php', array('categoryid' => $category->id));
1779          $context = context_coursecat::instance($category->id);
1780          $categoryname = format_string($category->name, true, array('context' => $context));
1781          $categorynode = $parent->add($categoryname, $url, $nodetype, $categoryname, $category->id);
1782          if (empty($category->visible)) {
1783              if (has_capability('moodle/category:viewhiddencategories', context_system::instance())) {
1784                  $categorynode->hidden = true;
1785              } else {
1786                  $categorynode->display = false;
1787              }
1788          }
1789          $this->addedcategories[$category->id] = $categorynode;
1790      }
1791  
1792      /**
1793       * Loads the given course into the navigation
1794       *
1795       * @param stdClass $course
1796       * @return navigation_node
1797       */
1798      protected function load_course(stdClass $course) {
1799          global $SITE;
1800          if ($course->id == $SITE->id) {
1801              // This is always loaded during initialisation
1802              return $this->rootnodes['site'];
1803          } else if (array_key_exists($course->id, $this->addedcourses)) {
1804              // The course has already been loaded so return a reference
1805              return $this->addedcourses[$course->id];
1806          } else {
1807              // Add the course
1808              return $this->add_course($course);
1809          }
1810      }
1811  
1812      /**
1813       * Loads all of the courses section into the navigation.
1814       *
1815       * This function calls method from current course format, see
1816       * {@link format_base::extend_course_navigation()}
1817       * If course module ($cm) is specified but course format failed to create the node,
1818       * the activity node is created anyway.
1819       *
1820       * By default course formats call the method {@link global_navigation::load_generic_course_sections()}
1821       *
1822       * @param stdClass $course Database record for the course
1823       * @param navigation_node $coursenode The course node within the navigation
1824       * @param null|int $sectionnum If specified load the contents of section with this relative number
1825       * @param null|cm_info $cm If specified make sure that activity node is created (either
1826       *    in containg section or by calling load_stealth_activity() )
1827       */
1828      protected function load_course_sections(stdClass $course, navigation_node $coursenode, $sectionnum = null, $cm = null) {
1829          global $CFG, $SITE;
1830          require_once($CFG->dirroot.'/course/lib.php');
1831          if (isset($cm->sectionnum)) {
1832              $sectionnum = $cm->sectionnum;
1833          }
1834          if ($sectionnum !== null) {
1835              $this->includesectionnum = $sectionnum;
1836          }
1837          course_get_format($course)->extend_course_navigation($this, $coursenode, $sectionnum, $cm);
1838          if (isset($cm->id)) {
1839              $activity = $coursenode->find($cm->id, self::TYPE_ACTIVITY);
1840              if (empty($activity)) {
1841                  $activity = $this->load_stealth_activity($coursenode, get_fast_modinfo($course));
1842              }
1843          }
1844     }
1845  
1846      /**
1847       * Generates an array of sections and an array of activities for the given course.
1848       *
1849       * This method uses the cache to improve performance and avoid the get_fast_modinfo call
1850       *
1851       * @param stdClass $course
1852       * @return array Array($sections, $activities)
1853       */
1854      protected function generate_sections_and_activities(stdClass $course) {
1855          global $CFG;
1856          require_once($CFG->dirroot.'/course/lib.php');
1857  
1858          $modinfo = get_fast_modinfo($course);
1859          $sections = $modinfo->get_section_info_all();
1860  
1861          // For course formats using 'numsections' trim the sections list
1862          $courseformatoptions = course_get_format($course)->get_format_options();
1863          if (isset($courseformatoptions['numsections'])) {
1864              $sections = array_slice($sections, 0, $courseformatoptions['numsections']+1, true);
1865          }
1866  
1867          $activities = array();
1868  
1869          foreach ($sections as $key => $section) {
1870              // Clone and unset summary to prevent $SESSION bloat (MDL-31802).
1871              $sections[$key] = clone($section);
1872              unset($sections[$key]->summary);
1873              $sections[$key]->hasactivites = false;
1874              if (!array_key_exists($section->section, $modinfo->sections)) {
1875                  continue;
1876              }
1877              foreach ($modinfo->sections[$section->section] as $cmid) {
1878                  $cm = $modinfo->cms[$cmid];
1879                  $activity = new stdClass;
1880                  $activity->id = $cm->id;
1881                  $activity->course = $course->id;
1882                  $activity->section = $section->section;
1883                  $activity->name = $cm->name;
1884                  $activity->icon = $cm->icon;
1885                  $activity->iconcomponent = $cm->iconcomponent;
1886                  $activity->hidden = (!$cm->visible);
1887                  $activity->modname = $cm->modname;
1888                  $activity->nodetype = navigation_node::NODETYPE_LEAF;
1889                  $activity->onclick = $cm->onclick;
1890                  $url = $cm->url;
1891                  if (!$url) {
1892                      $activity->url = null;
1893                      $activity->display = false;
1894                  } else {
1895                      $activity->url = $url->out();
1896                      $activity->display = $cm->uservisible ? true : false;
1897                      if (self::module_extends_navigation($cm->modname)) {
1898                          $activity->nodetype = navigation_node::NODETYPE_BRANCH;
1899                      }
1900                  }
1901                  $activities[$cmid] = $activity;
1902                  if ($activity->display) {
1903                      $sections[$key]->hasactivites = true;
1904                  }
1905              }
1906          }
1907  
1908          return array($sections, $activities);
1909      }
1910  
1911      /**
1912       * Generically loads the course sections into the course's navigation.
1913       *
1914       * @param stdClass $course
1915       * @param navigation_node $coursenode
1916       * @return array An array of course section nodes
1917       */
1918      public function load_generic_course_sections(stdClass $course, navigation_node $coursenode) {
1919          global $CFG, $DB, $USER, $SITE;
1920          require_once($CFG->dirroot.'/course/lib.php');
1921  
1922          list($sections, $activities) = $this->generate_sections_and_activities($course);
1923  
1924          $navigationsections = array();
1925          foreach ($sections as $sectionid => $section) {
1926              $section = clone($section);
1927              if ($course->id == $SITE->id) {
1928                  $this->load_section_activities($coursenode, $section->section, $activities);
1929              } else {
1930                  if (!$section->uservisible || (!$this->showemptysections &&
1931                          !$section->hasactivites && $this->includesectionnum !== $section->section)) {
1932                      continue;
1933                  }
1934  
1935                  $sectionname = get_section_name($course, $section);
1936                  $url = course_get_url($course, $section->section, array('navigation' => true));
1937  
1938                  $sectionnode = $coursenode->add($sectionname, $url, navigation_node::TYPE_SECTION, null, $section->id);
1939                  $sectionnode->nodetype = navigation_node::NODETYPE_BRANCH;
1940                  $sectionnode->hidden = (!$section->visible || !$section->available);
1941                  if ($this->includesectionnum !== false && $this->includesectionnum == $section->section) {
1942                      $this->load_section_activities($sectionnode, $section->section, $activities);
1943                  }
1944                  $section->sectionnode = $sectionnode;
1945                  $navigationsections[$sectionid] = $section;
1946              }
1947          }
1948          return $navigationsections;
1949      }
1950  
1951      /**
1952       * Loads all of the activities for a section into the navigation structure.
1953       *
1954       * @param navigation_node $sectionnode
1955       * @param int $sectionnumber
1956       * @param array $activities An array of activites as returned by {@link global_navigation::generate_sections_and_activities()}
1957       * @param stdClass $course The course object the section and activities relate to.
1958       * @return array Array of activity nodes
1959       */
1960      protected function load_section_activities(navigation_node $sectionnode, $sectionnumber, array $activities, $course = null) {
1961          global $CFG, $SITE;
1962          // A static counter for JS function naming
1963          static $legacyonclickcounter = 0;
1964  
1965          $activitynodes = array();
1966          if (empty($activities)) {
1967              return $activitynodes;
1968          }
1969  
1970          if (!is_object($course)) {
1971              $activity = reset($activities);
1972              $courseid = $activity->course;
1973          } else {
1974              $courseid = $course->id;
1975          }
1976          $showactivities = ($courseid != $SITE->id || !empty($CFG->navshowfrontpagemods));
1977  
1978          foreach ($activities as $activity) {
1979              if ($activity->section != $sectionnumber) {
1980                  continue;
1981              }
1982              if ($activity->icon) {
1983                  $icon = new pix_icon($activity->icon, get_string('modulename', $activity->modname), $activity->iconcomponent);
1984              } else {
1985                  $icon = new pix_icon('icon', get_string('modulename', $activity->modname), $activity->modname);
1986              }
1987  
1988              // Prepare the default name and url for the node
1989              $activityname = format_string($activity->name, true, array('context' => context_module::instance($activity->id)));
1990              $action = new moodle_url($activity->url);
1991  
1992              // Check if the onclick property is set (puke!)
1993              if (!empty($activity->onclick)) {
1994                  // Increment the counter so that we have a unique number.
1995                  $legacyonclickcounter++;
1996                  // Generate the function name we will use
1997                  $functionname = 'legacy_activity_onclick_handler_'.$legacyonclickcounter;
1998                  $propogrationhandler = '';
1999                  // Check if we need to cancel propogation. Remember inline onclick
2000                  // events would return false if they wanted to prevent propogation and the
2001                  // default action.
2002                  if (strpos($activity->onclick, 'return false')) {
2003                      $propogrationhandler = 'e.halt();';
2004                  }
2005                  // Decode the onclick - it has already been encoded for display (puke)
2006                  $onclick = htmlspecialchars_decode($activity->onclick, ENT_QUOTES);
2007                  // Build the JS function the click event will call
2008                  $jscode = "function {$functionname}(e) { $propogrationhandler $onclick }";
2009                  $this->page->requires->js_init_code($jscode);
2010                  // Override the default url with the new action link
2011                  $action = new action_link($action, $activityname, new component_action('click', $functionname));
2012              }
2013  
2014              $activitynode = $sectionnode->add($activityname, $action, navigation_node::TYPE_ACTIVITY, null, $activity->id, $icon);
2015              $activitynode->title(get_string('modulename', $activity->modname));
2016              $activitynode->hidden = $activity->hidden;
2017              $activitynode->display = $showactivities && $activity->display;
2018              $activitynode->nodetype = $activity->nodetype;
2019              $activitynodes[$activity->id] = $activitynode;
2020          }
2021  
2022          return $activitynodes;
2023      }
2024      /**
2025       * Loads a stealth module from unavailable section
2026       * @param navigation_node $coursenode
2027       * @param stdClass $modinfo
2028       * @return navigation_node or null if not accessible
2029       */
2030      protected function load_stealth_activity(navigation_node $coursenode, $modinfo) {
2031          if (empty($modinfo->cms[$this->page->cm->id])) {
2032              return null;
2033          }
2034          $cm = $modinfo->cms[$this->page->cm->id];
2035          if ($cm->icon) {
2036              $icon = new pix_icon($cm->icon, get_string('modulename', $cm->modname), $cm->iconcomponent);
2037          } else {
2038              $icon = new pix_icon('icon', get_string('modulename', $cm->modname), $cm->modname);
2039          }
2040          $url = $cm->url;
2041          $activitynode = $coursenode->add(format_string($cm->name), $url, navigation_node::TYPE_ACTIVITY, null, $cm->id, $icon);
2042          $activitynode->title(get_string('modulename', $cm->modname));
2043          $activitynode->hidden = (!$cm->visible);
2044          if (!$cm->uservisible) {
2045              // Do not show any error here, let the page handle exception that activity is not visible for the current user.
2046              // Also there may be no exception at all in case when teacher is logged in as student.
2047              $activitynode->display = false;
2048          } else if (!$url) {
2049              // Don't show activities that don't have links!
2050              $activitynode->display = false;
2051          } else if (self::module_extends_navigation($cm->modname)) {
2052              $activitynode->nodetype = navigation_node::NODETYPE_BRANCH;
2053          }
2054          return $activitynode;
2055      }
2056      /**
2057       * Loads the navigation structure for the given activity into the activities node.
2058       *
2059       * This method utilises a callback within the modules lib.php file to load the
2060       * content specific to activity given.
2061       *
2062       * The callback is a method: {modulename}_extend_navigation()
2063       * Examples:
2064       *  * {@link forum_extend_navigation()}
2065       *  * {@link workshop_extend_navigation()}
2066       *
2067       * @param cm_info|stdClass $cm
2068       * @param stdClass $course
2069       * @param navigation_node $activity
2070       * @return bool
2071       */
2072      protected function load_activity($cm, stdClass $course, navigation_node $activity) {
2073          global $CFG, $DB;
2074  
2075          // make sure we have a $cm from get_fast_modinfo as this contains activity access details
2076          if (!($cm instanceof cm_info)) {
2077              $modinfo = get_fast_modinfo($course);
2078              $cm = $modinfo->get_cm($cm->id);
2079          }
2080          $activity->nodetype = navigation_node::NODETYPE_LEAF;
2081          $activity->make_active();
2082          $file = $CFG->dirroot.'/mod/'.$cm->modname.'/lib.php';
2083          $function = $cm->modname.'_extend_navigation';
2084  
2085          if (file_exists($file)) {
2086              require_once($file);
2087              if (function_exists($function)) {
2088                  $activtyrecord = $DB->get_record($cm->modname, array('id' => $cm->instance), '*', MUST_EXIST);
2089                  $function($activity, $course, $activtyrecord, $cm);
2090              }
2091          }
2092  
2093          // Allow the active advanced grading method plugin to append module navigation
2094          $featuresfunc = $cm->modname.'_supports';
2095          if (function_exists($featuresfunc) && $featuresfunc(FEATURE_ADVANCED_GRADING)) {
2096              require_once($CFG->dirroot.'/grade/grading/lib.php');
2097              $gradingman = get_grading_manager($cm->context,  'mod_'.$cm->modname);
2098              $gradingman->extend_navigation($this, $activity);
2099          }
2100  
2101          return $activity->has_children();
2102      }
2103      /**
2104       * Loads user specific information into the navigation in the appropriate place.
2105       *
2106       * If no user is provided the current user is assumed.
2107       *
2108       * @param stdClass $user
2109       * @param bool $forceforcontext probably force something to be loaded somewhere (ask SamH if not sure what this means)
2110       * @return bool
2111       */
2112      protected function load_for_user($user=null, $forceforcontext=false) {
2113          global $DB, $CFG, $USER, $SITE;
2114  
2115          if ($user === null) {
2116              // We can't require login here but if the user isn't logged in we don't
2117              // want to show anything
2118              if (!isloggedin() || isguestuser()) {
2119                  return false;
2120              }
2121              $user = $USER;
2122          } else if (!is_object($user)) {
2123              // If the user is not an object then get them from the database
2124              $select = context_helper::get_preload_record_columns_sql('ctx');
2125              $sql = "SELECT u.*, $select
2126                        FROM {user} u
2127                        JOIN {context} ctx ON u.id = ctx.instanceid
2128                       WHERE u.id = :userid AND
2129                             ctx.contextlevel = :contextlevel";
2130              $user = $DB->get_record_sql($sql, array('userid' => (int)$user, 'contextlevel' => CONTEXT_USER), MUST_EXIST);
2131              context_helper::preload_from_record($user);
2132          }
2133  
2134          $iscurrentuser = ($user->id == $USER->id);
2135  
2136          $usercontext = context_user::instance($user->id);
2137  
2138          // Get the course set against the page, by default this will be the site
2139          $course = $this->page->course;
2140          $baseargs = array('id'=>$user->id);
2141          if ($course->id != $SITE->id && (!$iscurrentuser || $forceforcontext)) {
2142              $coursenode = $this->add_course($course, false, self::COURSE_CURRENT);
2143              $baseargs['course'] = $course->id;
2144              $coursecontext = context_course::instance($course->id);
2145              $issitecourse = false;
2146          } else {
2147              // Load all categories and get the context for the system
2148              $coursecontext = context_system::instance();
2149              $issitecourse = true;
2150          }
2151  
2152          // Create a node to add user information under.
2153          if ($iscurrentuser && !$forceforcontext) {
2154              // If it's the current user the information will go under the profile root node
2155              $usernode = $this->rootnodes['myprofile'];
2156              $course = get_site();
2157              $coursecontext = context_course::instance($course->id);
2158              $issitecourse = true;
2159          } else {
2160              if (!$issitecourse) {
2161                  // Not the current user so add it to the participants node for the current course
2162                  $usersnode = $coursenode->get('participants', navigation_node::TYPE_CONTAINER);
2163                  $userviewurl = new moodle_url('/user/view.php', $baseargs);
2164              } else {
2165                  // This is the site so add a users node to the root branch
2166                  $usersnode = $this->rootnodes['users'];
2167                  if (has_capability('moodle/course:viewparticipants', $coursecontext)) {
2168                      $usersnode->action = new moodle_url('/user/index.php', array('id'=>$course->id));
2169                  }
2170                  $userviewurl = new moodle_url('/user/profile.php', $baseargs);
2171              }
2172              if (!$usersnode) {
2173                  // We should NEVER get here, if the course hasn't been populated
2174                  // with a participants node then the navigaiton either wasn't generated
2175                  // for it (you are missing a require_login or set_context call) or
2176                  // you don't have access.... in the interests of no leaking informatin
2177                  // we simply quit...
2178                  return false;
2179              }
2180              // Add a branch for the current user
2181              $canseefullname = has_capability('moodle/site:viewfullnames', $coursecontext);
2182              $usernode = $usersnode->add(fullname($user, $canseefullname), $userviewurl, self::TYPE_USER, null, $user->id);
2183  
2184              if ($this->page->context->contextlevel == CONTEXT_USER && $user->id == $this->page->context->instanceid) {
2185                  $usernode->make_active();
2186              }
2187          }
2188  
2189          // If the user is the current user or has permission to view the details of the requested
2190          // user than add a view profile link.
2191          if ($iscurrentuser || has_capability('moodle/user:viewdetails', $coursecontext) || has_capability('moodle/user:viewdetails', $usercontext)) {
2192              if ($issitecourse || ($iscurrentuser && !$forceforcontext)) {
2193                  $usernode->add(get_string('viewprofile'), new moodle_url('/user/profile.php',$baseargs));
2194              } else {
2195                  $usernode->add(get_string('viewprofile'), new moodle_url('/user/view.php',$baseargs));
2196              }
2197          }
2198  
2199          if (!empty($CFG->navadduserpostslinks)) {
2200              // Add nodes for forum posts and discussions if the user can view either or both
2201              // There are no capability checks here as the content of the page is based
2202              // purely on the forums the current user has access too.
2203              $forumtab = $usernode->add(get_string('forumposts', 'forum'));
2204              $forumtab->add(get_string('posts', 'forum'), new moodle_url('/mod/forum/user.php', $baseargs));
2205              $forumtab->add(get_string('discussions', 'forum'), new moodle_url('/mod/forum/user.php', array_merge($baseargs, array('mode'=>'discussions'))));
2206          }
2207  
2208          // Add blog nodes
2209          if (!empty($CFG->enableblogs)) {
2210              if (!$this->cache->cached('userblogoptions'.$user->id)) {
2211                  require_once($CFG->dirroot.'/blog/lib.php');
2212                  // Get all options for the user
2213                  $options = blog_get_options_for_user($user);
2214                  $this->cache->set('userblogoptions'.$user->id, $options);
2215              } else {
2216                  $options = $this->cache->{'userblogoptions'.$user->id};
2217              }
2218  
2219              if (count($options) > 0) {
2220                  $blogs = $usernode->add(get_string('blogs', 'blog'), null, navigation_node::TYPE_CONTAINER);
2221                  foreach ($options as $type => $option) {
2222                      if ($type == "rss") {
2223                          $blogs->add($option['string'], $option['link'], settings_navigation::TYPE_SETTING, null, null, new pix_icon('i/rss', ''));
2224                      } else {
2225                          $blogs->add($option['string'], $option['link']);
2226                      }
2227                  }
2228              }
2229          }
2230  
2231          // Add the messages link.
2232          // It is context based so can appear in "My profile" and in course participants information.
2233          if (!empty($CFG->messaging)) {
2234              $messageargs = array('user1' => $USER->id);
2235              if ($USER->id != $user->id) {
2236                  $messageargs['user2'] = $user->id;
2237              }
2238              if ($course->id != $SITE->id) {
2239                  $messageargs['viewing'] = MESSAGE_VIEW_COURSE. $course->id;
2240              }
2241              $url = new moodle_url('/message/index.php',$messageargs);
2242              $usernode->add(get_string('messages', 'message'), $url, self::TYPE_SETTING, null, 'messages');
2243          }
2244  
2245          // Add the "My private files" link.
2246          // This link doesn't have a unique display for course context so only display it under "My profile".
2247          if ($issitecourse && $iscurrentuser && has_capability('moodle/user:manageownfiles', $usercontext)) {
2248              $url = new moodle_url('/user/files.php');
2249              $usernode->add(get_string('myfiles'), $url, self::TYPE_SETTING);
2250          }
2251  
2252          if (!empty($CFG->enablebadges) && $iscurrentuser &&
2253                  has_capability('moodle/badges:manageownbadges', $usercontext)) {
2254              $url = new moodle_url('/badges/mybadges.php');
2255              $usernode->add(get_string('mybadges', 'badges'), $url, self::TYPE_SETTING);
2256          }
2257  
2258          // Add a node to view the users notes if permitted
2259          if (!empty($CFG->enablenotes) && has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $coursecontext)) {
2260              $url = new moodle_url('/notes/index.php',array('user'=>$user->id));
2261              if ($coursecontext->instanceid != SITEID) {
2262                  $url->param('course', $coursecontext->instanceid);
2263              }
2264              $usernode->add(get_string('notes', 'notes'), $url);
2265          }
2266  
2267          // If the user is the current user add the repositories for the current user
2268          $hiddenfields = array_flip(explode(',', $CFG->hiddenuserfields));
2269          if ($iscurrentuser) {
2270              if (!$this->cache->cached('contexthasrepos'.$usercontext->id)) {
2271                  require_once($CFG->dirroot . '/repository/lib.php');
2272                  $editabletypes = repository::get_editable_types($usercontext);
2273                  $haseditabletypes = !empty($editabletypes);
2274                  unset($editabletypes);
2275                  $this->cache->set('contexthasrepos'.$usercontext->id, $haseditabletypes);
2276              } else {
2277                  $haseditabletypes = $this->cache->{'contexthasrepos'.$usercontext->id};
2278              }
2279              if ($haseditabletypes) {
2280                  $usernode->add(get_string('repositories', 'repository'), new moodle_url('/repository/manage_instances.php', array('contextid' => $usercontext->id)));
2281              }
2282          } else if ($course->id == $SITE->id && has_capability('moodle/user:viewdetails', $usercontext) && (!in_array('mycourses', $hiddenfields) || has_capability('moodle/user:viewhiddendetails', $coursecontext))) {
2283  
2284              // Add view grade report is permitted
2285              $reports = core_component::get_plugin_list('gradereport');
2286              arsort($reports); // user is last, we want to test it first
2287  
2288              $userscourses = enrol_get_users_courses($user->id);
2289              $userscoursesnode = $usernode->add(get_string('courses'));
2290  
2291              $count = 0;
2292              foreach ($userscourses as $usercourse) {
2293                  if ($count === (int)$CFG->navcourselimit) {
2294                      $url = new moodle_url('/user/profile.php', array('id' => $user->id, 'showallcourses' => 1));
2295                      $userscoursesnode->add(get_string('showallcourses'), $url);
2296                      break;
2297                  }
2298                  $count++;
2299                  $usercoursecontext = context_course::instance($usercourse->id);
2300                  $usercourseshortname = format_string($usercourse->shortname, true, array('context' => $usercoursecontext));
2301                  $usercoursenode = $userscoursesnode->add($usercourseshortname, new moodle_url('/user/view.php', array('id'=>$user->id, 'course'=>$usercourse->id)), self::TYPE_CONTAINER);
2302  
2303                  $gradeavailable = has_capability('moodle/grade:viewall', $usercoursecontext);
2304                  if (!$gradeavailable && !empty($usercourse->showgrades) && is_array($reports) && !empty($reports)) {
2305                      foreach ($reports as $plugin => $plugindir) {
2306                          if (has_capability('gradereport/'.$plugin.':view', $usercoursecontext)) {
2307                              //stop when the first visible plugin is found
2308                              $gradeavailable = true;
2309                              break;
2310                          }
2311                      }
2312                  }
2313  
2314                  if ($gradeavailable) {
2315                      $url = new moodle_url('/grade/report/index.php', array('id'=>$usercourse->id));
2316                      $usercoursenode->add(get_string('grades'), $url, self::TYPE_SETTING, null, null, new pix_icon('i/grades', ''));
2317                  }
2318  
2319                  // Add a node to view the users notes if permitted
2320                  if (!empty($CFG->enablenotes) && has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $usercoursecontext)) {
2321                      $url = new moodle_url('/notes/index.php',array('user'=>$user->id, 'course'=>$usercourse->id));
2322                      $usercoursenode->add(get_string('notes', 'notes'), $url, self::TYPE_SETTING);
2323                  }
2324  
2325                  if (can_access_course($usercourse, $user->id, '', true)) {
2326                      $usercoursenode->add(get_string('entercourse'), new moodle_url('/course/view.php', array('id'=>$usercourse->id)), self::TYPE_SETTING, null, null, new pix_icon('i/course', ''));
2327                  }
2328  
2329                  $reporttab = $usercoursenode->add(get_string('activityreports'));
2330  
2331                  $reports = get_plugin_list_with_function('report', 'extend_navigation_user', 'lib.php');
2332                  foreach ($reports as $reportfunction) {
2333                      $reportfunction($reporttab, $user, $usercourse);
2334                  }
2335  
2336                  $reporttab->trim_if_empty();
2337              }
2338          }
2339          return true;
2340      }
2341  
2342      /**
2343       * This method simply checks to see if a given module can extend the navigation.
2344       *
2345       * @todo (MDL-25290) A shared caching solution should be used to save details on what extends navigation.
2346       *
2347       * @param string $modname
2348       * @return bool
2349       */
2350      public static function module_extends_navigation($modname) {
2351          global $CFG;
2352          static $extendingmodules = array();
2353          if (!array_key_exists($modname, $extendingmodules)) {
2354              $extendingmodules[$modname] = false;
2355              $file = $CFG->dirroot.'/mod/'.$modname.'/lib.php';
2356              if (file_exists($file)) {
2357                  $function = $modname.'_extend_navigation';
2358                  require_once($file);
2359                  $extendingmodules[$modname] = (function_exists($function));
2360              }
2361          }
2362          return $extendingmodules[$modname];
2363      }
2364      /**
2365       * Extends the navigation for the given user.
2366       *
2367       * @param stdClass $user A user from the database
2368       */
2369      public function extend_for_user($user) {
2370          $this->extendforuser[] = $user;
2371      }
2372  
2373      /**
2374       * Returns all of the users the navigation is being extended for
2375       *
2376       * @return array An array of extending users.
2377       */
2378      public function get_extending_users() {
2379          return $this->extendforuser;
2380      }
2381      /**
2382       * Adds the given course to the navigation structure.
2383       *
2384       * @param stdClass $course
2385       * @param bool $forcegeneric
2386       * @param bool $ismycourse
2387       * @return navigation_node
2388       */
2389      public function add_course(stdClass $course, $forcegeneric = false, $coursetype = self::COURSE_OTHER) {
2390          global $CFG, $SITE;
2391  
2392          // We found the course... we can return it now :)
2393          if (!$forcegeneric && array_key_exists($course->id, $this->addedcourses)) {
2394              return $this->addedcourses[$course->id];
2395          }
2396  
2397          $coursecontext = context_course::instance($course->id);
2398  
2399          if ($course->id != $SITE->id && !$course->visible) {
2400              if (is_role_switched($course->id)) {
2401                  // user has to be able to access course in order to switch, let's skip the visibility test here
2402              } else if (!has_capability('moodle/course:viewhiddencourses', $coursecontext)) {
2403                  return false;
2404              }
2405          }
2406  
2407          $issite = ($course->id == $SITE->id);
2408          $shortname = format_string($course->shortname, true, array('context' => $coursecontext));
2409          $fullname = format_string($course->fullname, true, array('context' => $coursecontext));
2410          // This is the name that will be shown for the course.
2411          $coursename = empty($CFG->navshowfullcoursenames) ? $shortname : $fullname;
2412  
2413          // Can the user expand the course to see its content.
2414          $canexpandcourse = true;
2415          if ($issite) {
2416              $parent = $this;
2417              $url = null;
2418              if (empty($CFG->usesitenameforsitepages)) {
2419                  $coursename = get_string('sitepages');
2420              }
2421          } else if ($coursetype == self::COURSE_CURRENT) {
2422              $parent = $this->rootnodes['currentcourse'];
2423              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2424              $canexpandcourse = $this->can_expand_course($course);
2425          } else if ($coursetype == self::COURSE_MY && !$forcegeneric) {
2426              if (!empty($CFG->navshowmycoursecategories) && ($parent = $this->rootnodes['mycourses']->find($course->category, self::TYPE_MY_CATEGORY))) {
2427                  // Nothing to do here the above statement set $parent to the category within mycourses.
2428              } else {
2429                  $parent = $this->rootnodes['mycourses'];
2430              }
2431              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2432          } else {
2433              $parent = $this->rootnodes['courses'];
2434              $url = new moodle_url('/course/view.php', array('id'=>$course->id));
2435              // They can only expand the course if they can access it.
2436              $canexpandcourse = $this->can_expand_course($course);
2437              if (!empty($course->category) && $this->show_categories($coursetype == self::COURSE_MY)) {
2438                  if (!$this->is_category_fully_loaded($course->category)) {
2439                      // We need to load the category structure for this course
2440                      $this->load_all_categories($course->category, false);
2441                  }
2442                  if (array_key_exists($course->category, $this->addedcategories)) {
2443                      $parent = $this->addedcategories[$course->category];
2444                      // This could lead to the course being created so we should check whether it is the case again
2445                      if (!$forcegeneric && array_key_exists($course->id, $this->addedcourses)) {
2446                          return $this->addedcourses[$course->id];
2447                      }
2448                  }
2449              }
2450          }
2451  
2452          $coursenode = $parent->add($coursename, $url, self::TYPE_COURSE, $shortname, $course->id);
2453          $coursenode->hidden = (!$course->visible);
2454          // We need to decode &amp;'s here as they will have been added by format_string above and attributes will be encoded again
2455          // later.
2456          $coursenode->title(str_replace('&amp;', '&', $fullname));
2457          if ($canexpandcourse) {
2458              // This course can be expanded by the user, make it a branch to make the system aware that its expandable by ajax.
2459              $coursenode->nodetype = self::NODETYPE_BRANCH;
2460              $coursenode->isexpandable = true;
2461          } else {
2462              $coursenode->nodetype = self::NODETYPE_LEAF;
2463              $coursenode->isexpandable = false;
2464          }
2465          if (!$forcegeneric) {
2466              $this->addedcourses[$course->id] = $coursenode;
2467          }
2468  
2469          return $coursenode;
2470      }
2471  
2472      /**
2473       * Returns a cache instance to use for the expand course cache.
2474       * @return cache_session
2475       */
2476      protected function get_expand_course_cache() {
2477          if ($this->cacheexpandcourse === null) {
2478              $this->cacheexpandcourse = cache::make('core', 'navigation_expandcourse');
2479          }
2480          return $this->cacheexpandcourse;
2481      }
2482  
2483      /**
2484       * Checks if a user can expand a course in the navigation.
2485       *
2486       * We use a cache here because in order to be accurate we need to call can_access_course which is a costly function.
2487       * Because this functionality is basic + non-essential and because we lack good event triggering this cache
2488       * permits stale data.
2489       * In the situation the user is granted access to a course after we've initialised this session cache the cache
2490       * will be stale.
2491       * It is brought up to date in only one of two ways.
2492       *   1. The user logs out and in again.
2493       *   2. The user browses to the course they've just being given access to.
2494       *
2495       * Really all this controls is whether the node is shown as expandable or not. It is uber un-important.
2496       *
2497       * @param stdClass $course
2498       * @return bool
2499       */
2500      protected function can_expand_course($course) {
2501          $cache = $this->get_expand_course_cache();
2502          $canexpand = $cache->get($course->id);
2503          if ($canexpand === false) {
2504              $canexpand = isloggedin() && can_access_course($course, null, '', true);
2505              $canexpand = (int)$canexpand;
2506              $cache->set($course->id, $canexpand);
2507          }
2508          return ($canexpand === 1);
2509      }
2510  
2511      /**
2512       * Returns true if the category has already been loaded as have any child categories
2513       *
2514       * @param int $categoryid
2515       * @return bool
2516       */
2517      protected function is_category_fully_loaded($categoryid) {
2518          return (array_key_exists($categoryid, $this->addedcategories) && ($this->allcategoriesloaded || $this->addedcategories[$categoryid]->children->count() > 0));
2519      }
2520  
2521      /**
2522       * Adds essential course nodes to the navigation for the given course.
2523       *
2524       * This method adds nodes such as reports, blogs and participants
2525       *
2526       * @param navigation_node $coursenode
2527       * @param stdClass $course
2528       * @return bool returns true on successful addition of a node.
2529       */
2530      public function add_course_essentials($coursenode, stdClass $course) {
2531          global $CFG, $SITE;
2532  
2533          if ($course->id == $SITE->id) {
2534              return $this->add_front_page_course_essentials($coursenode, $course);
2535          }
2536  
2537          if ($coursenode == false || !($coursenode instanceof navigation_node) || $coursenode->get('participants', navigation_node::TYPE_CONTAINER)) {
2538              return true;
2539          }
2540  
2541          //Participants
2542          if (has_capability('moodle/course:viewparticipants', $this->page->context)) {
2543              $participants = $coursenode->add(get_string('participants'), new moodle_url('/user/index.php?id='.$course->id), self::TYPE_CONTAINER, get_string('participants'), 'participants');
2544              if (!empty($CFG->enableblogs)) {
2545                  if (($CFG->bloglevel == BLOG_GLOBAL_LEVEL or ($CFG->bloglevel == BLOG_SITE_LEVEL and (isloggedin() and !isguestuser())))
2546                     and has_capability('moodle/blog:view', context_system::instance())) {
2547                      $blogsurls = new moodle_url('/blog/index.php');
2548                      if ($course->id == $SITE->id) {
2549                          $blogsurls->param('courseid', 0);
2550                      } else if ($currentgroup = groups_get_course_group($course, true)) {
2551                          $blogsurls->param('groupid', $currentgroup);
2552                      } else {
2553                          $blogsurls->param('courseid', $course->id);
2554                      }
2555                      $participants->add(get_string('blogscourse','blog'), $blogsurls->out());
2556                  }
2557              }
2558              if (!empty($CFG->enablenotes) && (has_capability('moodle/notes:manage', $this->page->context) || has_capability('moodle/notes:view', $this->page->context))) {
2559                  $participants->add(get_string('notes','notes'), new moodle_url('/notes/index.php', array('filtertype'=>'course', 'filterselect'=>$course->id)));
2560              }
2561          } else if (count($this->extendforuser) > 0 || $this->page->course->id == $course->id) {
2562              $participants = $coursenode->add(get_string('participants'), null, self::TYPE_CONTAINER, get_string('participants'), 'participants');
2563          }
2564  
2565          // Badges.
2566          if (!empty($CFG->enablebadges) && !empty($CFG->badges_allowcoursebadges) &&
2567              has_capability('moodle/badges:viewbadges', $this->page->context)) {
2568              $url = new moodle_url('/badges/view.php', array('type' => 2, 'id' => $course->id));
2569  
2570              $coursenode->add(get_string('coursebadges', 'badges'), null,
2571                      navigation_node::TYPE_CONTAINER, null, 'coursebadges');
2572              $coursenode->get('coursebadges')->add(get_string('badgesview', 'badges'), $url,
2573                      navigation_node::TYPE_SETTING, null, 'badgesview',
2574                      new pix_icon('i/badge', get_string('badgesview', 'badges')));
2575          }
2576  
2577          return true;
2578      }
2579      /**
2580       * This generates the structure of the course that won't be generated when
2581       * the modules and sections are added.
2582       *
2583       * Things such as the reports branch, the participants branch, blogs... get
2584       * added to the course node by this method.
2585       *
2586       * @param navigation_node $coursenode
2587       * @param stdClass $course
2588       * @return bool True for successfull generation
2589       */
2590      public function add_front_page_course_essentials(navigation_node $coursenode, stdClass $course) {
2591          global $CFG;
2592  
2593          if ($coursenode == false || $coursenode->get('frontpageloaded', navigation_node::TYPE_CUSTOM)) {
2594              return true;
2595          }
2596  
2597          $sitecontext = context_system::instance();
2598  
2599          // Hidden node that we use to determine if the front page navigation is loaded.
2600          // This required as there are not other guaranteed nodes that may be loaded.
2601          $coursenode->add('frontpageloaded', null, self::TYPE_CUSTOM, null, 'frontpageloaded')->display = false;
2602  
2603          // Participants.
2604          // If this is the site course, they need to have moodle/site:viewparticipants at the site level.
2605          // If no, then they need to have moodle/course:viewparticipants at the course level.
2606          if ((($course->id == SITEID) && has_capability('moodle/site:viewparticipants', $sitecontext)) ||
2607                  has_capability('moodle/course:viewparticipants', context_course::instance($course->id))) {
2608              $coursenode->add(get_string('participants'), new moodle_url('/user/index.php?id='.$course->id), self::TYPE_CUSTOM, get_string('participants'), 'participants');
2609          }
2610  
2611          $filterselect = 0;
2612  
2613          // Blogs.
2614          if (!empty($CFG->enableblogs)
2615            and ($CFG->bloglevel == BLOG_GLOBAL_LEVEL or ($CFG->bloglevel == BLOG_SITE_LEVEL and (isloggedin() and !isguestuser())))
2616            and has_capability('moodle/blog:view', $sitecontext)) {
2617              $blogsurls = new moodle_url('/blog/index.php', array('courseid' => $filterselect));
2618              $coursenode->add(get_string('blogssite','blog'), $blogsurls->out());
2619          }
2620  
2621          // Badges.
2622          if (!empty($CFG->enablebadges) && has_capability('moodle/badges:viewbadges', $sitecontext)) {
2623              $url = new moodle_url($CFG->wwwroot . '/badges/view.php', array('type' => 1));
2624              $coursenode->add(get_string('sitebadges', 'badges'), $url, navigation_node::TYPE_CUSTOM);
2625          }
2626  
2627          // Notes.
2628          if (!empty($CFG->enablenotes) && has_any_capability(array('moodle/notes:manage', 'moodle/notes:view'), $sitecontext)) {
2629              $coursenode->add(get_string('notes','notes'), new moodle_url('/notes/index.php', array('filtertype'=>'course', 'filterselect'=>$filterselect)));
2630          }
2631  
2632          // Tags
2633          if (!empty($CFG->usetags) && isloggedin()) {
2634              $coursenode->add(get_string('tags', 'tag'), new moodle_url('/tag/search.php'));
2635          }
2636  
2637          if (isloggedin()) {
2638              // Calendar
2639              $calendarurl = new moodle_url('/calendar/view.php', array('view' => 'month'));
2640              $coursenode->add(get_string('calendar', 'calendar'), $calendarurl, self::TYPE_CUSTOM, null, 'calendar');
2641          }
2642  
2643          return true;
2644      }
2645  
2646      /**
2647       * Clears the navigation cache
2648       */
2649      public function clear_cache() {
2650          $this->cache->clear();
2651      }
2652  
2653      /**
2654       * Sets an expansion limit for the navigation
2655       *
2656       * The expansion limit is used to prevent the display of content that has a type
2657       * greater than the provided $type.
2658       *
2659       * Can be used to ensure things such as activities or activity content don't get
2660       * shown on the navigation.
2661       * They are still generated in order to ensure the navbar still makes sense.
2662       *
2663       * @param int $type One of navigation_node::TYPE_*
2664       * @return bool true when complete.
2665       */
2666      public function set_expansion_limit($type) {
2667          global $SITE;
2668          $nodes = $this->find_all_of_type($type);
2669  
2670          // We only want to hide specific types of nodes.
2671          // Only nodes that represent "structure" in the navigation tree should be hidden.
2672          // If we hide all nodes then we risk hiding vital information.
2673          $typestohide = array(
2674              self::TYPE_CATEGORY,
2675              self::TYPE_COURSE,
2676              self::TYPE_SECTION,
2677              self::TYPE_ACTIVITY
2678          );
2679  
2680          foreach ($nodes as $node) {
2681              // We need to generate the full site node
2682              if ($type == self::TYPE_COURSE && $node->key == $SITE->id) {
2683                  continue;
2684              }
2685              foreach ($node->children as $child) {
2686                  $child->hide($typestohide);
2687              }
2688          }
2689          return true;
2690      }
2691      /**
2692       * Attempts to get the navigation with the given key from this nodes children.
2693       *
2694       * This function only looks at this nodes children, it does NOT look recursivily.
2695       * If the node can't be found then false is returned.
2696       *
2697       * If you need to search recursivily then use the {@link global_navigation::find()} method.
2698       *
2699       * Note: If you are trying to set the active node {@link navigation_node::override_active_url()}
2700       * may be of more use to you.
2701       *
2702       * @param string|int $key The key of the node you wish to receive.
2703       * @param int $type One of navigation_node::TYPE_*
2704       * @return navigation_node|false
2705       */
2706      public function get($key, $type = null) {
2707          if (!$this->initialised) {
2708              $this->initialise();
2709          }
2710          return parent::get($key, $type);
2711      }
2712  
2713      /**
2714       * Searches this nodes children and their children to find a navigation node
2715       * with the matching key and type.
2716       *
2717       * This method is recursive and searches children so until either a node is
2718       * found or there are no more nodes to search.
2719       *
2720       * If you know that the node being searched for is a child of this node
2721       * then use the {@link global_navigation::get()} method instead.
2722       *
2723       * Note: If you are trying to set the active node {@link navigation_node::override_active_url()}
2724       * may be of more use to you.
2725       *
2726       * @param string|int $key The key of the node you wish to receive.
2727       * @param int $type One of navigation_node::TYPE_*
2728       * @return navigation_node|false
2729       */
2730      public function find($key, $type) {
2731          if (!$this->initialised) {
2732              $this->initialise();
2733          }
2734          if ($type == self::TYPE_ROOTNODE && array_key_exists($key, $this->rootnodes)) {
2735              return $this->rootnodes[$key];
2736          }
2737          return parent::find($key, $type);
2738      }
2739  
2740      /**
2741       * They've expanded the 'my courses' branch.
2742       */
2743      protected function load_courses_enrolled() {
2744          global $CFG, $DB;
2745          $sortorder = 'visible DESC';
2746          // Prevent undefined $CFG->navsortmycoursessort errors.
2747          if (empty($CFG->navsortmycoursessort)) {
2748              $CFG->navsortmycoursessort = 'sortorder';
2749          }
2750          // Append the chosen sortorder.
2751          $sortorder = $sortorder . ',' . $CFG->navsortmycoursessort . ' ASC';
2752          $courses = enrol_get_my_courses(null, $sortorder);
2753          if (count($courses) && $this->show_my_categories()) {
2754              // OK Actually we are loading categories. We only want to load categories that have a parent of 0.
2755              // In order to make sure we load everything required we must first find the categories that are not
2756              // base categories and work out the bottom category in thier path.
2757              $categoryids = array();
2758              foreach ($courses as $course) {
2759                  $categoryids[] = $course->category;
2760              }
2761              $categoryids = array_unique($categoryids);
2762              list($sql, $params) = $DB->get_in_or_equal($categoryids);
2763              $categories = $DB->get_recordset_select('course_categories', 'id '.$sql.' AND parent <> 0', $params, 'sortorder, id', 'id, path');
2764              foreach ($categories as $category) {
2765                  $bits = explode('/', trim($category->path,'/'));
2766                  $categoryids[] = array_shift($bits);
2767              }
2768              $categoryids = array_unique($categoryids);
2769              $categories->close();
2770  
2771              // Now we load the base categories.
2772              list($sql, $params) = $DB->get_in_or_equal($categoryids);
2773              $categories = $DB->get_recordset_select('course_categories', 'id '.$sql.' AND parent = 0', $params, 'sortorder, id');
2774              foreach ($categories as $category) {
2775                  $this->add_category($category, $this->rootnodes['mycourses'], self::TYPE_MY_CATEGORY);
2776              }
2777              $categories->close();
2778          } else {
2779              foreach ($courses as $course) {
2780                  $this->add_course($course, false, self::COURSE_MY);
2781              }
2782          }
2783      }
2784  }
2785  
2786  /**
2787   * The global navigation class used especially for AJAX requests.
2788   *
2789   * The primary methods that are used in the global navigation class have been overriden
2790   * to ensure that only the relevant branch is generated at the root of the tree.
2791   * This can be done because AJAX is only used when the backwards structure for the
2792   * requested branch exists.
2793   * This has been done only because it shortens the amounts of information that is generated
2794   * which of course will speed up the response time.. because no one likes laggy AJAX.
2795   *
2796   * @package   core
2797   * @category  navigation
2798   * @copyright 2009 Sam Hemelryk
2799   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2800   */
2801  class global_navigation_for_ajax extends global_navigation {
2802  
2803      /** @var int used for determining what type of navigation_node::TYPE_* is being used */
2804      protected $branchtype;
2805  
2806      /** @var int the instance id */
2807      protected $instanceid;
2808  
2809      /** @var array Holds an array of expandable nodes */
2810      protected $expandable = array();
2811  
2812      /**
2813       * Constructs the navigation for use in an AJAX request
2814       *
2815       * @param moodle_page $page moodle_page object
2816       * @param int $branchtype
2817       * @param int $id
2818       */
2819      public function __construct($page, $branchtype, $id) {
2820          $this->page = $page;
2821          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
2822          $this->children = new navigation_node_collection();
2823          $this->branchtype = $branchtype;
2824          $this->instanceid = $id;
2825          $this->initialise();
2826      }
2827      /**
2828       * Initialise the navigation given the type and id for the branch to expand.
2829       *
2830       * @return array An array of the expandable nodes
2831       */
2832      public function initialise() {
2833          global $DB, $SITE;
2834  
2835          if ($this->initialised || during_initial_install()) {
2836              return $this->expandable;
2837          }
2838          $this->initialised = true;
2839  
2840          $this->rootnodes = array();
2841          $this->rootnodes['site']    = $this->add_course($SITE);
2842          $this->rootnodes['mycourses'] = $this->add(get_string('mycourses'), new moodle_url('/my'), self::TYPE_ROOTNODE, null, 'mycourses');
2843          $this->rootnodes['courses'] = $this->add(get_string('courses'), null, self::TYPE_ROOTNODE, null, 'courses');
2844          // The courses branch is always displayed, and is always expandable (although may be empty).
2845          // This mimicks what is done during {@link global_navigation::initialise()}.
2846          $this->rootnodes['courses']->isexpandable = true;
2847  
2848          // Branchtype will be one of navigation_node::TYPE_*
2849          switch ($this->branchtype) {
2850              case 0:
2851                  if ($this->instanceid === 'mycourses') {
2852                      $this->load_courses_enrolled();
2853                  } else if ($this->instanceid === 'courses') {
2854                      $this->load_courses_other();
2855                  }
2856                  break;
2857              case self::TYPE_CATEGORY :
2858                  $this->load_category($this->instanceid);
2859                  break;
2860              case self::TYPE_MY_CATEGORY :
2861                  $this->load_category($this->instanceid, self::TYPE_MY_CATEGORY);
2862                  break;
2863              case self::TYPE_COURSE :
2864                  $course = $DB->get_record('course', array('id' => $this->instanceid), '*', MUST_EXIST);
2865                  if (!can_access_course($course, null, '', true)) {
2866                      // Thats OK all courses are expandable by default. We don't need to actually expand it we can just
2867                      // add the course node and break. This leads to an empty node.
2868                      $this->add_course($course);
2869                      break;
2870                  }
2871                  require_course_login($course, true, null, false, true);
2872                  $this->page->set_context(context_course::instance($course->id));
2873                  $coursenode = $this->add_course($course);
2874                  $this->add_course_essentials($coursenode, $course);
2875                  $this->load_course_sections($course, $coursenode);
2876                  break;
2877              case self::TYPE_SECTION :
2878                  $sql = 'SELECT c.*, cs.section AS sectionnumber
2879                          FROM {course} c
2880                          LEFT JOIN {course_sections} cs ON cs.course = c.id
2881                          WHERE cs.id = ?';
2882                  $course = $DB->get_record_sql($sql, array($this->instanceid), MUST_EXIST);
2883                  require_course_login($course, true, null, false, true);
2884                  $this->page->set_context(context_course::instance($course->id));
2885                  $coursenode = $this->add_course($course);
2886                  $this->add_course_essentials($coursenode, $course);
2887                  $this->load_course_sections($course, $coursenode, $course->sectionnumber);
2888                  break;
2889              case self::TYPE_ACTIVITY :
2890                  $sql = "SELECT c.*
2891                            FROM {course} c
2892                            JOIN {course_modules} cm ON cm.course = c.id
2893                           WHERE cm.id = :cmid";
2894                  $params = array('cmid' => $this->instanceid);
2895                  $course = $DB->get_record_sql($sql, $params, MUST_EXIST);
2896                  $modinfo = get_fast_modinfo($course);
2897                  $cm = $modinfo->get_cm($this->instanceid);
2898                  require_course_login($course, true, $cm, false, true);
2899                  $this->page->set_context(context_module::instance($cm->id));
2900                  $coursenode = $this->load_course($course);
2901                  $this->load_course_sections($course, $coursenode, null, $cm);
2902                  $activitynode = $coursenode->find($cm->id, self::TYPE_ACTIVITY);
2903                  if ($activitynode) {
2904                      $modulenode = $this->load_activity($cm, $course, $activitynode);
2905                  }
2906                  break;
2907              default:
2908                  throw new Exception('Unknown type');
2909                  return $this->expandable;
2910          }
2911  
2912          if ($this->page->context->contextlevel == CONTEXT_COURSE && $this->page->context->instanceid != $SITE->id) {
2913              $this->load_for_user(null, true);
2914          }
2915  
2916          $this->find_expandable($this->expandable);
2917          return $this->expandable;
2918      }
2919  
2920      /**
2921       * They've expanded the general 'courses' branch.
2922       */
2923      protected function load_courses_other() {
2924          $this->load_all_courses();
2925      }
2926  
2927      /**
2928       * Loads a single category into the AJAX navigation.
2929       *
2930       * This function is special in that it doesn't concern itself with the parent of
2931       * the requested category or its siblings.
2932       * This is because with the AJAX navigation we know exactly what is wanted and only need to
2933       * request that.
2934       *
2935       * @global moodle_database $DB
2936       * @param int $categoryid id of category to load in navigation.
2937       * @param int $nodetype type of node, if category is under MyHome then it's TYPE_MY_CATEGORY
2938       * @return void.
2939       */
2940      protected function load_category($categoryid, $nodetype = self::TYPE_CATEGORY) {
2941          global $CFG, $DB;
2942  
2943          $limit = 20;
2944          if (!empty($CFG->navcourselimit)) {
2945              $limit = (int)$CFG->navcourselimit;
2946          }
2947  
2948          $catcontextsql = context_helper::get_preload_record_columns_sql('ctx');
2949          $sql = "SELECT cc.*, $catcontextsql
2950                    FROM {course_categories} cc
2951                    JOIN {context} ctx ON cc.id = ctx.instanceid
2952                   WHERE ctx.contextlevel = ".CONTEXT_COURSECAT." AND
2953                         (cc.id = :categoryid1 OR cc.parent = :categoryid2)
2954                ORDER BY cc.depth ASC, cc.sortorder ASC, cc.id ASC";
2955          $params = array('categoryid1' => $categoryid, 'categoryid2' => $categoryid);
2956          $categories = $DB->get_recordset_sql($sql, $params, 0, $limit);
2957          $categorylist = array();
2958          $subcategories = array();
2959          $basecategory = null;
2960          foreach ($categories as $category) {
2961              $categorylist[] = $category->id;
2962              context_helper::preload_from_record($category);
2963              if ($category->id == $categoryid) {
2964                  $this->add_category($category, $this, $nodetype);
2965                  $basecategory = $this->addedcategories[$category->id];
2966              } else {
2967                  $subcategories[$category->id] = $category;
2968              }
2969          }
2970          $categories->close();
2971  
2972  
2973          // If category is shown in MyHome then only show enrolled courses and hide empty subcategories,
2974          // else show all courses.
2975          if ($nodetype === self::TYPE_MY_CATEGORY) {
2976              $courses = enrol_get_my_courses();
2977              $categoryids = array();
2978  
2979              // Only search for categories if basecategory was found.
2980              if (!is_null($basecategory)) {
2981                  // Get course parent category ids.
2982                  foreach ($courses as $course) {
2983                      $categoryids[] = $course->category;
2984                  }
2985  
2986                  // Get a unique list of category ids which a part of the path
2987                  // to user's courses.
2988                  $coursesubcategories = array();
2989                  $addedsubcategories = array();
2990  
2991                  list($sql, $params) = $DB->get_in_or_equal($categoryids);
2992                  $categories = $DB->get_recordset_select('course_categories', 'id '.$sql, $params, 'sortorder, id', 'id, path');
2993  
2994                  foreach ($categories as $category){
2995                      $coursesubcategories = array_merge($coursesubcategories, explode('/', trim($category->path, "/")));
2996                  }
2997                  $coursesubcategories = array_unique($coursesubcategories);
2998  
2999                  // Only add a subcategory if it is part of the path to user's course and
3000                  // wasn't already added.
3001                  foreach ($subcategories as $subid => $subcategory) {
3002                      if (in_array($subid, $coursesubcategories) &&
3003                              !in_array($subid, $addedsubcategories)) {
3004                              $this->add_category($subcategory, $basecategory, $nodetype);
3005                              $addedsubcategories[] = $subid;
3006                      }
3007                  }
3008              }
3009  
3010              foreach ($courses as $course) {
3011                  // Add course if it's in category.
3012                  if (in_array($course->category, $categorylist)) {
3013                      $this->add_course($course, true, self::COURSE_MY);
3014                  }
3015              }
3016          } else {
3017              if (!is_null($basecategory)) {
3018                  foreach ($subcategories as $key=>$category) {
3019                      $this->add_category($category, $basecategory, $nodetype);
3020                  }
3021              }
3022              $courses = $DB->get_recordset('course', array('category' => $categoryid), 'sortorder', '*' , 0, $limit);
3023              foreach ($courses as $course) {
3024                  $this->add_course($course);
3025              }
3026              $courses->close();
3027          }
3028      }
3029  
3030      /**
3031       * Returns an array of expandable nodes
3032       * @return array
3033       */
3034      public function get_expandable() {
3035          return $this->expandable;
3036      }
3037  }
3038  
3039  /**
3040   * Navbar class
3041   *
3042   * This class is used to manage the navbar, which is initialised from the navigation
3043   * object held by PAGE
3044   *
3045   * @package   core
3046   * @category  navigation
3047   * @copyright 2009 Sam Hemelryk
3048   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3049   */
3050  class navbar extends navigation_node {
3051      /** @var bool A switch for whether the navbar is initialised or not */
3052      protected $initialised = false;
3053      /** @var mixed keys used to reference the nodes on the navbar */
3054      protected $keys = array();
3055      /** @var null|string content of the navbar */
3056      protected $content = null;
3057      /** @var moodle_page object the moodle page that this navbar belongs to */
3058      protected $page;
3059      /** @var bool A switch for whether to ignore the active navigation information */
3060      protected $ignoreactive = false;
3061      /** @var bool A switch to let us know if we are in the middle of an install */
3062      protected $duringinstall = false;
3063      /** @var bool A switch for whether the navbar has items */
3064      protected $hasitems = false;
3065      /** @var array An array of navigation nodes for the navbar */
3066      protected $items;
3067      /** @var array An array of child node objects */
3068      public $children = array();
3069      /** @var bool A switch for whether we want to include the root node in the navbar */
3070      public $includesettingsbase = false;
3071      /** @var navigation_node[] $prependchildren */
3072      protected $prependchildren = array();
3073      /**
3074       * The almighty constructor
3075       *
3076       * @param moodle_page $page
3077       */
3078      public function __construct(moodle_page $page) {
3079          global $CFG;
3080          if (during_initial_install()) {
3081              $this->duringinstall = true;
3082              return false;
3083          }
3084          $this->page = $page;
3085          $this->text = get_string('home');
3086          $this->shorttext = get_string('home');
3087          $this->action = new moodle_url($CFG->wwwroot);
3088          $this->nodetype = self::NODETYPE_BRANCH;
3089          $this->type = self::TYPE_SYSTEM;
3090      }
3091  
3092      /**
3093       * Quick check to see if the navbar will have items in.
3094       *
3095       * @return bool Returns true if the navbar will have items, false otherwise
3096       */
3097      public function has_items() {
3098          if ($this->duringinstall) {
3099              return false;
3100          } else if ($this->hasitems !== false) {
3101              return true;
3102          }
3103          $this->page->navigation->initialise($this->page);
3104  
3105          $activenodefound = ($this->page->navigation->contains_active_node() ||
3106                              $this->page->settingsnav->contains_active_node());
3107  
3108          $outcome = (count($this->children) > 0 || count($this->prependchildren) || (!$this->ignoreactive && $activenodefound));
3109          $this->hasitems = $outcome;
3110          return $outcome;
3111      }
3112  
3113      /**
3114       * Turn on/off ignore active
3115       *
3116       * @param bool $setting
3117       */
3118      public function ignore_active($setting=true) {
3119          $this->ignoreactive = ($setting);
3120      }
3121  
3122      /**
3123       * Gets a navigation node
3124       *
3125       * @param string|int $key for referencing the navbar nodes
3126       * @param int $type navigation_node::TYPE_*
3127       * @return navigation_node|bool
3128       */
3129      public function get($key, $type = null) {
3130          foreach ($this->children as &$child) {
3131              if ($child->key === $key && ($type == null || $type == $child->type)) {
3132                  return $child;
3133              }
3134          }
3135          foreach ($this->prependchildren as &$child) {
3136              if ($child->key === $key && ($type == null || $type == $child->type)) {
3137                  return $child;
3138              }
3139          }
3140          return false;
3141      }
3142      /**
3143       * Returns an array of navigation_node's that make up the navbar.
3144       *
3145       * @return array
3146       */
3147      public function get_items() {
3148          global $CFG;
3149          $items = array();
3150          // Make sure that navigation is initialised
3151          if (!$this->has_items()) {
3152              return $items;
3153          }
3154          if ($this->items !== null) {
3155              return $this->items;
3156          }
3157  
3158          if (count($this->children) > 0) {
3159              // Add the custom children.
3160              $items = array_reverse($this->children);
3161          }
3162  
3163          $navigationactivenode = $this->page->navigation->find_active_node();
3164          $settingsactivenode = $this->page->settingsnav->find_active_node();
3165  
3166          // Check if navigation contains the active node
3167          if (!$this->ignoreactive) {
3168  
3169              if ($navigationactivenode && $settingsactivenode) {
3170                  // Parse a combined navigation tree
3171                  while ($settingsactivenode && $settingsactivenode->parent !== null) {
3172                      if (!$settingsactivenode->mainnavonly) {
3173                          $items[] = $settingsactivenode;
3174                      }
3175                      $settingsactivenode = $settingsactivenode->parent;
3176                  }
3177                  if (!$this->includesettingsbase) {
3178                      // Removes the first node from the settings (root node) from the list
3179                      array_pop($items);
3180                  }
3181                  while ($navigationactivenode && $navigationactivenode->parent !== null) {
3182                      if (!$navigationactivenode->mainnavonly) {
3183                          $items[] = $navigationactivenode;
3184                      }
3185                      if (!empty($CFG->navshowcategories) &&
3186                              $navigationactivenode->type === self::TYPE_COURSE &&
3187                              $navigationactivenode->parent->key === 'currentcourse') {
3188                          $items = array_merge($items, $this->get_course_categories());
3189                      }
3190                      $navigationactivenode = $navigationactivenode->parent;
3191                  }
3192              } else if ($navigationactivenode) {
3193                  // Parse the navigation tree to get the active node
3194                  while ($navigationactivenode && $navigationactivenode->parent !== null) {
3195                      if (!$navigationactivenode->mainnavonly) {
3196                          $items[] = $navigationactivenode;
3197                      }
3198                      if (!empty($CFG->navshowcategories) &&
3199                              $navigationactivenode->type === self::TYPE_COURSE &&
3200                              $navigationactivenode->parent->key === 'currentcourse') {
3201                          $items = array_merge($items, $this->get_course_categories());
3202                      }
3203                      $navigationactivenode = $navigationactivenode->parent;
3204                  }
3205              } else if ($settingsactivenode) {
3206                  // Parse the settings navigation to get the active node
3207                  while ($settingsactivenode && $settingsactivenode->parent !== null) {
3208                      if (!$settingsactivenode->mainnavonly) {
3209                          $items[] = $settingsactivenode;
3210                      }
3211                      $settingsactivenode = $settingsactivenode->parent;
3212                  }
3213              }
3214          }
3215  
3216          $items[] = new navigation_node(array(
3217              'text'=>$this->page->navigation->text,
3218              'shorttext'=>$this->page->navigation->shorttext,
3219              'key'=>$this->page->navigation->key,
3220              'action'=>$this->page->navigation->action
3221          ));
3222  
3223          if (count($this->prependchildren) > 0) {
3224              // Add the custom children
3225              $items = array_merge($items, array_reverse($this->prependchildren));
3226          }
3227  
3228          $this->items = array_reverse($items);
3229          return $this->items;
3230      }
3231  
3232      /**
3233       * Get the list of categories leading to this course.
3234       *
3235       * This function is used by {@link navbar::get_items()} to add back the "courses"
3236       * node and category chain leading to the current course.  Note that this is only ever
3237       * called for the current course, so we don't need to bother taking in any parameters.
3238       *
3239       * @return array
3240       */
3241      private function get_course_categories() {
3242          global $CFG;
3243  
3244          require_once($CFG->dirroot.'/course/lib.php');
3245          $categories = array();
3246          $cap = 'moodle/category:viewhiddencategories';
3247          foreach ($this->page->categories as $category) {
3248              if (!$category->visible && !has_capability($cap, get_category_or_system_context($category->parent))) {
3249                  continue;
3250              }
3251              $url = new moodle_url('/course/index.php', array('categoryid' => $category->id));
3252              $name = format_string($category->name, true, array('context' => context_coursecat::instance($category->id)));
3253              $categorynode = navigation_node::create($name, $url, self::TYPE_CATEGORY, null, $category->id);
3254              if (!$category->visible) {
3255                  $categorynode->hidden = true;
3256              }
3257              $categories[] = $categorynode;
3258          }
3259          if (is_enrolled(context_course::instance($this->page->course->id), null, '', true)) {
3260              $courses = $this->page->navigation->get('mycourses');
3261          } else {
3262              $courses = $this->page->navigation->get('courses');
3263          }
3264          if (!$courses) {
3265              // Courses node may not be present.
3266              $courses = navigation_node::create(
3267                  get_string('courses'),
3268                  new moodle_url('/course/index.php'),
3269                  self::TYPE_CONTAINER
3270              );
3271          }
3272          $categories[] = $courses;
3273          return $categories;
3274      }
3275  
3276      /**
3277       * Add a new navigation_node to the navbar, overrides parent::add
3278       *
3279       * This function overrides {@link navigation_node::add()} so that we can change
3280       * the way nodes get added to allow us to simply call add and have the node added to the
3281       * end of the navbar
3282       *
3283       * @param string $text
3284       * @param string|moodle_url|action_link $action An action to associate with this node.
3285       * @param int $type One of navigation_node::TYPE_*
3286       * @param string $shorttext
3287       * @param string|int $key A key to identify this node with. Key + type is unique to a parent.
3288       * @param pix_icon $icon An optional icon to use for this node.
3289       * @return navigation_node
3290       */
3291      public function add($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
3292          if ($this->content !== null) {
3293              debugging('Nav bar items must be printed before $OUTPUT->header() has been called', DEBUG_DEVELOPER);
3294          }
3295  
3296          // Properties array used when creating the new navigation node
3297          $itemarray = array(
3298              'text' => $text,
3299              'type' => $type
3300          );
3301          // Set the action if one was provided
3302          if ($action!==null) {
3303              $itemarray['action'] = $action;
3304          }
3305          // Set the shorttext if one was provided
3306          if ($shorttext!==null) {
3307              $itemarray['shorttext'] = $shorttext;
3308          }
3309          // Set the icon if one was provided
3310          if ($icon!==null) {
3311              $itemarray['icon'] = $icon;
3312          }
3313          // Default the key to the number of children if not provided
3314          if ($key === null) {
3315              $key = count($this->children);
3316          }
3317          // Set the key
3318          $itemarray['key'] = $key;
3319          // Set the parent to this node
3320          $itemarray['parent'] = $this;
3321          // Add the child using the navigation_node_collections add method
3322          $this->children[] = new navigation_node($itemarray);
3323          return $this;
3324      }
3325  
3326      /**
3327       * Prepends a new navigation_node to the start of the navbar
3328       *
3329       * @param string $text
3330       * @param string|moodle_url|action_link $action An action to associate with this node.
3331       * @param int $type One of navigation_node::TYPE_*
3332       * @param string $shorttext
3333       * @param string|int $key A key to identify this node with. Key + type is unique to a parent.
3334       * @param pix_icon $icon An optional icon to use for this node.
3335       * @return navigation_node
3336       */
3337      public function prepend($text, $action=null, $type=self::TYPE_CUSTOM, $shorttext=null, $key=null, pix_icon $icon=null) {
3338          if ($this->content !== null) {
3339              debugging('Nav bar items must be printed before $OUTPUT->header() has been called', DEBUG_DEVELOPER);
3340          }
3341          // Properties array used when creating the new navigation node.
3342          $itemarray = array(
3343              'text' => $text,
3344              'type' => $type
3345          );
3346          // Set the action if one was provided.
3347          if ($action!==null) {
3348              $itemarray['action'] = $action;
3349          }
3350          // Set the shorttext if one was provided.
3351          if ($shorttext!==null) {
3352              $itemarray['shorttext'] = $shorttext;
3353          }
3354          // Set the icon if one was provided.
3355          if ($icon!==null) {
3356              $itemarray['icon'] = $icon;
3357          }
3358          // Default the key to the number of children if not provided.
3359          if ($key === null) {
3360              $key = count($this->children);
3361          }
3362          // Set the key.
3363          $itemarray['key'] = $key;
3364          // Set the parent to this node.
3365          $itemarray['parent'] = $this;
3366          // Add the child node to the prepend list.
3367          $this->prependchildren[] = new navigation_node($itemarray);
3368          return $this;
3369      }
3370  }
3371  
3372  /**
3373   * Class used to manage the settings option for the current page
3374   *
3375   * This class is used to manage the settings options in a tree format (recursively)
3376   * and was created initially for use with the settings blocks.
3377   *
3378   * @package   core
3379   * @category  navigation
3380   * @copyright 2009 Sam Hemelryk
3381   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
3382   */
3383  class settings_navigation extends navigation_node {
3384      /** @var stdClass the current context */
3385      protected $context;
3386      /** @var moodle_page the moodle page that the navigation belongs to */
3387      protected $page;
3388      /** @var string contains administration section navigation_nodes */
3389      protected $adminsection;
3390      /** @var bool A switch to see if the navigation node is initialised */
3391      protected $initialised = false;
3392      /** @var array An array of users that the nodes can extend for. */
3393      protected $userstoextendfor = array();
3394      /** @var navigation_cache **/
3395      protected $cache;
3396  
3397      /**
3398       * Sets up the object with basic settings and preparse it for use
3399       *
3400       * @param moodle_page $page
3401       */
3402      public function __construct(moodle_page &$page) {
3403          if (during_initial_install()) {
3404              return false;
3405          }
3406          $this->page = $page;
3407          // Initialise the main navigation. It is most important that this is done
3408          // before we try anything
3409          $this->page->navigation->initialise();
3410          // Initialise the navigation cache
3411          $this->cache = new navigation_cache(NAVIGATION_CACHE_NAME);
3412          $this->children = new navigation_node_collection();
3413      }
3414      /**
3415       * Initialise the settings navigation based on the current context
3416       *
3417       * This function initialises the settings navigation tree for a given context
3418       * by calling supporting functions to generate major parts of the tree.
3419       *
3420       */
3421      public function initialise() {
3422          global $DB, $SESSION, $SITE;
3423  
3424          if (during_initial_install()) {
3425              return false;
3426          } else if ($this->initialised) {
3427              return true;
3428          }
3429          $this->id = 'settingsnav';
3430          $this->context = $this->page->context;
3431  
3432          $context = $this->context;
3433          if ($context->contextlevel == CONTEXT_BLOCK) {
3434              $this->load_block_settings();
3435              $context = $context->get_parent_context();
3436          }
3437          switch ($context->contextlevel) {
3438              case CONTEXT_SYSTEM:
3439                  if ($this->page->url->compare(new moodle_url('/admin/settings.php', array('section'=>'frontpagesettings')))) {
3440                      $this->load_front_page_settings(($context->id == $this->context->id));
3441                  }
3442                  break;
3443              case CONTEXT_COURSECAT:
3444                  $this->load_category_settings();
3445                  break;
3446              case CONTEXT_COURSE:
3447                  if ($this->page->course->id != $SITE->id) {
3448                      $this->load_course_settings(($context->id == $this->context->id));
3449                  } else {
3450                      $this->load_front_page_settings(($context->id == $this->context->id));
3451                  }
3452                  break;
3453              case CONTEXT_MODULE:
3454                  $this->load_module_settings();
3455                  $this->load_course_settings();
3456                  break;
3457              case CONTEXT_USER:
3458                  if ($this->page->course->id != $SITE->id) {
3459                      $this->load_course_settings();
3460                  }
3461                  break;
3462          }
3463  
3464          $usersettings = $this->load_user_settings($this->page->course->id);
3465  
3466          $adminsettings = false;
3467          if (isloggedin() && !isguestuser() && (!isset($SESSION->load_navigation_admin) || $SESSION->load_navigation_admin)) {
3468              $isadminpage = $this->is_admin_tree_needed();
3469  
3470              if (has_capability('moodle/site:config', context_system::instance())) {
3471                  // Make sure this works even if config capability changes on the fly
3472                  // and also make it fast for admin right after login.
3473                  $SESSION->load_navigation_admin = 1;
3474                  if ($isadminpage) {
3475                      $adminsettings = $this->load_administration_settings();
3476                  }
3477  
3478              } else if (!isset($SESSION->load_navigation_admin)) {
3479                  $adminsettings = $this->load_administration_settings();
3480                  $SESSION->load_navigation_admin = (int)($adminsettings->children->count() > 0);
3481  
3482              } else if ($SESSION->load_navigation_admin) {
3483                  if ($isadminpage) {
3484                      $adminsettings = $this->load_administration_settings();
3485                  }
3486              }
3487  
3488              // Print empty navigation node, if needed.
3489              if ($SESSION->load_navigation_admin && !$isadminpage) {
3490                  if ($adminsettings) {
3491                      // Do not print settings tree on pages that do not need it, this helps with performance.
3492                      $adminsettings->remove();
3493                      $adminsettings = false;
3494                  }
3495                  $siteadminnode = $this->add(get_string('administrationsite'), new moodle_url('/admin'), self::TYPE_SITE_ADMIN, null, 'siteadministration');
3496                  $siteadminnode->id = 'expandable_branch_'.$siteadminnode->type.'_'.clean_param($siteadminnode->key, PARAM_ALPHANUMEXT);
3497                  $this->page->requires->data_for_js('siteadminexpansion', $siteadminnode);
3498              }
3499          }
3500  
3501          if ($context->contextlevel == CONTEXT_SYSTEM && $adminsettings) {
3502              $adminsettings->force_open();
3503          } else if ($context->contextlevel == CONTEXT_USER && $usersettings) {
3504              $usersettings->force_open();
3505          }
3506  
3507          // Check if the user is currently logged in as another user
3508          if (\core\session\manager::is_loggedinas()) {
3509              // Get the actual user, we need this so we can display an informative return link
3510              $realuser = \core\session\manager::get_realuser();
3511              // Add the informative return to original user link
3512              $url = new moodle_url('/course/loginas.php',array('id'=>$this->page->course->id, 'return'=>1,'sesskey'=>sesskey()));
3513              $this->add(get_string('returntooriginaluser', 'moodle', fullname($realuser, true)), $url, self::TYPE_SETTING, null, null, new pix_icon('t/left', ''));
3514          }
3515  
3516          // At this point we give any local plugins the ability to extend/tinker with the navigation settings.
3517          $this->load_local_plugin_settings();
3518  
3519          foreach ($this->children as $key=>$node) {
3520              if ($node->nodetype != self::NODETYPE_BRANCH || $node->children->count()===0) {
3521                  // Site administration is shown as link.
3522                  if (!empty($SESSION->load_navigation_admin) && ($node->type === self::TYPE_SITE_ADMIN)) {
3523                      continue;
3524                  }
3525                  $node->remove();
3526              }
3527          }
3528          $this->initialised = true;
3529      }
3530      /**
3531       * Override the parent function so that we can add preceeding hr's and set a
3532       * root node class against all first level element
3533       *
3534       * It does this by first calling the parent's add method {@link navigation_node::add()}
3535       * and then proceeds to use the key to set class and hr
3536       *
3537       * @param string $text text to be used for the link.
3538       * @param string|moodle_url $url url for the new node
3539       * @param int $type the type of node navigation_node::TYPE_*
3540       * @param string $shorttext
3541       * @param string|int $key a key to access the node by.
3542       * @param pix_icon $icon An icon that appears next to the node.
3543       * @return navigation_node with the new node added to it.
3544       */
3545      public function add($text, $url=null, $type=null, $shorttext=null, $key=null, pix_icon $icon=null) {
3546          $node = parent::add($text, $url, $type, $shorttext, $key, $icon);
3547          $node->add_class('root_node');
3548          return $node;
3549      }
3550  
3551      /**
3552       * This function allows the user to add something to the start of the settings
3553       * navigation, which means it will be at the top of the settings navigation block
3554       *
3555       * @param string $text text to be used for the link.
3556       * @param string|moodle_url $url url for the new node
3557       * @param int $type the type of node navigation_node::TYPE_*
3558       * @param string $shorttext
3559       * @param string|int $key a key to access the node by.
3560       * @param pix_icon $icon An icon that appears next to the node.
3561       * @return navigation_node $node with the new node added to it.
3562       */
3563      public function prepend($text, $url=null, $type=null, $shorttext=null, $key=null, pix_icon $icon=null) {
3564          $children = $this->children;
3565          $childrenclass = get_class($children);
3566          $this->children = new $childrenclass;
3567          $node = $this->add($text, $url, $type, $shorttext, $key, $icon);
3568          foreach ($children as $child) {
3569              $this->children->add($child);
3570          }
3571          return $node;
3572      }
3573  
3574      /**
3575       * Does this page require loading of full admin tree or is
3576       * it enough rely on AJAX?
3577       *
3578       * @return bool
3579       */
3580      protected function is_admin_tree_needed() {
3581          if (self::$loadadmintree) {
3582              // Usually external admin page or settings page.
3583              return true;
3584          }
3585  
3586          if ($this->page->pagelayout === 'admin' or strpos($this->page->pagetype, 'admin-') === 0) {
3587              // Admin settings tree is intended for system level settings and management only, use navigation for the rest!
3588              if ($this->page->context->contextlevel != CONTEXT_SYSTEM) {
3589                  return false;
3590              }
3591              return true;
3592          }
3593  
3594          return false;
3595      }
3596  
3597      /**
3598       * Load the site administration tree
3599       *
3600       * This function loads the site administration tree by using the lib/adminlib library functions
3601       *
3602       * @param navigation_node $referencebranch A reference to a branch in the settings
3603       *      navigation tree
3604       * @param part_of_admin_tree $adminbranch The branch to add, if null generate the admin
3605       *      tree and start at the beginning
3606       * @return mixed A key to access the admin tree by
3607       */
3608      protected function load_administration_settings(navigation_node $referencebranch=null, part_of_admin_tree $adminbranch=null) {
3609          global $CFG;
3610  
3611          // Check if we are just starting to generate this navigation.
3612          if ($referencebranch === null) {
3613  
3614              // Require the admin lib then get an admin structure
3615              if (!function_exists('admin_get_root')) {
3616                  require_once($CFG->dirroot.'/lib/adminlib.php');
3617              }
3618              $adminroot = admin_get_root(false, false);
3619              // This is the active section identifier
3620              $this->adminsection = $this->page->url->param('section');
3621  
3622              // Disable the navigation from automatically finding the active node
3623              navigation_node::$autofindactive = false;
3624              $referencebranch = $this->add(get_string('administrationsite'), null, self::TYPE_SITE_ADMIN, null, 'root');
3625              foreach ($adminroot->children as $adminbranch) {
3626                  $this->load_administration_settings($referencebranch, $adminbranch);
3627              }
3628              navigation_node::$autofindactive = true;
3629  
3630              // Use the admin structure to locate the active page
3631              if (!$this->contains_active_node() && $current = $adminroot->locate($this->adminsection, true)) {
3632                  $currentnode = $this;
3633                  while (($pathkey = array_pop($current->path))!==null && $currentnode) {
3634                      $currentnode = $currentnode->get($pathkey);
3635                  }
3636                  if ($currentnode) {
3637                      $currentnode->make_active();
3638                  }
3639              } else {
3640                  $this->scan_for_active_node($referencebranch);
3641              }
3642              return $referencebranch;
3643          } else if ($adminbranch->check_access()) {
3644              // We have a reference branch that we can access and is not hidden `hurrah`
3645              // Now we need to display it and any children it may have
3646              $url = null;
3647              $icon = null;
3648              if ($adminbranch instanceof admin_settingpage) {
3649                  $url = new moodle_url('/'.$CFG->admin.'/settings.php', array('section'=>$adminbranch->name));
3650              } else if ($adminbranch instanceof admin_externalpage) {
3651                  $url = $adminbranch->url;
3652              } else if (!empty($CFG->linkadmincategories) && $adminbranch instanceof admin_category) {
3653                  $url = new moodle_url('/'.$CFG->admin.'/category.php', array('category' => $adminbranch->name));
3654              }
3655  
3656              // Add the branch
3657              $reference = $referencebranch->add($adminbranch->visiblename, $url, self::TYPE_SETTING, null, $adminbranch->name, $icon);
3658  
3659              if ($adminbranch->is_hidden()) {
3660                  if (($adminbranch instanceof admin_externalpage || $adminbranch instanceof admin_settingpage) && $adminbranch->name == $this->adminsection) {
3661                      $reference->add_class('hidden');
3662                  } else {
3663                      $reference->display = false;
3664                  }
3665              }
3666  
3667              // Check if we are generating the admin notifications and whether notificiations exist
3668              if ($adminbranch->name === 'adminnotifications' && admin_critical_warnings_present()) {
3669                  $reference->add_class('criticalnotification');
3670              }
3671              // Check if this branch has children
3672              if ($reference && isset($adminbranch->children) && is_array($adminbranch->children) && count($adminbranch->children)>0) {
3673                  foreach ($adminbranch->children as $branch) {
3674                      // Generate the child branches as well now using this branch as the reference
3675                      $this->load_administration_settings($reference, $branch);
3676                  }
3677              } else {
3678                  $reference->icon = new pix_icon('i/settings', '');
3679              }
3680          }
3681      }
3682  
3683      /**
3684       * This function recursivily scans nodes until it finds the active node or there
3685       * are no more nodes.
3686       * @param navigation_node $node
3687       */
3688      protected function scan_for_active_node(navigation_node $node) {
3689          if (!$node->check_if_active() && $node->children->count()>0) {
3690              foreach ($node->children as &$child) {
3691                  $this->scan_for_active_node($child);
3692              }
3693          }
3694      }
3695  
3696      /**
3697       * Gets a navigation node given an array of keys that represent the path to
3698       * the desired node.
3699       *
3700       * @param array $path
3701       * @return navigation_node|false
3702       */
3703      protected function get_by_path(array $path) {
3704          $node = $this->get(array_shift($path));
3705          foreach ($path as $key) {
3706              $node->get($key);
3707          }
3708          return $node;
3709      }
3710  
3711      /**
3712       * This function loads the course settings that are available for the user
3713       *
3714       * @param bool $forceopen If set to true the course node will be forced open
3715       * @return navigation_node|false
3716       */
3717      protected function load_course_settings($forceopen = false) {
3718          global $CFG;
3719  
3720          $course = $this->page->course