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  • Bug fixes for general core bugs in 3.11.x will end 14 Nov 2022 (12 months plus 6 months extension).
  • Bug fixes for security issues in 3.11.x will end 13 Nov 2023 (18 months plus 12 months extension).
  • PHP version: minimum PHP 7.3.0 Note: minimum PHP version has increased since Moodle 3.10. PHP 7.4.x is supported too.
  • /lib/ -> modinfolib.php (source)

    Differences Between: [Versions 310 and 311] [Versions 311 and 400] [Versions 37 and 311] [Versions 38 and 311] [Versions 39 and 311]

       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   * modinfolib.php - Functions/classes relating to cached information about module instances on
      19   * a course.
      20   * @package    core
      21   * @subpackage lib
      22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
      23   * @author     sam marshall
      24   */
      25  
      26  
      27  // Maximum number of modinfo items to keep in memory cache. Do not increase this to a large
      28  // number because:
      29  // a) modinfo can be big (megabyte range) for some courses
      30  // b) performance of cache will deteriorate if there are very many items in it
      31  if (!defined('MAX_MODINFO_CACHE_SIZE')) {
      32      define('MAX_MODINFO_CACHE_SIZE', 10);
      33  }
      34  
      35  
      36  /**
      37   * Information about a course that is cached in the course table 'modinfo' field (and then in
      38   * memory) in order to reduce the need for other database queries.
      39   *
      40   * This includes information about the course-modules and the sections on the course. It can also
      41   * include dynamic data that has been updated for the current user.
      42   *
      43   * Use {@link get_fast_modinfo()} to retrieve the instance of the object for particular course
      44   * and particular user.
      45   *
      46   * @property-read int $courseid Course ID
      47   * @property-read int $userid User ID
      48   * @property-read array $sections Array from section number (e.g. 0) to array of course-module IDs in that
      49   *     section; this only includes sections that contain at least one course-module
      50   * @property-read cm_info[] $cms Array from course-module instance to cm_info object within this course, in
      51   *     order of appearance
      52   * @property-read cm_info[][] $instances Array from string (modname) => int (instance id) => cm_info object
      53   * @property-read array $groups Groups that the current user belongs to. Calculated on the first request.
      54   *     Is an array of grouping id => array of group id => group id. Includes grouping id 0 for 'all groups'
      55   */
      56  class course_modinfo {
      57      /** @var int Maximum time the course cache building lock can be held */
      58      const COURSE_CACHE_LOCK_EXPIRY = 180;
      59  
      60      /** @var int Time to wait for the course cache building lock before throwing an exception */
      61      const COURSE_CACHE_LOCK_WAIT = 60;
      62  
      63      /**
      64       * List of fields from DB table 'course' that are cached in MUC and are always present in course_modinfo::$course
      65       * @var array
      66       */
      67      public static $cachedfields = array('shortname', 'fullname', 'format',
      68              'enablecompletion', 'groupmode', 'groupmodeforce', 'cacherev');
      69  
      70      /**
      71       * For convenience we store the course object here as it is needed in other parts of code
      72       * @var stdClass
      73       */
      74      private $course;
      75  
      76      /**
      77       * Array of section data from cache
      78       * @var section_info[]
      79       */
      80      private $sectioninfo;
      81  
      82      /**
      83       * User ID
      84       * @var int
      85       */
      86      private $userid;
      87  
      88      /**
      89       * Array from int (section num, e.g. 0) => array of int (course-module id); this list only
      90       * includes sections that actually contain at least one course-module
      91       * @var array
      92       */
      93      private $sections;
      94  
      95      /**
      96       * Array from int (cm id) => cm_info object
      97       * @var cm_info[]
      98       */
      99      private $cms;
     100  
     101      /**
     102       * Array from string (modname) => int (instance id) => cm_info object
     103       * @var cm_info[][]
     104       */
     105      private $instances;
     106  
     107      /**
     108       * Groups that the current user belongs to. This value is calculated on first
     109       * request to the property or function.
     110       * When set, it is an array of grouping id => array of group id => group id.
     111       * Includes grouping id 0 for 'all groups'.
     112       * @var int[][]
     113       */
     114      private $groups;
     115  
     116      /**
     117       * List of class read-only properties and their getter methods.
     118       * Used by magic functions __get(), __isset(), __empty()
     119       * @var array
     120       */
     121      private static $standardproperties = array(
     122          'courseid' => 'get_course_id',
     123          'userid' => 'get_user_id',
     124          'sections' => 'get_sections',
     125          'cms' => 'get_cms',
     126          'instances' => 'get_instances',
     127          'groups' => 'get_groups_all',
     128      );
     129  
     130      /**
     131       * Magic method getter
     132       *
     133       * @param string $name
     134       * @return mixed
     135       */
     136      public function __get($name) {
     137          if (isset(self::$standardproperties[$name])) {
     138              $method = self::$standardproperties[$name];
     139              return $this->$method();
     140          } else {
     141              debugging('Invalid course_modinfo property accessed: '.$name);
     142              return null;
     143          }
     144      }
     145  
     146      /**
     147       * Magic method for function isset()
     148       *
     149       * @param string $name
     150       * @return bool
     151       */
     152      public function __isset($name) {
     153          if (isset(self::$standardproperties[$name])) {
     154              $value = $this->__get($name);
     155              return isset($value);
     156          }
     157          return false;
     158      }
     159  
     160      /**
     161       * Magic method for function empty()
     162       *
     163       * @param string $name
     164       * @return bool
     165       */
     166      public function __empty($name) {
     167          if (isset(self::$standardproperties[$name])) {
     168              $value = $this->__get($name);
     169              return empty($value);
     170          }
     171          return true;
     172      }
     173  
     174      /**
     175       * Magic method setter
     176       *
     177       * Will display the developer warning when trying to set/overwrite existing property.
     178       *
     179       * @param string $name
     180       * @param mixed $value
     181       */
     182      public function __set($name, $value) {
     183          debugging("It is not allowed to set the property course_modinfo::\${$name}", DEBUG_DEVELOPER);
     184      }
     185  
     186      /**
     187       * Returns course object that was used in the first {@link get_fast_modinfo()} call.
     188       *
     189       * It may not contain all fields from DB table {course} but always has at least the following:
     190       * id,shortname,fullname,format,enablecompletion,groupmode,groupmodeforce,cacherev
     191       *
     192       * @return stdClass
     193       */
     194      public function get_course() {
     195          return $this->course;
     196      }
     197  
     198      /**
     199       * @return int Course ID
     200       */
     201      public function get_course_id() {
     202          return $this->course->id;
     203      }
     204  
     205      /**
     206       * @return int User ID
     207       */
     208      public function get_user_id() {
     209          return $this->userid;
     210      }
     211  
     212      /**
     213       * @return array Array from section number (e.g. 0) to array of course-module IDs in that
     214       *   section; this only includes sections that contain at least one course-module
     215       */
     216      public function get_sections() {
     217          return $this->sections;
     218      }
     219  
     220      /**
     221       * @return cm_info[] Array from course-module instance to cm_info object within this course, in
     222       *   order of appearance
     223       */
     224      public function get_cms() {
     225          return $this->cms;
     226      }
     227  
     228      /**
     229       * Obtains a single course-module object (for a course-module that is on this course).
     230       * @param int $cmid Course-module ID
     231       * @return cm_info Information about that course-module
     232       * @throws moodle_exception If the course-module does not exist
     233       */
     234      public function get_cm($cmid) {
     235          if (empty($this->cms[$cmid])) {
     236              throw new moodle_exception('invalidcoursemodule', 'error');
     237          }
     238          return $this->cms[$cmid];
     239      }
     240  
     241      /**
     242       * Obtains all module instances on this course.
     243       * @return cm_info[][] Array from module name => array from instance id => cm_info
     244       */
     245      public function get_instances() {
     246          return $this->instances;
     247      }
     248  
     249      /**
     250       * Returns array of localised human-readable module names used in this course
     251       *
     252       * @param bool $plural if true returns the plural form of modules names
     253       * @return array
     254       */
     255      public function get_used_module_names($plural = false) {
     256          $modnames = get_module_types_names($plural);
     257          $modnamesused = array();
     258          foreach ($this->get_cms() as $cmid => $mod) {
     259              if (!isset($modnamesused[$mod->modname]) && isset($modnames[$mod->modname]) && $mod->uservisible) {
     260                  $modnamesused[$mod->modname] = $modnames[$mod->modname];
     261              }
     262          }
     263          return $modnamesused;
     264      }
     265  
     266      /**
     267       * Obtains all instances of a particular module on this course.
     268       * @param $modname Name of module (not full frankenstyle) e.g. 'label'
     269       * @return cm_info[] Array from instance id => cm_info for modules on this course; empty if none
     270       */
     271      public function get_instances_of($modname) {
     272          if (empty($this->instances[$modname])) {
     273              return array();
     274          }
     275          return $this->instances[$modname];
     276      }
     277  
     278      /**
     279       * Groups that the current user belongs to organised by grouping id. Calculated on the first request.
     280       * @return int[][] array of grouping id => array of group id => group id. Includes grouping id 0 for 'all groups'
     281       */
     282      private function get_groups_all() {
     283          if (is_null($this->groups)) {
     284              // NOTE: Performance could be improved here. The system caches user groups
     285              // in $USER->groupmember[$courseid] => array of groupid=>groupid. Unfortunately this
     286              // structure does not include grouping information. It probably could be changed to
     287              // do so, without a significant performance hit on login, thus saving this one query
     288              // each request.
     289              $this->groups = groups_get_user_groups($this->course->id, $this->userid);
     290          }
     291          return $this->groups;
     292      }
     293  
     294      /**
     295       * Returns groups that the current user belongs to on the course. Note: If not already
     296       * available, this may make a database query.
     297       * @param int $groupingid Grouping ID or 0 (default) for all groups
     298       * @return int[] Array of int (group id) => int (same group id again); empty array if none
     299       */
     300      public function get_groups($groupingid = 0) {
     301          $allgroups = $this->get_groups_all();
     302          if (!isset($allgroups[$groupingid])) {
     303              return array();
     304          }
     305          return $allgroups[$groupingid];
     306      }
     307  
     308      /**
     309       * Gets all sections as array from section number => data about section.
     310       * @return section_info[] Array of section_info objects organised by section number
     311       */
     312      public function get_section_info_all() {
     313          return $this->sectioninfo;
     314      }
     315  
     316      /**
     317       * Gets data about specific numbered section.
     318       * @param int $sectionnumber Number (not id) of section
     319       * @param int $strictness Use MUST_EXIST to throw exception if it doesn't
     320       * @return section_info Information for numbered section or null if not found
     321       */
     322      public function get_section_info($sectionnumber, $strictness = IGNORE_MISSING) {
     323          if (!array_key_exists($sectionnumber, $this->sectioninfo)) {
     324              if ($strictness === MUST_EXIST) {
     325                  throw new moodle_exception('sectionnotexist');
     326              } else {
     327                  return null;
     328              }
     329          }
     330          return $this->sectioninfo[$sectionnumber];
     331      }
     332  
     333      /**
     334       * Static cache for generated course_modinfo instances
     335       *
     336       * @see course_modinfo::instance()
     337       * @see course_modinfo::clear_instance_cache()
     338       * @var course_modinfo[]
     339       */
     340      protected static $instancecache = array();
     341  
     342      /**
     343       * Timestamps (microtime) when the course_modinfo instances were last accessed
     344       *
     345       * It is used to remove the least recent accessed instances when static cache is full
     346       *
     347       * @var float[]
     348       */
     349      protected static $cacheaccessed = array();
     350  
     351      /**
     352       * Clears the cache used in course_modinfo::instance()
     353       *
     354       * Used in {@link get_fast_modinfo()} when called with argument $reset = true
     355       * and in {@link rebuild_course_cache()}
     356       *
     357       * @param null|int|stdClass $courseorid if specified removes only cached value for this course
     358       */
     359      public static function clear_instance_cache($courseorid = null) {
     360          if (empty($courseorid)) {
     361              self::$instancecache = array();
     362              self::$cacheaccessed = array();
     363              return;
     364          }
     365          if (is_object($courseorid)) {
     366              $courseorid = $courseorid->id;
     367          }
     368          if (isset(self::$instancecache[$courseorid])) {
     369              // Unsetting static variable in PHP is peculiar, it removes the reference,
     370              // but data remain in memory. Prior to unsetting, the varable needs to be
     371              // set to empty to remove its remains from memory.
     372              self::$instancecache[$courseorid] = '';
     373              unset(self::$instancecache[$courseorid]);
     374              unset(self::$cacheaccessed[$courseorid]);
     375          }
     376      }
     377  
     378      /**
     379       * Returns the instance of course_modinfo for the specified course and specified user
     380       *
     381       * This function uses static cache for the retrieved instances. The cache
     382       * size is limited by MAX_MODINFO_CACHE_SIZE. If instance is not found in
     383       * the static cache or it was created for another user or the cacherev validation
     384       * failed - a new instance is constructed and returned.
     385       *
     386       * Used in {@link get_fast_modinfo()}
     387       *
     388       * @param int|stdClass $courseorid object from DB table 'course' (must have field 'id'
     389       *     and recommended to have field 'cacherev') or just a course id
     390       * @param int $userid User id to populate 'availble' and 'uservisible' attributes of modules and sections.
     391       *     Set to 0 for current user (default). Set to -1 to avoid calculation of dynamic user-depended data.
     392       * @return course_modinfo
     393       */
     394      public static function instance($courseorid, $userid = 0) {
     395          global $USER;
     396          if (is_object($courseorid)) {
     397              $course = $courseorid;
     398          } else {
     399              $course = (object)array('id' => $courseorid);
     400          }
     401          if (empty($userid)) {
     402              $userid = $USER->id;
     403          }
     404  
     405          if (!empty(self::$instancecache[$course->id])) {
     406              if (self::$instancecache[$course->id]->userid == $userid &&
     407                      (!isset($course->cacherev) ||
     408                      $course->cacherev == self::$instancecache[$course->id]->get_course()->cacherev)) {
     409                  // This course's modinfo for the same user was recently retrieved, return cached.
     410                  self::$cacheaccessed[$course->id] = microtime(true);
     411                  return self::$instancecache[$course->id];
     412              } else {
     413                  // Prevent potential reference problems when switching users.
     414                  self::clear_instance_cache($course->id);
     415              }
     416          }
     417          $modinfo = new course_modinfo($course, $userid);
     418  
     419          // We have a limit of MAX_MODINFO_CACHE_SIZE entries to store in static variable.
     420          if (count(self::$instancecache) >= MAX_MODINFO_CACHE_SIZE) {
     421              // Find the course that was the least recently accessed.
     422              asort(self::$cacheaccessed, SORT_NUMERIC);
     423              $courseidtoremove = key(array_reverse(self::$cacheaccessed, true));
     424              self::clear_instance_cache($courseidtoremove);
     425          }
     426  
     427          // Add modinfo to the static cache.
     428          self::$instancecache[$course->id] = $modinfo;
     429          self::$cacheaccessed[$course->id] = microtime(true);
     430  
     431          return $modinfo;
     432      }
     433  
     434      /**
     435       * Constructs based on course.
     436       * Note: This constructor should not usually be called directly.
     437       * Use get_fast_modinfo($course) instead as this maintains a cache.
     438       * @param stdClass $course course object, only property id is required.
     439       * @param int $userid User ID
     440       * @throws moodle_exception if course is not found
     441       */
     442      public function __construct($course, $userid) {
     443          global $CFG, $COURSE, $SITE, $DB;
     444  
     445          if (!isset($course->cacherev)) {
     446              // We require presence of property cacherev to validate the course cache.
     447              // No need to clone the $COURSE or $SITE object here because we clone it below anyway.
     448              $course = get_course($course->id, false);
     449          }
     450  
     451          $cachecoursemodinfo = cache::make('core', 'coursemodinfo');
     452  
     453          // Retrieve modinfo from cache. If not present or cacherev mismatches, call rebuild and retrieve again.
     454          $coursemodinfo = $cachecoursemodinfo->get($course->id);
     455          if ($coursemodinfo === false || ($course->cacherev != $coursemodinfo->cacherev)) {
     456              $lock = self::get_course_cache_lock($course->id);
     457              try {
     458                  // Only actually do the build if it's still needed after getting the lock (not if
     459                  // somebody else, who might have been holding the lock, built it already).
     460                  $coursemodinfo = $cachecoursemodinfo->get($course->id);
     461                  if ($coursemodinfo === false || ($course->cacherev != $coursemodinfo->cacherev)) {
     462                      $coursemodinfo = self::inner_build_course_cache($course, $lock);
     463                  }
     464              } finally {
     465                  $lock->release();
     466              }
     467          }
     468  
     469          // Set initial values
     470          $this->userid = $userid;
     471          $this->sections = array();
     472          $this->cms = array();
     473          $this->instances = array();
     474          $this->groups = null;
     475  
     476          // If we haven't already preloaded contexts for the course, do it now
     477          // Modules are also cached here as long as it's the first time this course has been preloaded.
     478          context_helper::preload_course($course->id);
     479  
     480          // Quick integrity check: as a result of race conditions modinfo may not be regenerated after the change.
     481          // It is especially dangerous if modinfo contains the deleted course module, as it results in fatal error.
     482          // We can check it very cheap by validating the existence of module context.
     483          if ($course->id == $COURSE->id || $course->id == $SITE->id) {
     484              // Only verify current course (or frontpage) as pages with many courses may not have module contexts cached.
     485              // (Uncached modules will result in a very slow verification).
     486              foreach ($coursemodinfo->modinfo as $mod) {
     487                  if (!context_module::instance($mod->cm, IGNORE_MISSING)) {
     488                      debugging('Course cache integrity check failed: course module with id '. $mod->cm.
     489                              ' does not have context. Rebuilding cache for course '. $course->id);
     490                      // Re-request the course record from DB as well, don't use get_course() here.
     491                      $course = $DB->get_record('course', array('id' => $course->id), '*', MUST_EXIST);
     492                      $coursemodinfo = self::build_course_cache($course);
     493                      break;
     494                  }
     495              }
     496          }
     497  
     498          // Overwrite unset fields in $course object with cached values, store the course object.
     499          $this->course = fullclone($course);
     500          foreach ($coursemodinfo as $key => $value) {
     501              if ($key !== 'modinfo' && $key !== 'sectioncache' &&
     502                      (!isset($this->course->$key) || $key === 'cacherev')) {
     503                  $this->course->$key = $value;
     504              }
     505          }
     506  
     507          // Loop through each piece of module data, constructing it
     508          static $modexists = array();
     509          foreach ($coursemodinfo->modinfo as $mod) {
     510              if (!isset($mod->name) || strval($mod->name) === '') {
     511                  // something is wrong here
     512                  continue;
     513              }
     514  
     515              // Skip modules which don't exist
     516              if (!array_key_exists($mod->mod, $modexists)) {
     517                  $modexists[$mod->mod] = file_exists("$CFG->dirroot/mod/$mod->mod/lib.php");
     518              }
     519              if (!$modexists[$mod->mod]) {
     520                  continue;
     521              }
     522  
     523              // Construct info for this module
     524              $cm = new cm_info($this, null, $mod, null);
     525  
     526              // Store module in instances and cms array
     527              if (!isset($this->instances[$cm->modname])) {
     528                  $this->instances[$cm->modname] = array();
     529              }
     530              $this->instances[$cm->modname][$cm->instance] = $cm;
     531              $this->cms[$cm->id] = $cm;
     532  
     533              // Reconstruct sections. This works because modules are stored in order
     534              if (!isset($this->sections[$cm->sectionnum])) {
     535                  $this->sections[$cm->sectionnum] = array();
     536              }
     537              $this->sections[$cm->sectionnum][] = $cm->id;
     538          }
     539  
     540          // Expand section objects
     541          $this->sectioninfo = array();
     542          foreach ($coursemodinfo->sectioncache as $number => $data) {
     543              $this->sectioninfo[$number] = new section_info($data, $number, null, null,
     544                      $this, null);
     545          }
     546      }
     547  
     548      /**
     549       * This method can not be used anymore.
     550       *
     551       * @see course_modinfo::build_course_cache()
     552       * @deprecated since 2.6
     553       */
     554      public static function build_section_cache($courseid) {
     555          throw new coding_exception('Function course_modinfo::build_section_cache() can not be used anymore.' .
     556              ' Please use course_modinfo::build_course_cache() whenever applicable.');
     557      }
     558  
     559      /**
     560       * Builds a list of information about sections on a course to be stored in
     561       * the course cache. (Does not include information that is already cached
     562       * in some other way.)
     563       *
     564       * @param stdClass $course Course object (must contain fields
     565       * @return array Information about sections, indexed by section number (not id)
     566       */
     567      protected static function build_course_section_cache($course) {
     568          global $DB;
     569  
     570          // Get section data
     571          $sections = $DB->get_records('course_sections', array('course' => $course->id), 'section',
     572                  'section, id, course, name, summary, summaryformat, sequence, visible, availability');
     573          $compressedsections = array();
     574  
     575          $formatoptionsdef = course_get_format($course)->section_format_options();
     576          // Remove unnecessary data and add availability
     577          foreach ($sections as $number => $section) {
     578              // Add cached options from course format to $section object
     579              foreach ($formatoptionsdef as $key => $option) {
     580                  if (!empty($option['cache'])) {
     581                      $formatoptions = course_get_format($course)->get_format_options($section);
     582                      if (!array_key_exists('cachedefault', $option) || $option['cachedefault'] !== $formatoptions[$key]) {
     583                          $section->$key = $formatoptions[$key];
     584                      }
     585                  }
     586              }
     587              // Clone just in case it is reused elsewhere
     588              $compressedsections[$number] = clone($section);
     589              section_info::convert_for_section_cache($compressedsections[$number]);
     590          }
     591  
     592          return $compressedsections;
     593      }
     594  
     595      /**
     596       * Gets a lock for rebuilding the cache of a single course.
     597       *
     598       * Caller must release the returned lock.
     599       *
     600       * This is used to ensure that the cache rebuild doesn't happen multiple times in parallel.
     601       * This function will wait up to 1 minute for the lock to be obtained. If the lock cannot
     602       * be obtained, it throws an exception.
     603       *
     604       * @param int $courseid Course id
     605       * @return \core\lock\lock Lock (must be released!)
     606       * @throws moodle_exception If the lock cannot be obtained
     607       */
     608      protected static function get_course_cache_lock($courseid) {
     609          // Get database lock to ensure this doesn't happen multiple times in parallel. Wait a
     610          // reasonable time for the lock to be released, so we can give a suitable error message.
     611          // In case the system crashes while building the course cache, the lock will automatically
     612          // expire after a (slightly longer) period.
     613          $lockfactory = \core\lock\lock_config::get_lock_factory('core_modinfo');
     614          $lock = $lockfactory->get_lock('build_course_cache_' . $courseid,
     615                  self::COURSE_CACHE_LOCK_WAIT, self::COURSE_CACHE_LOCK_EXPIRY);
     616          if (!$lock) {
     617              throw new moodle_exception('locktimeout', '', '', null,
     618                      'core_modinfo/build_course_cache_' . $courseid);
     619          }
     620          return $lock;
     621      }
     622  
     623      /**
     624       * Builds and stores in MUC object containing information about course
     625       * modules and sections together with cached fields from table course.
     626       *
     627       * @param stdClass $course object from DB table course. Must have property 'id'
     628       *     but preferably should have all cached fields.
     629       * @return stdClass object with all cached keys of the course plus fields modinfo and sectioncache.
     630       *     The same object is stored in MUC
     631       * @throws moodle_exception if course is not found (if $course object misses some of the
     632       *     necessary fields it is re-requested from database)
     633       */
     634      public static function build_course_cache($course) {
     635          if (empty($course->id)) {
     636              throw new coding_exception('Object $course is missing required property \id\'');
     637          }
     638  
     639          $lock = self::get_course_cache_lock($course->id);
     640          try {
     641              return self::inner_build_course_cache($course, $lock);
     642          } finally {
     643              $lock->release();
     644          }
     645      }
     646  
     647      /**
     648       * Called to build course cache when there is already a lock obtained.
     649       *
     650       * @param stdClass $course object from DB table course
     651       * @param \core\lock\lock $lock Lock object - not actually used, just there to indicate you have a lock
     652       * @return stdClass Course object that has been stored in MUC
     653       */
     654      protected static function inner_build_course_cache($course, \core\lock\lock $lock) {
     655          global $DB, $CFG;
     656          require_once("{$CFG->dirroot}/course/lib.php");
     657  
     658          // Ensure object has all necessary fields.
     659          foreach (self::$cachedfields as $key) {
     660              if (!isset($course->$key)) {
     661                  $course = $DB->get_record('course', array('id' => $course->id),
     662                          implode(',', array_merge(array('id'), self::$cachedfields)), MUST_EXIST);
     663                  break;
     664              }
     665          }
     666          // Retrieve all information about activities and sections.
     667          // This may take time on large courses and it is possible that another user modifies the same course during this process.
     668          // Field cacherev stored in both DB and cache will ensure that cached data matches the current course state.
     669          $coursemodinfo = new stdClass();
     670          $coursemodinfo->modinfo = self::get_array_of_activities($course);
     671          $coursemodinfo->sectioncache = self::build_course_section_cache($course);
     672          foreach (self::$cachedfields as $key) {
     673              $coursemodinfo->$key = $course->$key;
     674          }
     675          // Set the accumulated activities and sections information in cache, together with cacherev.
     676          $cachecoursemodinfo = cache::make('core', 'coursemodinfo');
     677          $cachecoursemodinfo->set($course->id, $coursemodinfo);
     678          return $coursemodinfo;
     679      }
     680  
     681      /**
     682       * For a given course, returns an array of course activity objects
     683       *
     684       * @param stdClass $course Course object
     685       * @return array list of activities
     686       */
     687      public static function get_array_of_activities(stdClass $course): array {
     688          global $CFG, $DB;
     689  
     690          if (empty($course)) {
     691              throw new moodle_exception('courseidnotfound');
     692          }
     693  
     694          $mod = [];
     695  
     696          $rawmods = get_course_mods($course->id);
     697          if (empty($rawmods)) {
     698              return $mod; // always return array
     699          }
     700          $courseformat = course_get_format($course);
     701  
     702          if ($sections = $DB->get_records('course_sections', ['course' => $course->id],
     703              'section ASC', 'id,section,sequence,visible')) {
     704              // First check and correct obvious mismatches between course_sections.sequence and course_modules.section.
     705              if ($errormessages = course_integrity_check($course->id, $rawmods, $sections)) {
     706                  debugging(join('<br>', $errormessages));
     707                  $rawmods = get_course_mods($course->id);
     708                  $sections = $DB->get_records('course_sections', ['course' => $course->id],
     709                      'section ASC', 'id,section,sequence,visible');
     710              }
     711              // Build array of activities.
     712              foreach ($sections as $section) {
     713                  if (!empty($section->sequence)) {
     714                      $sequence = explode(",", $section->sequence);
     715                      foreach ($sequence as $seq) {
     716                          if (empty($rawmods[$seq])) {
     717                              continue;
     718                          }
     719                          // Adjust visibleoncoursepage, value in DB may not respect format availability.
     720                          $rawmods[$seq]->visibleoncoursepage = (!$rawmods[$seq]->visible
     721                              || $rawmods[$seq]->visibleoncoursepage
     722                              || empty($CFG->allowstealth)
     723                              || !$courseformat->allow_stealth_module_visibility($rawmods[$seq], $section)) ? 1 : 0;
     724  
     725                          // Create an object that will be cached.
     726                          $mod[$seq] = new stdClass();
     727                          $mod[$seq]->id = $rawmods[$seq]->instance;
     728                          $mod[$seq]->cm = $rawmods[$seq]->id;
     729                          $mod[$seq]->mod = $rawmods[$seq]->modname;
     730  
     731                          // Oh dear. Inconsistent names left here for backward compatibility.
     732                          $mod[$seq]->section = $section->section;
     733                          $mod[$seq]->sectionid = $rawmods[$seq]->section;
     734  
     735                          $mod[$seq]->module = $rawmods[$seq]->module;
     736                          $mod[$seq]->added = $rawmods[$seq]->added;
     737                          $mod[$seq]->score = $rawmods[$seq]->score;
     738                          $mod[$seq]->idnumber = $rawmods[$seq]->idnumber;
     739                          $mod[$seq]->visible = $rawmods[$seq]->visible;
     740                          $mod[$seq]->visibleoncoursepage = $rawmods[$seq]->visibleoncoursepage;
     741                          $mod[$seq]->visibleold = $rawmods[$seq]->visibleold;
     742                          $mod[$seq]->groupmode = $rawmods[$seq]->groupmode;
     743                          $mod[$seq]->groupingid = $rawmods[$seq]->groupingid;
     744                          $mod[$seq]->indent = $rawmods[$seq]->indent;
     745                          $mod[$seq]->completion = $rawmods[$seq]->completion;
     746                          $mod[$seq]->extra = "";
     747                          $mod[$seq]->completiongradeitemnumber =
     748                              $rawmods[$seq]->completiongradeitemnumber;
     749                          $mod[$seq]->completionview = $rawmods[$seq]->completionview;
     750                          $mod[$seq]->completionexpected = $rawmods[$seq]->completionexpected;
     751                          $mod[$seq]->showdescription = $rawmods[$seq]->showdescription;
     752                          $mod[$seq]->availability = $rawmods[$seq]->availability;
     753                          $mod[$seq]->deletioninprogress = $rawmods[$seq]->deletioninprogress;
     754  
     755                          $modname = $mod[$seq]->mod;
     756                          $functionname = $modname . "_get_coursemodule_info";
     757  
     758                          if (!file_exists("$CFG->dirroot/mod/$modname/lib.php")) {
     759                              continue;
     760                          }
     761  
     762                          include_once("$CFG->dirroot/mod/$modname/lib.php");
     763  
     764                          if ($hasfunction = function_exists($functionname)) {
     765                              if ($info = $functionname($rawmods[$seq])) {
     766                                  if (!empty($info->icon)) {
     767                                      $mod[$seq]->icon = $info->icon;
     768                                  }
     769                                  if (!empty($info->iconcomponent)) {
     770                                      $mod[$seq]->iconcomponent = $info->iconcomponent;
     771                                  }
     772                                  if (!empty($info->name)) {
     773                                      $mod[$seq]->name = $info->name;
     774                                  }
     775                                  if ($info instanceof cached_cm_info) {
     776                                      // When using cached_cm_info you can include three new fields
     777                                      // that aren't available for legacy code
     778                                      if (!empty($info->content)) {
     779                                          $mod[$seq]->content = $info->content;
     780                                      }
     781                                      if (!empty($info->extraclasses)) {
     782                                          $mod[$seq]->extraclasses = $info->extraclasses;
     783                                      }
     784                                      if (!empty($info->iconurl)) {
     785                                          // Convert URL to string as it's easier to store. Also serialized object contains \0 byte and can not be written to Postgres DB.
     786                                          $url = new moodle_url($info->iconurl);
     787                                          $mod[$seq]->iconurl = $url->out(false);
     788                                      }
     789                                      if (!empty($info->onclick)) {
     790                                          $mod[$seq]->onclick = $info->onclick;
     791                                      }
     792                                      if (!empty($info->customdata)) {
     793                                          $mod[$seq]->customdata = $info->customdata;
     794                                      }
     795                                  } else {
     796                                      // When using a stdclass, the (horrible) deprecated ->extra field
     797                                      // is available for BC
     798                                      if (!empty($info->extra)) {
     799                                          $mod[$seq]->extra = $info->extra;
     800                                      }
     801                                  }
     802                              }
     803                          }
     804                          // When there is no modname_get_coursemodule_info function,
     805                          // but showdescriptions is enabled, then we use the 'intro'
     806                          // and 'introformat' fields in the module table
     807                          if (!$hasfunction && $rawmods[$seq]->showdescription) {
     808                              if ($modvalues = $DB->get_record($rawmods[$seq]->modname,
     809                                  ['id' => $rawmods[$seq]->instance], 'name, intro, introformat')) {
     810                                  // Set content from intro and introformat. Filters are disabled
     811                                  // because we  filter it with format_text at display time
     812                                  $mod[$seq]->content = format_module_intro($rawmods[$seq]->modname,
     813                                      $modvalues, $rawmods[$seq]->id, false);
     814  
     815                                  // To save making another query just below, put name in here
     816                                  $mod[$seq]->name = $modvalues->name;
     817                              }
     818                          }
     819                          if (!isset($mod[$seq]->name)) {
     820                              $mod[$seq]->name =
     821                                  $DB->get_field($rawmods[$seq]->modname, "name", ["id" => $rawmods[$seq]->instance]);
     822                          }
     823  
     824                          // Minimise the database size by unsetting default options when they are
     825                          // 'empty'. This list corresponds to code in the cm_info constructor.
     826                          foreach (['idnumber', 'groupmode', 'groupingid',
     827                              'indent', 'completion', 'extra', 'extraclasses', 'iconurl', 'onclick', 'content',
     828                              'icon', 'iconcomponent', 'customdata', 'availability', 'completionview',
     829                              'completionexpected', 'score', 'showdescription', 'deletioninprogress'] as $property) {
     830                              if (property_exists($mod[$seq], $property) &&
     831                                  empty($mod[$seq]->{$property})) {
     832                                  unset($mod[$seq]->{$property});
     833                              }
     834                          }
     835                          // Special case: this value is usually set to null, but may be 0
     836                          if (property_exists($mod[$seq], 'completiongradeitemnumber') &&
     837                              is_null($mod[$seq]->completiongradeitemnumber)) {
     838                              unset($mod[$seq]->completiongradeitemnumber);
     839                          }
     840                      }
     841                  }
     842              }
     843          }
     844          return $mod;
     845      }
     846  
     847      /**
     848       * Purge the cache of a given course
     849       *
     850       * @param int $courseid Course id
     851       */
     852      public static function purge_course_cache(int $courseid): void {
     853          $cachemodinfo = cache::make('core', 'coursemodinfo');
     854          $cachemodinfo->delete($courseid);
     855      }
     856  }
     857  
     858  
     859  /**
     860   * Data about a single module on a course. This contains most of the fields in the course_modules
     861   * table, plus additional data when required.
     862   *
     863   * The object can be accessed by core or any plugin (i.e. course format, block, filter, etc.) as
     864   * get_fast_modinfo($courseorid)->cms[$coursemoduleid]
     865   * or
     866   * get_fast_modinfo($courseorid)->instances[$moduletype][$instanceid]
     867   *
     868   * There are three stages when activity module can add/modify data in this object:
     869   *
     870   * <b>Stage 1 - during building the cache.</b>
     871   * Allows to add to the course cache static user-independent information about the module.
     872   * Modules should try to include only absolutely necessary information that may be required
     873   * when displaying course view page. The information is stored in application-level cache
     874   * and reset when {@link rebuild_course_cache()} is called or cache is purged by admin.
     875   *
     876   * Modules can implement callback XXX_get_coursemodule_info() returning instance of object
     877   * {@link cached_cm_info}
     878   *
     879   * <b>Stage 2 - dynamic data.</b>
     880   * Dynamic data is user-dependent, it is stored in request-level cache. To reset this cache
     881   * {@link get_fast_modinfo()} with $reset argument may be called.
     882   *
     883   * Dynamic data is obtained when any of the following properties/methods is requested:
     884   * - {@link cm_info::$url}
     885   * - {@link cm_info::$name}
     886   * - {@link cm_info::$onclick}
     887   * - {@link cm_info::get_icon_url()}
     888   * - {@link cm_info::$uservisible}
     889   * - {@link cm_info::$available}
     890   * - {@link cm_info::$availableinfo}
     891   * - plus any of the properties listed in Stage 3.
     892   *
     893   * Modules can implement callback <b>XXX_cm_info_dynamic()</b> and inside this callback they
     894   * are allowed to use any of the following set methods:
     895   * - {@link cm_info::set_available()}
     896   * - {@link cm_info::set_name()}
     897   * - {@link cm_info::set_no_view_link()}
     898   * - {@link cm_info::set_user_visible()}
     899   * - {@link cm_info::set_on_click()}
     900   * - {@link cm_info::set_icon_url()}
     901   * - {@link cm_info::override_customdata()}
     902   * Any methods affecting view elements can also be set in this callback.
     903   *
     904   * <b>Stage 3 (view data).</b>
     905   * Also user-dependend data stored in request-level cache. Second stage is created
     906   * because populating the view data can be expensive as it may access much more
     907   * Moodle APIs such as filters, user information, output renderers and we
     908   * don't want to request it until necessary.
     909   * View data is obtained when any of the following properties/methods is requested:
     910   * - {@link cm_info::$afterediticons}
     911   * - {@link cm_info::$content}
     912   * - {@link cm_info::get_formatted_content()}
     913   * - {@link cm_info::$extraclasses}
     914   * - {@link cm_info::$afterlink}
     915   *
     916   * Modules can implement callback <b>XXX_cm_info_view()</b> and inside this callback they
     917   * are allowed to use any of the following set methods:
     918   * - {@link cm_info::set_after_edit_icons()}
     919   * - {@link cm_info::set_after_link()}
     920   * - {@link cm_info::set_content()}
     921   * - {@link cm_info::set_extra_classes()}
     922   *
     923   * @property-read int $id Course-module ID - from course_modules table
     924   * @property-read int $instance Module instance (ID within module table) - from course_modules table
     925   * @property-read int $course Course ID - from course_modules table
     926   * @property-read string $idnumber 'ID number' from course-modules table (arbitrary text set by user) - from
     927   *    course_modules table
     928   * @property-read int $added Time that this course-module was added (unix time) - from course_modules table
     929   * @property-read int $visible Visible setting (0 or 1; if this is 0, students cannot see/access the activity) - from
     930   *    course_modules table
     931   * @property-read int $visibleoncoursepage Visible on course page setting - from course_modules table, adjusted to
     932   *    whether course format allows this module to have the "stealth" mode
     933   * @property-read int $visibleold Old visible setting (if the entire section is hidden, the previous value for
     934   *    visible is stored in this field) - from course_modules table
     935   * @property-read int $groupmode Group mode (one of the constants NOGROUPS, SEPARATEGROUPS, or VISIBLEGROUPS) - from
     936   *    course_modules table. Use {@link cm_info::$effectivegroupmode} to find the actual group mode that may be forced by course.
     937   * @property-read int $groupingid Grouping ID (0 = all groupings)
     938   * @property-read bool $coursegroupmodeforce Indicates whether the course containing the module has forced the groupmode
     939   *    This means that cm_info::$groupmode should be ignored and cm_info::$coursegroupmode be used instead
     940   * @property-read int $coursegroupmode Group mode (one of the constants NOGROUPS, SEPARATEGROUPS, or VISIBLEGROUPS) - from
     941   *    course table - as specified for the course containing the module
     942   *    Effective only if {@link cm_info::$coursegroupmodeforce} is set
     943   * @property-read int $effectivegroupmode Effective group mode for this module (one of the constants NOGROUPS, SEPARATEGROUPS,
     944   *    or VISIBLEGROUPS). This can be different from groupmode set for the module if the groupmode is forced for the course.
     945   *    This value will always be NOGROUPS if module type does not support group mode.
     946   * @property-read int $indent Indent level on course page (0 = no indent) - from course_modules table
     947   * @property-read int $completion Activity completion setting for this activity, COMPLETION_TRACKING_xx constant - from
     948   *    course_modules table
     949   * @property-read mixed $completiongradeitemnumber Set to the item number (usually 0) if completion depends on a particular
     950   *    grade of this activity, or null if completion does not depend on a grade - from course_modules table
     951   * @property-read int $completionview 1 if 'on view' completion is enabled, 0 otherwise - from course_modules table
     952   * @property-read int $completionexpected Set to a unix time if completion of this activity is expected at a
     953   *    particular time, 0 if no time set - from course_modules table
     954   * @property-read string $availability Availability information as JSON string or null if none -
     955   *    from course_modules table
     956   * @property-read int $showdescription Controls whether the description of the activity displays on the course main page (in
     957   *    addition to anywhere it might display within the activity itself). 0 = do not show
     958   *    on main page, 1 = show on main page.
     959   * @property-read string $extra (deprecated) Extra HTML that is put in an unhelpful part of the HTML when displaying this module in
     960   *    course page - from cached data in modinfo field. Deprecated, replaced by ->extraclasses and ->onclick
     961   * @property-read string $icon Name of icon to use - from cached data in modinfo field
     962   * @property-read string $iconcomponent Component that contains icon - from cached data in modinfo field
     963   * @property-read string $modname Name of module e.g. 'forum' (this is the same name as the module's main database
     964   *    table) - from cached data in modinfo field
     965   * @property-read int $module ID of module type - from course_modules table
     966   * @property-read string $name Name of module instance for display on page e.g. 'General discussion forum' - from cached
     967   *    data in modinfo field
     968   * @property-read int $sectionnum Section number that this course-module is in (section 0 = above the calendar, section 1
     969   *    = week/topic 1, etc) - from cached data in modinfo field
     970   * @property-read int $section Section id - from course_modules table
     971   * @property-read array $conditionscompletion Availability conditions for this course-module based on the completion of other
     972   *    course-modules (array from other course-module id to required completion state for that
     973   *    module) - from cached data in modinfo field
     974   * @property-read array $conditionsgrade Availability conditions for this course-module based on course grades (array from
     975   *    grade item id to object with ->min, ->max fields) - from cached data in modinfo field
     976   * @property-read array $conditionsfield Availability conditions for this course-module based on user fields
     977   * @property-read bool $available True if this course-module is available to students i.e. if all availability conditions
     978   *    are met - obtained dynamically
     979   * @property-read string $availableinfo If course-module is not available to students, this string gives information about
     980   *    availability which can be displayed to students and/or staff (e.g. 'Available from 3
     981   *    January 2010') for display on main page - obtained dynamically
     982   * @property-read bool $uservisible True if this course-module is available to the CURRENT user (for example, if current user
     983   *    has viewhiddenactivities capability, they can access the course-module even if it is not
     984   *    visible or not available, so this would be true in that case)
     985   * @property-read context_module $context Module context
     986   * @property-read string $modfullname Returns a localised human-readable name of the module type - calculated on request
     987   * @property-read string $modplural Returns a localised human-readable name of the module type in plural form - calculated on request
     988   * @property-read string $content Content to display on main (view) page - calculated on request
     989   * @property-read moodle_url $url URL to link to for this module, or null if it doesn't have a view page - calculated on request
     990   * @property-read string $extraclasses Extra CSS classes to add to html output for this activity on main page - calculated on request
     991   * @property-read string $onclick Content of HTML on-click attribute already escaped - calculated on request
     992   * @property-read mixed $customdata Optional custom data stored in modinfo cache for this activity, or null if none
     993   * @property-read string $afterlink Extra HTML code to display after link - calculated on request
     994   * @property-read string $afterediticons Extra HTML code to display after editing icons (e.g. more icons) - calculated on request
     995   * @property-read bool $deletioninprogress True if this course module is scheduled for deletion, false otherwise.
     996   */
     997  class cm_info implements IteratorAggregate {
     998      /**
     999       * State: Only basic data from modinfo cache is available.
    1000       */
    1001      const STATE_BASIC = 0;
    1002  
    1003      /**
    1004       * State: In the process of building dynamic data (to avoid recursive calls to obtain_dynamic_data())
    1005       */
    1006      const STATE_BUILDING_DYNAMIC = 1;
    1007  
    1008      /**
    1009       * State: Dynamic data is available too.
    1010       */
    1011      const STATE_DYNAMIC = 2;
    1012  
    1013      /**
    1014       * State: In the process of building view data (to avoid recursive calls to obtain_view_data())
    1015       */
    1016      const STATE_BUILDING_VIEW = 3;
    1017  
    1018      /**
    1019       * State: View data (for course page) is available.
    1020       */
    1021      const STATE_VIEW = 4;
    1022  
    1023      /**
    1024       * Parent object
    1025       * @var course_modinfo
    1026       */
    1027      private $modinfo;
    1028  
    1029      /**
    1030       * Level of information stored inside this object (STATE_xx constant)
    1031       * @var int
    1032       */
    1033      private $state;
    1034  
    1035      /**
    1036       * Course-module ID - from course_modules table
    1037       * @var int
    1038       */
    1039      private $id;
    1040  
    1041      /**
    1042       * Module instance (ID within module table) - from course_modules table
    1043       * @var int
    1044       */
    1045      private $instance;
    1046  
    1047      /**
    1048       * 'ID number' from course-modules table (arbitrary text set by user) - from
    1049       * course_modules table
    1050       * @var string
    1051       */
    1052      private $idnumber;
    1053  
    1054      /**
    1055       * Time that this course-module was added (unix time) - from course_modules table
    1056       * @var int
    1057       */
    1058      private $added;
    1059  
    1060      /**
    1061       * This variable is not used and is included here only so it can be documented.
    1062       * Once the database entry is removed from course_modules, it should be deleted
    1063       * here too.
    1064       * @var int
    1065       * @deprecated Do not use this variable
    1066       */
    1067      private $score;
    1068  
    1069      /**
    1070       * Visible setting (0 or 1; if this is 0, students cannot see/access the activity) - from
    1071       * course_modules table
    1072       * @var int
    1073       */
    1074      private $visible;
    1075  
    1076      /**
    1077       * Visible on course page setting - from course_modules table
    1078       * @var int
    1079       */
    1080      private $visibleoncoursepage;
    1081  
    1082      /**
    1083       * Old visible setting (if the entire section is hidden, the previous value for
    1084       * visible is stored in this field) - from course_modules table
    1085       * @var int
    1086       */
    1087      private $visibleold;
    1088  
    1089      /**
    1090       * Group mode (one of the constants NONE, SEPARATEGROUPS, or VISIBLEGROUPS) - from
    1091       * course_modules table
    1092       * @var int
    1093       */
    1094      private $groupmode;
    1095  
    1096      /**
    1097       * Grouping ID (0 = all groupings)
    1098       * @var int
    1099       */
    1100      private $groupingid;
    1101  
    1102      /**
    1103       * Indent level on course page (0 = no indent) - from course_modules table
    1104       * @var int
    1105       */
    1106      private $indent;
    1107  
    1108      /**
    1109       * Activity completion setting for this activity, COMPLETION_TRACKING_xx constant - from
    1110       * course_modules table
    1111       * @var int
    1112       */
    1113      private $completion;
    1114  
    1115      /**
    1116       * Set to the item number (usually 0) if completion depends on a particular
    1117       * grade of this activity, or null if completion does not depend on a grade - from
    1118       * course_modules table
    1119       * @var mixed
    1120       */
    1121      private $completiongradeitemnumber;
    1122  
    1123      /**
    1124       * 1 if 'on view' completion is enabled, 0 otherwise - from course_modules table
    1125       * @var int
    1126       */
    1127      private $completionview;
    1128  
    1129      /**
    1130       * Set to a unix time if completion of this activity is expected at a
    1131       * particular time, 0 if no time set - from course_modules table
    1132       * @var int
    1133       */
    1134      private $completionexpected;
    1135  
    1136      /**
    1137       * Availability information as JSON string or null if none - from course_modules table
    1138       * @var string
    1139       */
    1140      private $availability;
    1141  
    1142      /**
    1143       * Controls whether the description of the activity displays on the course main page (in
    1144       * addition to anywhere it might display within the activity itself). 0 = do not show
    1145       * on main page, 1 = show on main page.
    1146       * @var int
    1147       */
    1148      private $showdescription;
    1149  
    1150      /**
    1151       * Extra HTML that is put in an unhelpful part of the HTML when displaying this module in
    1152       * course page - from cached data in modinfo field
    1153       * @deprecated This is crazy, don't use it. Replaced by ->extraclasses and ->onclick
    1154       * @var string
    1155       */
    1156      private $extra;
    1157  
    1158      /**
    1159       * Name of icon to use - from cached data in modinfo field
    1160       * @var string
    1161       */
    1162      private $icon;
    1163  
    1164      /**
    1165       * Component that contains icon - from cached data in modinfo field
    1166       * @var string
    1167       */
    1168      private $iconcomponent;
    1169  
    1170      /**
    1171       * Name of module e.g. 'forum' (this is the same name as the module's main database
    1172       * table) - from cached data in modinfo field
    1173       * @var string
    1174       */
    1175      private $modname;
    1176  
    1177      /**
    1178       * ID of module - from course_modules table
    1179       * @var int
    1180       */
    1181      private $module;
    1182  
    1183      /**
    1184       * Name of module instance for display on page e.g. 'General discussion forum' - from cached
    1185       * data in modinfo field
    1186       * @var string
    1187       */
    1188      private $name;
    1189  
    1190      /**
    1191       * Section number that this course-module is in (section 0 = above the calendar, section 1
    1192       * = week/topic 1, etc) - from cached data in modinfo field
    1193       * @var int
    1194       */
    1195      private $sectionnum;
    1196  
    1197      /**
    1198       * Section id - from course_modules table
    1199       * @var int
    1200       */
    1201      private $section;
    1202  
    1203      /**
    1204       * Availability conditions for this course-module based on the completion of other
    1205       * course-modules (array from other course-module id to required completion state for that
    1206       * module) - from cached data in modinfo field
    1207       * @var array
    1208       */
    1209      private $conditionscompletion;
    1210  
    1211      /**
    1212       * Availability conditions for this course-module based on course grades (array from
    1213       * grade item id to object with ->min, ->max fields) - from cached data in modinfo field
    1214       * @var array
    1215       */
    1216      private $conditionsgrade;
    1217  
    1218      /**
    1219       * Availability conditions for this course-module based on user fields
    1220       * @var array
    1221       */
    1222      private $conditionsfield;
    1223  
    1224      /**
    1225       * True if this course-module is available to students i.e. if all availability conditions
    1226       * are met - obtained dynamically
    1227       * @var bool
    1228       */
    1229      private $available;
    1230  
    1231      /**
    1232       * If course-module is not available to students, this string gives information about
    1233       * availability which can be displayed to students and/or staff (e.g. 'Available from 3
    1234       * January 2010') for display on main page - obtained dynamically
    1235       * @var string
    1236       */
    1237      private $availableinfo;
    1238  
    1239      /**
    1240       * True if this course-module is available to the CURRENT user (for example, if current user
    1241       * has viewhiddenactivities capability, they can access the course-module even if it is not
    1242       * visible or not available, so this would be true in that case)
    1243       * @var bool
    1244       */
    1245      private $uservisible;
    1246  
    1247      /**
    1248       * True if this course-module is visible to the CURRENT user on the course page
    1249       * @var bool
    1250       */
    1251      private $uservisibleoncoursepage;
    1252  
    1253      /**
    1254       * @var moodle_url
    1255       */
    1256      private $url;
    1257  
    1258      /**
    1259       * @var string
    1260       */
    1261      private $content;
    1262  
    1263      /**
    1264       * @var bool
    1265       */
    1266      private $contentisformatted;
    1267  
    1268      /**
    1269       * @var string
    1270       */
    1271      private $extraclasses;
    1272  
    1273      /**
    1274       * @var moodle_url full external url pointing to icon image for activity
    1275       */
    1276      private $iconurl;
    1277  
    1278      /**
    1279       * @var string
    1280       */
    1281      private $onclick;
    1282  
    1283      /**
    1284       * @var mixed
    1285       */
    1286      private $customdata;
    1287  
    1288      /**
    1289       * @var string
    1290       */
    1291      private $afterlink;
    1292  
    1293      /**
    1294       * @var string
    1295       */
    1296      private $afterediticons;
    1297  
    1298      /**
    1299       * @var bool representing the deletion state of the module. True if the mod is scheduled for deletion.
    1300       */
    1301      private $deletioninprogress;
    1302  
    1303      /**
    1304       * List of class read-only properties and their getter methods.
    1305       * Used by magic functions __get(), __isset(), __empty()
    1306       * @var array
    1307       */
    1308      private static $standardproperties = array(
    1309          'url' => 'get_url',
    1310          'content' => 'get_content',
    1311          'extraclasses' => 'get_extra_classes',
    1312          'onclick' => 'get_on_click',
    1313          'customdata' => 'get_custom_data',
    1314          'afterlink' => 'get_after_link',
    1315          'afterediticons' => 'get_after_edit_icons',
    1316          'modfullname' => 'get_module_type_name',
    1317          'modplural' => 'get_module_type_name_plural',
    1318          'id' => false,
    1319          'added' => false,
    1320          'availability' => false,
    1321          'available' => 'get_available',
    1322          'availableinfo' => 'get_available_info',
    1323          'completion' => false,
    1324          'completionexpected' => false,
    1325          'completiongradeitemnumber' => false,
    1326          'completionview' => false,
    1327          'conditionscompletion' => false,
    1328          'conditionsfield' => false,
    1329          'conditionsgrade' => false,
    1330          'context' => 'get_context',
    1331          'course' => 'get_course_id',
    1332          'coursegroupmode' => 'get_course_groupmode',
    1333          'coursegroupmodeforce' => 'get_course_groupmodeforce',
    1334          'effectivegroupmode' => 'get_effective_groupmode',
    1335          'extra' => false,
    1336          'groupingid' => false,
    1337          'groupmembersonly' => 'get_deprecated_group_members_only',
    1338          'groupmode' => false,
    1339          'icon' => false,
    1340          'iconcomponent' => false,
    1341          'idnumber' => false,
    1342          'indent' => false,
    1343          'instance' => false,
    1344          'modname' => false,
    1345          'module' => false,
    1346          'name' => 'get_name',
    1347          'score' => false,
    1348          'section' => false,
    1349          'sectionnum' => false,
    1350          'showdescription' => false,
    1351          'uservisible' => 'get_user_visible',
    1352          'visible' => false,
    1353          'visibleoncoursepage' => false,
    1354          'visibleold' => false,
    1355          'deletioninprogress' => false
    1356      );
    1357  
    1358      /**
    1359       * List of methods with no arguments that were public prior to Moodle 2.6.
    1360       *
    1361       * They can still be accessed publicly via magic __call() function with no warnings
    1362       * but are not listed in the class methods list.
    1363       * For the consistency of the code it is better to use corresponding properties.
    1364       *
    1365       * These methods be deprecated completely in later versions.
    1366       *
    1367       * @var array $standardmethods
    1368       */
    1369      private static $standardmethods = array(
    1370          // Following methods are not recommended to use because there have associated read-only properties.
    1371          'get_url',
    1372          'get_content',
    1373          'get_extra_classes',
    1374          'get_on_click',
    1375          'get_custom_data',
    1376          'get_after_link',
    1377          'get_after_edit_icons',
    1378          // Method obtain_dynamic_data() should not be called from outside of this class but it was public before Moodle 2.6.
    1379          'obtain_dynamic_data',
    1380      );
    1381  
    1382      /**
    1383       * Magic method to call functions that are now declared as private but were public in Moodle before 2.6.
    1384       * These private methods can not be used anymore.
    1385       *
    1386       * @param string $name
    1387       * @param array $arguments
    1388       * @return mixed
    1389       * @throws coding_exception
    1390       */
    1391      public function __call($name, $arguments) {
    1392          if (in_array($name, self::$standardmethods)) {
    1393              $message = "cm_info::$name() can not be used anymore.";
    1394              if ($alternative = array_search($name, self::$standardproperties)) {
    1395                  $message .= " Please use the property cm_info->$alternative instead.";
    1396              }
    1397              throw new coding_exception($message);
    1398          }
    1399          throw new coding_exception("Method cm_info::{$name}() does not exist");
    1400      }
    1401  
    1402      /**
    1403       * Magic method getter
    1404       *
    1405       * @param string $name
    1406       * @return mixed
    1407       */
    1408      public function __get($name) {
    1409          if (isset(self::$standardproperties[$name])) {
    1410              if ($method = self::$standardproperties[$name]) {
    1411                  return $this->$method();
    1412              } else {
    1413                  return $this->$name;
    1414              }
    1415          } else {
    1416              debugging('Invalid cm_info property accessed: '.$name);
    1417              return null;
    1418          }
    1419      }
    1420  
    1421      /**
    1422       * Implementation of IteratorAggregate::getIterator(), allows to cycle through properties
    1423       * and use {@link convert_to_array()}
    1424       *
    1425       * @return ArrayIterator
    1426       */
    1427      public function getIterator() {
    1428          // Make sure dynamic properties are retrieved prior to view properties.
    1429          $this->obtain_dynamic_data();
    1430          $ret = array();
    1431  
    1432          // Do not iterate over deprecated properties.
    1433          $props = self::$standardproperties;
    1434          unset($props['groupmembersonly']);
    1435  
    1436          foreach ($props as $key => $unused) {
    1437              $ret[$key] = $this->__get($key);
    1438          }
    1439          return new ArrayIterator($ret);
    1440      }
    1441  
    1442      /**
    1443       * Magic method for function isset()
    1444       *
    1445       * @param string $name
    1446       * @return bool
    1447       */
    1448      public function __isset($name) {
    1449          if (isset(self::$standardproperties[$name])) {
    1450              $value = $this->__get($name);
    1451              return isset($value);
    1452          }
    1453          return false;
    1454      }
    1455  
    1456      /**
    1457       * Magic method for function empty()
    1458       *
    1459       * @param string $name
    1460       * @return bool
    1461       */
    1462      public function __empty($name) {
    1463          if (isset(self::$standardproperties[$name])) {
    1464              $value = $this->__get($name);
    1465              return empty($value);
    1466          }
    1467          return true;
    1468      }
    1469  
    1470      /**
    1471       * Magic method setter
    1472       *
    1473       * Will display the developer warning when trying to set/overwrite property.
    1474       *
    1475       * @param string $name
    1476       * @param mixed $value
    1477       */
    1478      public function __set($name, $value) {
    1479          debugging("It is not allowed to set the property cm_info::\${$name}", DEBUG_DEVELOPER);
    1480      }
    1481  
    1482      /**
    1483       * @return bool True if this module has a 'view' page that should be linked to in navigation
    1484       *   etc (note: modules may still have a view.php file, but return false if this is not
    1485       *   intended to be linked to from 'normal' parts of the interface; this is what label does).
    1486       */
    1487      public function has_view() {
    1488          return !is_null($this->url);
    1489      }
    1490  
    1491      /**
    1492       * Gets the URL to link to for this module.
    1493       *
    1494       * This method is normally called by the property ->url, but can be called directly if
    1495       * there is a case when it might be called recursively (you can't call property values
    1496       * recursively).
    1497       *
    1498       * @return moodle_url URL to link to for this module, or null if it doesn't have a view page
    1499       */
    1500      public function get_url() {
    1501          $this->obtain_dynamic_data();
    1502          return $this->url;
    1503      }
    1504  
    1505      /**
    1506       * Obtains content to display on main (view) page.
    1507       * Note: Will collect view data, if not already obtained.
    1508       * @return string Content to display on main page below link, or empty string if none
    1509       */
    1510      private function get_content() {
    1511          $this->obtain_view_data();
    1512          return $this->content;
    1513      }
    1514  
    1515      /**
    1516       * Returns the content to display on course/overview page, formatted and passed through filters
    1517       *
    1518       * if $options['context'] is not specified, the module context is used
    1519       *
    1520       * @param array|stdClass $options formatting options, see {@link format_text()}
    1521       * @return string
    1522       */
    1523      public function get_formatted_content($options = array()) {
    1524          $this->obtain_view_data();
    1525          if (empty($this->content)) {
    1526              return '';
    1527          }
    1528          if ($this->contentisformatted) {
    1529              return $this->content;
    1530          }
    1531  
    1532          // Improve filter performance by preloading filter setttings for all
    1533          // activities on the course (this does nothing if called multiple
    1534          // times)
    1535          filter_preload_activities($this->get_modinfo());
    1536  
    1537          $options = (array)$options;
    1538          if (!isset($options['context'])) {
    1539              $options['context'] = $this->get_context();
    1540          }
    1541          return format_text($this->content, FORMAT_HTML, $options);
    1542      }
    1543  
    1544      /**
    1545       * Getter method for property $name, ensures that dynamic data is obtained.
    1546       *
    1547       * This method is normally called by the property ->name, but can be called directly if there
    1548       * is a case when it might be called recursively (you can't call property values recursively).
    1549       *
    1550       * @return string
    1551       */
    1552      public function get_name() {
    1553          $this->obtain_dynamic_data();
    1554          return $this->name;
    1555      }
    1556  
    1557      /**
    1558       * Returns the name to display on course/overview page, formatted and passed through filters
    1559       *
    1560       * if $options['context'] is not specified, the module context is used
    1561       *
    1562       * @param array|stdClass $options formatting options, see {@link format_string()}
    1563       * @return string
    1564       */
    1565      public function get_formatted_name($options = array()) {
    1566          global $CFG;
    1567          $options = (array)$options;
    1568          if (!isset($options['context'])) {
    1569              $options['context'] = $this->get_context();
    1570          }
    1571          // Improve filter performance by preloading filter setttings for all
    1572          // activities on the course (this does nothing if called multiple
    1573          // times).
    1574          if (!empty($CFG->filterall)) {
    1575              filter_preload_activities($this->get_modinfo());
    1576          }
    1577          return format_string($this->get_name(), true,  $options);
    1578      }
    1579  
    1580      /**
    1581       * Note: Will collect view data, if not already obtained.
    1582       * @return string Extra CSS classes to add to html output for this activity on main page
    1583       */
    1584      private function get_extra_classes() {
    1585          $this->obtain_view_data();
    1586          return $this->extraclasses;
    1587      }
    1588  
    1589      /**
    1590       * @return string Content of HTML on-click attribute. This string will be used literally
    1591       * as a string so should be pre-escaped.
    1592       */
    1593      private function get_on_click() {
    1594          // Does not need view data; may be used by navigation
    1595          $this->obtain_dynamic_data();
    1596          return $this->onclick;
    1597      }
    1598      /**
    1599       * Getter method for property $customdata, ensures that dynamic data is retrieved.
    1600       *
    1601       * This method is normally called by the property ->customdata, but can be called directly if there
    1602       * is a case when it might be called recursively (you can't call property values recursively).
    1603       *
    1604       * @return mixed Optional custom data stored in modinfo cache for this activity, or null if none
    1605       */
    1606      public function get_custom_data() {
    1607          $this->obtain_dynamic_data();
    1608          return $this->customdata;
    1609      }
    1610  
    1611      /**
    1612       * Note: Will collect view data, if not already obtained.
    1613       * @return string Extra HTML code to display after link
    1614       */
    1615      private function get_after_link() {
    1616          $this->obtain_view_data();
    1617          return $this->afterlink;
    1618      }
    1619  
    1620      /**
    1621       * Note: Will collect view data, if not already obtained.
    1622       * @return string Extra HTML code to display after editing icons (e.g. more icons)
    1623       */
    1624      private function get_after_edit_icons() {
    1625          $this->obtain_view_data();
    1626          return $this->afterediticons;
    1627      }
    1628  
    1629      /**
    1630       * @param moodle_core_renderer $output Output render to use, or null for default (global)
    1631       * @return moodle_url Icon URL for a suitable icon to put beside this cm
    1632       */
    1633      public function get_icon_url($output = null) {
    1634          global $OUTPUT;
    1635          $this->obtain_dynamic_data();
    1636          if (!$output) {
    1637              $output = $OUTPUT;
    1638          }
    1639          // Support modules setting their own, external, icon image
    1640          if (!empty($this->iconurl)) {
    1641              $icon = $this->iconurl;
    1642  
    1643          // Fallback to normal local icon + component procesing
    1644          } else if (!empty($this->icon)) {
    1645              if (substr($this->icon, 0, 4) === 'mod/') {
    1646                  list($modname, $iconname) = explode('/', substr($this->icon, 4), 2);
    1647                  $icon = $output->image_url($iconname, $modname);
    1648              } else {
    1649                  if (!empty($this->iconcomponent)) {
    1650                      // Icon  has specified component
    1651                      $icon = $output->image_url($this->icon, $this->iconcomponent);
    1652                  } else {
    1653                      // Icon does not have specified component, use default
    1654                      $icon = $output->image_url($this->icon);
    1655                  }
    1656              }
    1657          } else {
    1658              $icon = $output->image_url('icon', $this->modname);
    1659          }
    1660          return $icon;
    1661      }
    1662  
    1663      /**
    1664       * @param string $textclasses additionnal classes for grouping label
    1665       * @return string An empty string or HTML grouping label span tag
    1666       */
    1667      public function get_grouping_label($textclasses = '') {
    1668          $groupinglabel = '';
    1669          if ($this->effectivegroupmode != NOGROUPS && !empty($this->groupingid) &&
    1670                  has_capability('moodle/course:managegroups', context_course::instance($this->course))) {
    1671              $groupings = groups_get_all_groupings($this->course);
    1672              $groupinglabel = html_writer::tag('span', '('.format_string($groupings[$this->groupingid]->name).')',
    1673                  array('class' => 'groupinglabel '.$textclasses));
    1674          }
    1675          return $groupinglabel;
    1676      }
    1677  
    1678      /**
    1679       * Returns a localised human-readable name of the module type.
    1680       *
    1681       * @param bool $plural If true, the function returns the plural form of the name.
    1682       * @return lang_string
    1683       */
    1684      public function get_module_type_name($plural = false) {
    1685          $modnames = get_module_types_names($plural);
    1686          if (isset($modnames[$this->modname])) {
    1687              return $modnames[$this->modname];
    1688          } else {
    1689              return null;
    1690          }
    1691      }
    1692  
    1693      /**
    1694       * Returns a localised human-readable name of the module type in plural form - calculated on request
    1695       *
    1696       * @return string
    1697       */
    1698      private function get_module_type_name_plural() {
    1699          return $this->get_module_type_name(true);
    1700      }
    1701  
    1702      /**
    1703       * @return course_modinfo Modinfo object that this came from
    1704       */
    1705      public function get_modinfo() {
    1706          return $this->modinfo;
    1707      }
    1708  
    1709      /**
    1710       * Returns the section this module belongs to
    1711       *
    1712       * @return section_info
    1713       */
    1714      public function get_section_info() {
    1715          return $this->modinfo->get_section_info($this->sectionnum);
    1716      }
    1717  
    1718      /**
    1719       * Returns course object that was used in the first {@link get_fast_modinfo()} call.
    1720       *
    1721       * It may not contain all fields from DB table {course} but always has at least the following:
    1722       * id,shortname,fullname,format,enablecompletion,groupmode,groupmodeforce,cacherev
    1723       *
    1724       * If the course object lacks the field you need you can use the global
    1725       * function {@link get_course()} that will save extra query if you access
    1726       * current course or frontpage course.
    1727       *
    1728       * @return stdClass
    1729       */
    1730      public function get_course() {
    1731          return $this->modinfo->get_course();
    1732      }
    1733  
    1734      /**
    1735       * Returns course id for which the modinfo was generated.
    1736       *
    1737       * @return int
    1738       */
    1739      private function get_course_id() {
    1740          return $this->modinfo->get_course_id();
    1741      }
    1742  
    1743      /**
    1744       * Returns group mode used for the course containing the module
    1745       *
    1746       * @return int one of constants NOGROUPS, SEPARATEGROUPS, VISIBLEGROUPS
    1747       */
    1748      private function get_course_groupmode() {
    1749          return $this->modinfo->get_course()->groupmode;
    1750      }
    1751  
    1752      /**
    1753       * Returns whether group mode is forced for the course containing the module
    1754       *
    1755       * @return bool
    1756       */
    1757      private function get_course_groupmodeforce() {
    1758          return $this->modinfo->get_course()->groupmodeforce;
    1759      }
    1760  
    1761      /**
    1762       * Returns effective groupmode of the module that may be overwritten by forced course groupmode.
    1763       *
    1764       * @return int one of constants NOGROUPS, SEPARATEGROUPS, VISIBLEGROUPS
    1765       */
    1766      private function get_effective_groupmode() {
    1767          $groupmode = $this->groupmode;
    1768          if ($this->modinfo->get_course()->groupmodeforce) {
    1769              $groupmode = $this->modinfo->get_course()->groupmode;
    1770              if ($groupmode != NOGROUPS && !plugin_supports('mod', $this->modname, FEATURE_GROUPS, false)) {
    1771                  $groupmode = NOGROUPS;
    1772              }
    1773          }
    1774          return $groupmode;
    1775      }
    1776  
    1777      /**
    1778       * @return context_module Current module context
    1779       */
    1780      private function get_context() {
    1781          return context_module::instance($this->id);
    1782      }
    1783  
    1784      /**
    1785       * Returns itself in the form of stdClass.
    1786       *
    1787       * The object includes all fields that table course_modules has and additionally
    1788       * fields 'name', 'modname', 'sectionnum' (if requested).
    1789       *
    1790       * This can be used as a faster alternative to {@link get_coursemodule_from_id()}
    1791       *
    1792       * @param bool $additionalfields include additional fields 'name', 'modname', 'sectionnum'
    1793       * @return stdClass
    1794       */
    1795      public function get_course_module_record($additionalfields = false) {
    1796          $cmrecord = new stdClass();
    1797  
    1798          // Standard fields from table course_modules.
    1799          static $cmfields = array('id', 'course', 'module', 'instance', 'section', 'idnumber', 'added',
    1800              'score', 'indent', 'visible', 'visibleoncoursepage', 'visibleold', 'groupmode', 'groupingid',
    1801              'completion', 'completiongradeitemnumber', 'completionview', 'completionexpected',
    1802              'showdescription', 'availability', 'deletioninprogress');
    1803          foreach ($cmfields as $key) {
    1804              $cmrecord->$key = $this->$key;
    1805          }
    1806  
    1807          // Additional fields that function get_coursemodule_from_id() adds.
    1808          if ($additionalfields) {
    1809              $cmrecord->name = $this->name;
    1810              $cmrecord->modname = $this->modname;
    1811              $cmrecord->sectionnum = $this->sectionnum;
    1812          }
    1813  
    1814          return $cmrecord;
    1815      }
    1816  
    1817      // Set functions
    1818      ////////////////
    1819  
    1820      /**
    1821       * Sets content to display on course view page below link (if present).
    1822       * @param string $content New content as HTML string (empty string if none)
    1823       * @param bool $isformatted Whether user content is already passed through format_text/format_string and should not
    1824       *    be formatted again. This can be useful when module adds interactive elements on top of formatted user text.
    1825       * @return void
    1826       */
    1827      public function set_content($content, $isformatted = false) {
    1828          $this->content = $content;
    1829          $this->contentisformatted = $isformatted;
    1830      }
    1831  
    1832      /**
    1833       * Sets extra classes to include in CSS.
    1834       * @param string $extraclasses Extra classes (empty string if none)
    1835       * @return void
    1836       */
    1837      public function set_extra_classes($extraclasses) {
    1838          $this->extraclasses = $extraclasses;
    1839      }
    1840  
    1841      /**
    1842       * Sets the external full url that points to the icon being used
    1843       * by the activity. Useful for external-tool modules (lti...)
    1844       * If set, takes precedence over $icon and $iconcomponent
    1845       *
    1846       * @param moodle_url $iconurl full external url pointing to icon image for activity
    1847       * @return void
    1848       */
    1849      public function set_icon_url(moodle_url $iconurl) {
    1850          $this->iconurl = $iconurl;
    1851      }
    1852  
    1853      /**
    1854       * Sets value of on-click attribute for JavaScript.
    1855       * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
    1856       * @param string $onclick New onclick attribute which should be HTML-escaped
    1857       *   (empty string if none)
    1858       * @return void
    1859       */
    1860      public function set_on_click($onclick) {
    1861          $this->check_not_view_only();
    1862          $this->onclick = $onclick;
    1863      }
    1864  
    1865      /**
    1866       * Overrides the value of an element in the customdata array.
    1867       *
    1868       * @param string $name The key in the customdata array
    1869       * @param mixed $value The value
    1870       */
    1871      public function override_customdata($name, $value) {
    1872          if (!is_array($this->customdata)) {
    1873              $this->customdata = [];
    1874          }
    1875          $this->customdata[$name] = $value;
    1876      }
    1877  
    1878      /**
    1879       * Sets HTML that displays after link on course view page.
    1880       * @param string $afterlink HTML string (empty string if none)
    1881       * @return void
    1882       */
    1883      public function set_after_link($afterlink) {
    1884          $this->afterlink = $afterlink;
    1885      }
    1886  
    1887      /**
    1888       * Sets HTML that displays after edit icons on course view page.
    1889       * @param string $afterediticons HTML string (empty string if none)
    1890       * @return void
    1891       */
    1892      public function set_after_edit_icons($afterediticons) {
    1893          $this->afterediticons = $afterediticons;
    1894      }
    1895  
    1896      /**
    1897       * Changes the name (text of link) for this module instance.
    1898       * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
    1899       * @param string $name Name of activity / link text
    1900       * @return void
    1901       */
    1902      public function set_name($name) {
    1903          if ($this->state < self::STATE_BUILDING_DYNAMIC) {
    1904              $this->update_user_visible();
    1905          }
    1906          $this->name = $name;
    1907      }
    1908  
    1909      /**
    1910       * Turns off the view link for this module instance.
    1911       * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
    1912       * @return void
    1913       */
    1914      public function set_no_view_link() {
    1915          $this->check_not_view_only();
    1916          $this->url = null;
    1917      }
    1918  
    1919      /**
    1920       * Sets the 'uservisible' flag. This can be used (by setting false) to prevent access and
    1921       * display of this module link for the current user.
    1922       * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
    1923       * @param bool $uservisible
    1924       * @return void
    1925       */
    1926      public function set_user_visible($uservisible) {
    1927          $this->check_not_view_only();
    1928          $this->uservisible = $uservisible;
    1929      }
    1930  
    1931      /**
    1932       * Sets the 'available' flag and related details. This flag is normally used to make
    1933       * course modules unavailable until a certain date or condition is met. (When a course
    1934       * module is unavailable, it is still visible to users who have viewhiddenactivities
    1935       * permission.)
    1936       *
    1937       * When this is function is called, user-visible status is recalculated automatically.
    1938       *
    1939       * The $showavailability flag does not really do anything any more, but is retained
    1940       * for backward compatibility. Setting this to false will cause $availableinfo to
    1941       * be ignored.
    1942       *
    1943       * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
    1944       * @param bool $available False if this item is not 'available'
    1945       * @param int $showavailability 0 = do not show this item at all if it's not available,
    1946       *   1 = show this item greyed out with the following message
    1947       * @param string $availableinfo Information about why this is not available, or
    1948       *   empty string if not displaying
    1949       * @return void
    1950       */
    1951      public function set_available($available, $showavailability=0, $availableinfo='') {
    1952          $this->check_not_view_only();
    1953          $this->available = $available;
    1954          if (!$showavailability) {
    1955              $availableinfo = '';
    1956          }
    1957          $this->availableinfo = $availableinfo;
    1958          $this->update_user_visible();
    1959      }
    1960  
    1961      /**
    1962       * Some set functions can only be called from _cm_info_dynamic and not _cm_info_view.
    1963       * This is because they may affect parts of this object which are used on pages other
    1964       * than the view page (e.g. in the navigation block, or when checking access on
    1965       * module pages).
    1966       * @return void
    1967       */
    1968      private function check_not_view_only() {
    1969          if ($this->state >= self::STATE_DYNAMIC) {
    1970              throw new coding_exception('Cannot set this data from _cm_info_view because it may ' .
    1971                      'affect other pages as well as view');
    1972          }
    1973      }
    1974  
    1975      /**
    1976       * Constructor should not be called directly; use {@link get_fast_modinfo()}
    1977       *
    1978       * @param course_modinfo $modinfo Parent object
    1979       * @param stdClass $notused1 Argument not used
    1980       * @param stdClass $mod Module object from the modinfo field of course table
    1981       * @param stdClass $notused2 Argument not used
    1982       */
    1983      public function __construct(course_modinfo $modinfo, $notused1, $mod, $notused2) {
    1984          $this->modinfo = $modinfo;
    1985  
    1986          $this->id               = $mod->cm;
    1987          $this->instance         = $mod->id;
    1988          $this->modname          = $mod->mod;
    1989          $this->idnumber         = isset($mod->idnumber) ? $mod->idnumber : '';
    1990          $this->name             = $mod->name;
    1991          $this->visible          = $mod->visible;
    1992          $this->visibleoncoursepage = $mod->visibleoncoursepage;
    1993          $this->sectionnum       = $mod->section; // Note weirdness with name here
    1994          $this->groupmode        = isset($mod->groupmode) ? $mod->groupmode : 0;
    1995          $this->groupingid       = isset($mod->groupingid) ? $mod->groupingid : 0;
    1996          $this->indent           = isset($mod->indent) ? $mod->indent : 0;
    1997          $this->extra            = isset($mod->extra) ? $mod->extra : '';
    1998          $this->extraclasses     = isset($mod->extraclasses) ? $mod->extraclasses : '';
    1999          // iconurl may be stored as either string or instance of moodle_url.
    2000          $this->iconurl          = isset($mod->iconurl) ? new moodle_url($mod->iconurl) : '';
    2001          $this->onclick          = isset($mod->onclick) ? $mod->onclick : '';
    2002          $this->content          = isset($mod->content) ? $mod->content : '';
    2003          $this->icon             = isset($mod->icon) ? $mod->icon : '';
    2004          $this->iconcomponent    = isset($mod->iconcomponent) ? $mod->iconcomponent : '';
    2005          $this->customdata       = isset($mod->customdata) ? $mod->customdata : '';
    2006          $this->showdescription  = isset($mod->showdescription) ? $mod->showdescription : 0;
    2007          $this->state = self::STATE_BASIC;
    2008  
    2009          $this->section = isset($mod->sectionid) ? $mod->sectionid : 0;
    2010          $this->module = isset($mod->module) ? $mod->module : 0;
    2011          $this->added = isset($mod->added) ? $mod->added : 0;
    2012          $this->score = isset($mod->score) ? $mod->score : 0;
    2013          $this->visibleold = isset($mod->visibleold) ? $mod->visibleold : 0;
    2014          $this->deletioninprogress = isset($mod->deletioninprogress) ? $mod->deletioninprogress : 0;
    2015  
    2016          // Note: it saves effort and database space to always include the
    2017          // availability and completion fields, even if availability or completion
    2018          // are actually disabled
    2019          $this->completion = isset($mod->completion) ? $mod->completion : 0;
    2020          $this->completiongradeitemnumber = isset($mod->completiongradeitemnumber)
    2021                  ? $mod->completiongradeitemnumber : null;
    2022          $this->completionview = isset($mod->completionview)
    2023                  ? $mod->completionview : 0;
    2024          $this->completionexpected = isset($mod->completionexpected)
    2025                  ? $mod->completionexpected : 0;
    2026          $this->availability = isset($mod->availability) ? $mod->availability : null;
    2027          $this->conditionscompletion = isset($mod->conditionscompletion)
    2028                  ? $mod->conditionscompletion : array();
    2029          $this->conditionsgrade = isset($mod->conditionsgrade)
    2030                  ? $mod->conditionsgrade : array();
    2031          $this->conditionsfield = isset($mod->conditionsfield)
    2032                  ? $mod->conditionsfield : array();
    2033  
    2034          static $modviews = array();
    2035          if (!isset($modviews[$this->modname])) {
    2036              $modviews[$this->modname] = !plugin_supports('mod', $this->modname,
    2037                      FEATURE_NO_VIEW_LINK);
    2038          }
    2039          $this->url = $modviews[$this->modname]
    2040                  ? new moodle_url('/mod/' . $this->modname . '/view.php', array('id'=>$this->id))
    2041                  : null;
    2042      }
    2043  
    2044      /**
    2045       * Creates a cm_info object from a database record (also accepts cm_info
    2046       * in which case it is just returned unchanged).
    2047       *
    2048       * @param stdClass|cm_info|null|bool $cm Stdclass or cm_info (or null or false)
    2049       * @param int $userid Optional userid (default to current)
    2050       * @return cm_info|null Object as cm_info, or null if input was null/false
    2051       */
    2052      public static function create($cm, $userid = 0) {
    2053          // Null, false, etc. gets passed through as null.
    2054          if (!$cm) {
    2055              return null;
    2056          }
    2057          // If it is already a cm_info object, just return it.
    2058          if ($cm instanceof cm_info) {
    2059              return $cm;
    2060          }
    2061          // Otherwise load modinfo.
    2062          if (empty($cm->id) || empty($cm->course)) {
    2063              throw new coding_exception('$cm must contain ->id and ->course');
    2064          }
    2065          $modinfo = get_fast_modinfo($cm->course, $userid);
    2066          return $modinfo->get_cm($cm->id);
    2067      }
    2068  
    2069      /**
    2070       * If dynamic data for this course-module is not yet available, gets it.
    2071       *
    2072       * This function is automatically called when requesting any course_modinfo property
    2073       * that can be modified by modules (have a set_xxx method).
    2074       *
    2075       * Dynamic data is data which does not come directly from the cache but is calculated at
    2076       * runtime based on the current user. Primarily this concerns whether the user can access
    2077       * the module or not.
    2078       *
    2079       * As part of this function, the module's _cm_info_dynamic function from its lib.php will
    2080       * be called (if it exists). Make sure that the functions that are called here do not use
    2081       * any getter magic method from cm_info.
    2082       * @return void
    2083       */
    2084      private function obtain_dynamic_data() {
    2085          global $CFG;
    2086          $userid = $this->modinfo->get_user_id();
    2087          if ($this->state >= self::STATE_BUILDING_DYNAMIC || $userid == -1) {
    2088              return;
    2089          }
    2090          $this->state = self::STATE_BUILDING_DYNAMIC;
    2091  
    2092          if (!empty($CFG->enableavailability)) {
    2093              // Get availability information.
    2094              $ci = new \core_availability\info_module($this);
    2095  
    2096              // Note that the modinfo currently available only includes minimal details (basic data)
    2097              // but we know that this function does not need anything more than basic data.
    2098              $this->available = $ci->is_available($this->availableinfo, true,
    2099                      $userid, $this->modinfo);
    2100          } else {
    2101              $this->available = true;
    2102          }
    2103  
    2104          // Check parent section.
    2105          if ($this->available) {
    2106              $parentsection = $this->modinfo->get_section_info($this->sectionnum);
    2107              if (!$parentsection->get_available()) {
    2108                  // Do not store info from section here, as that is already
    2109                  // presented from the section (if appropriate) - just change
    2110                  // the flag
    2111                  $this->available = false;
    2112              }
    2113          }
    2114  
    2115          // Update visible state for current user.
    2116          $this->update_user_visible();
    2117  
    2118          // Let module make dynamic changes at this point
    2119          $this->call_mod_function('cm_info_dynamic');
    2120          $this->state = self::STATE_DYNAMIC;
    2121      }
    2122  
    2123      /**
    2124       * Getter method for property $uservisible, ensures that dynamic data is retrieved.
    2125       *
    2126       * This method is normally called by the property ->uservisible, but can be called directly if
    2127       * there is a case when it might be called recursively (you can't call property values
    2128       * recursively).
    2129       *
    2130       * @return bool
    2131       */
    2132      public function get_user_visible() {
    2133          $this->obtain_dynamic_data();
    2134          return $this->uservisible;
    2135      }
    2136  
    2137      /**
    2138       * Returns whether this module is visible to the current user on course page
    2139       *
    2140       * Activity may be visible on the course page but not available, for example
    2141       * when it is hidden conditionally but the condition information is displayed.
    2142       *
    2143       * @return bool
    2144       */
    2145      public function is_visible_on_course_page() {
    2146          $this->obtain_dynamic_data();
    2147          return $this->uservisibleoncoursepage;
    2148      }
    2149  
    2150      /**
    2151       * Whether this module is available but hidden from course page
    2152       *
    2153       * "Stealth" modules are the ones that are not shown on course page but available by following url.
    2154       * They are normally also displayed in grade reports and other reports.
    2155       * Module will be stealth either if visibleoncoursepage=0 or it is a visible module inside the hidden
    2156       * section.
    2157       *
    2158       * @return bool
    2159       */
    2160      public function is_stealth() {
    2161          return !$this->visibleoncoursepage ||
    2162              ($this->visible && ($section = $this->get_section_info()) && !$section->visible);
    2163      }
    2164  
    2165      /**
    2166       * Getter method for property $available, ensures that dynamic data is retrieved
    2167       * @return bool
    2168       */
    2169      private function get_available() {
    2170          $this->obtain_dynamic_data();
    2171          return $this->available;
    2172      }
    2173  
    2174      /**
    2175       * This method can not be used anymore.
    2176       *
    2177       * @see \core_availability\info_module::filter_user_list()
    2178       * @deprecated Since Moodle 2.8
    2179       */
    2180      private function get_deprecated_group_members_only() {
    2181          throw new coding_exception('$cm->groupmembersonly can not be used anymore. ' .
    2182                  'If used to restrict a list of enrolled users to only those who can ' .
    2183                  'access the module, consider \core_availability\info_module::filter_user_list.');
    2184      }
    2185  
    2186      /**
    2187       * Getter method for property $availableinfo, ensures that dynamic data is retrieved
    2188       *
    2189       * @return string Available info (HTML)
    2190       */
    2191      private function get_available_info() {
    2192          $this->obtain_dynamic_data();
    2193          return $this->availableinfo;
    2194      }
    2195  
    2196      /**
    2197       * Works out whether activity is available to the current user
    2198       *
    2199       * If the activity is unavailable, additional checks are required to determine if its hidden or greyed out
    2200       *
    2201       * @return void
    2202       */
    2203      private function update_user_visible() {
    2204          $userid = $this->modinfo->get_user_id();
    2205          if ($userid == -1) {
    2206              return null;
    2207          }
    2208          $this->uservisible = true;
    2209  
    2210          // If the module is being deleted, set the uservisible state to false and return.
    2211          if ($this->deletioninprogress) {
    2212              $this->uservisible = false;
    2213              return null;
    2214          }
    2215  
    2216          // If the user cannot access the activity set the uservisible flag to false.
    2217          // Additional checks are required to determine whether the activity is entirely hidden or just greyed out.
    2218          if ((!$this->visible && !has_capability('moodle/course:viewhiddenactivities', $this->get_context(), $userid)) ||
    2219                  (!$this->get_available() &&
    2220                  !has_capability('moodle/course:ignoreavailabilityrestrictions', $this->get_context(), $userid))) {
    2221  
    2222              $this->uservisible = false;
    2223          }
    2224  
    2225          // Check group membership.
    2226          if ($this->is_user_access_restricted_by_capability()) {
    2227  
    2228               $this->uservisible = false;
    2229              // Ensure activity is completely hidden from the user.
    2230              $this->availableinfo = '';
    2231          }
    2232  
    2233          $this->uservisibleoncoursepage = $this->uservisible &&
    2234              ($this->visibleoncoursepage ||
    2235                  has_capability('moodle/course:manageactivities', $this->get_context(), $userid) ||
    2236                  has_capability('moodle/course:activityvisibility', $this->get_context(), $userid));
    2237          // Activity that is not available, not hidden from course page and has availability
    2238          // info is actually visible on the course page (with availability info and without a link).
    2239          if (!$this->uservisible && $this->visibleoncoursepage && $this->availableinfo) {
    2240              $this->uservisibleoncoursepage = true;
    2241          }
    2242      }
    2243  
    2244      /**
    2245       * This method has been deprecated and should not be used.
    2246       *
    2247       * @see $uservisible
    2248       * @deprecated Since Moodle 2.8
    2249       */
    2250      public function is_user_access_restricted_by_group() {
    2251          throw new coding_exception('cm_info::is_user_access_restricted_by_group() can not be used any more.' .
    2252              ' Use $cm->uservisible to decide whether the current user can access an activity.');
    2253      }
    2254  
    2255      /**
    2256       * Checks whether mod/...:view capability restricts the current user's access.
    2257       *
    2258       * @return bool True if the user access is restricted.
    2259       */
    2260      public function is_user_access_restricted_by_capability() {
    2261          $userid = $this->modinfo->get_user_id();
    2262          if ($userid == -1) {
    2263              return null;
    2264          }
    2265          $capability = 'mod/' . $this->modname . ':view';
    2266          $capabilityinfo = get_capability_info($capability);
    2267          if (!$capabilityinfo) {
    2268              // Capability does not exist, no one is prevented from seeing the activity.
    2269              return false;
    2270          }
    2271  
    2272          // You are blocked if you don't have the capability.
    2273          return !has_capability($capability, $this->get_context(), $userid);
    2274      }
    2275  
    2276      /**
    2277       * Checks whether the module's conditional access settings mean that the
    2278       * user cannot see the activity at all
    2279       *
    2280       * @deprecated since 2.7 MDL-44070
    2281       */
    2282      public function is_user_access_restricted_by_conditional_access() {
    2283          throw new coding_exception('cm_info::is_user_access_restricted_by_conditional_access() ' .
    2284                  'can not be used any more; this function is not needed (use $cm->uservisible ' .
    2285                  'and $cm->availableinfo to decide whether it should be available ' .
    2286                  'or appear)');
    2287      }
    2288  
    2289      /**
    2290       * Calls a module function (if exists), passing in one parameter: this object.
    2291       * @param string $type Name of function e.g. if this is 'grooblezorb' and the modname is
    2292       *   'forum' then it will try to call 'mod_forum_grooblezorb' or 'forum_grooblezorb'
    2293       * @return void
    2294       */
    2295      private function call_mod_function($type) {
    2296          global $CFG;
    2297          $libfile = $CFG->dirroot . '/mod/' . $this->modname . '/lib.php';
    2298          if (file_exists($libfile)) {
    2299              include_once($libfile);
    2300              $function = 'mod_' . $this->modname . '_' . $type;
    2301              if (function_exists($function)) {
    2302                  $function($this);
    2303              } else {
    2304                  $function = $this->modname . '_' . $type;
    2305                  if (function_exists($function)) {
    2306                      $function($this);
    2307                  }
    2308              }
    2309          }
    2310      }
    2311  
    2312      /**
    2313       * If view data for this course-module is not yet available, obtains it.
    2314       *
    2315       * This function is automatically called if any of the functions (marked) which require
    2316       * view data are called.
    2317       *
    2318       * View data is data which is needed only for displaying the course main page (& any similar
    2319       * functionality on other pages) but is not needed in general. Obtaining view data may have
    2320       * a performance cost.
    2321       *
    2322       * As part of this function, the module's _cm_info_view function from its lib.php will
    2323       * be called (if it exists).
    2324       * @return void
    2325       */
    2326      private function obtain_view_data() {
    2327          if ($this->state >= self::STATE_BUILDING_VIEW || $this->modinfo->get_user_id() == -1) {
    2328              return;
    2329          }
    2330          $this->obtain_dynamic_data();
    2331          $this->state = self::STATE_BUILDING_VIEW;
    2332  
    2333          // Let module make changes at this point
    2334          $this->call_mod_function('cm_info_view');
    2335          $this->state = self::STATE_VIEW;
    2336      }
    2337  }
    2338  
    2339  
    2340  /**
    2341   * Returns reference to full info about modules in course (including visibility).
    2342   * Cached and as fast as possible (0 or 1 db query).
    2343   *
    2344   * use get_fast_modinfo($courseid, 0, true) to reset the static cache for particular course
    2345   * use get_fast_modinfo(0, 0, true) to reset the static cache for all courses
    2346   *
    2347   * use rebuild_course_cache($courseid, true) to reset the application AND static cache
    2348   * for particular course when it's contents has changed
    2349   *
    2350   * @param int|stdClass $courseorid object from DB table 'course' (must have field 'id'
    2351   *     and recommended to have field 'cacherev') or just a course id. Just course id
    2352   *     is enough when calling get_fast_modinfo() for current course or site or when
    2353   *     calling for any other course for the second time.
    2354   * @param int $userid User id to populate 'availble' and 'uservisible' attributes of modules and sections.
    2355   *     Set to 0 for current user (default). Set to -1 to avoid calculation of dynamic user-depended data.
    2356   * @param bool $resetonly whether we want to get modinfo or just reset the cache
    2357   * @return course_modinfo|null Module information for course, or null if resetting
    2358   * @throws moodle_exception when course is not found (nothing is thrown if resetting)
    2359   */
    2360  function get_fast_modinfo($courseorid, $userid = 0, $resetonly = false) {
    2361      // compartibility with syntax prior to 2.4:
    2362      if ($courseorid === 'reset') {
    2363          debugging("Using the string 'reset' as the first argument of get_fast_modinfo() is deprecated. Use get_fast_modinfo(0,0,true) instead.", DEBUG_DEVELOPER);
    2364          $courseorid = 0;
    2365          $resetonly = true;
    2366      }
    2367  
    2368      // Function get_fast_modinfo() can never be called during upgrade unless it is used for clearing cache only.
    2369      if (!$resetonly) {
    2370          upgrade_ensure_not_running();
    2371      }
    2372  
    2373      // Function is called with $reset = true
    2374      if ($resetonly) {
    2375          course_modinfo::clear_instance_cache($courseorid);
    2376          return null;
    2377      }
    2378  
    2379      // Function is called with $reset = false, retrieve modinfo
    2380      return course_modinfo::instance($courseorid, $userid);
    2381  }
    2382  
    2383  /**
    2384   * Efficiently retrieves the $course (stdclass) and $cm (cm_info) objects, given
    2385   * a cmid. If module name is also provided, it will ensure the cm is of that type.
    2386   *
    2387   * Usage:
    2388   * list($course, $cm) = get_course_and_cm_from_cmid($cmid, 'forum');
    2389   *
    2390   * Using this method has a performance advantage because it works by loading
    2391   * modinfo for the course - which will then be cached and it is needed later
    2392   * in most requests. It also guarantees that the $cm object is a cm_info and
    2393   * not a stdclass.
    2394   *
    2395   * The $course object can be supplied if already known and will speed
    2396   * up this function - although it is more efficient to use this function to
    2397   * get the course if you are starting from a cmid.
    2398   *
    2399   * To avoid security problems and obscure bugs, you should always specify
    2400   * $modulename if the cmid value came from user input.
    2401   *
    2402   * By default this obtains information (for example, whether user can access
    2403   * the activity) for current user, but you can specify a userid if required.
    2404   *
    2405   * @param stdClass|int $cmorid Id of course-module, or database object
    2406   * @param string $modulename Optional modulename (improves security)
    2407   * @param stdClass|int $courseorid Optional course object if already loaded
    2408   * @param int $userid Optional userid (default = current)
    2409   * @return array Array with 2 elements $course and $cm
    2410   * @throws moodle_exception If the item doesn't exist or is of wrong module name
    2411   */
    2412  function get_course_and_cm_from_cmid($cmorid, $modulename = '', $courseorid = 0, $userid = 0) {
    2413      global $DB;
    2414      if (is_object($cmorid)) {
    2415          $cmid = $cmorid->id;
    2416          if (isset($cmorid->course)) {
    2417              $courseid = (int)$cmorid->course;
    2418          } else {
    2419              $courseid = 0;
    2420          }
    2421      } else {
    2422          $cmid = (int)$cmorid;
    2423          $courseid = 0;
    2424      }
    2425  
    2426      // Validate module name if supplied.
    2427      if ($modulename && !core_component::is_valid_plugin_name('mod', $modulename)) {
    2428          throw new coding_exception('Invalid modulename parameter');
    2429      }
    2430  
    2431      // Get course from last parameter if supplied.
    2432      $course = null;
    2433      if (is_object($courseorid)) {
    2434          $course = $courseorid;
    2435      } else if ($courseorid) {
    2436          $courseid = (int)$courseorid;
    2437      }
    2438  
    2439      if (!$course) {
    2440          if ($courseid) {
    2441              // If course ID is known, get it using normal function.
    2442              $course = get_course($courseid);
    2443          } else {
    2444              // Get course record in a single query based on cmid.
    2445              $course = $DB->get_record_sql("
    2446                      SELECT c.*
    2447                        FROM {course_modules} cm
    2448                        JOIN {course} c ON c.id = cm.course
    2449                       WHERE cm.id = ?", array($cmid), MUST_EXIST);
    2450          }
    2451      }
    2452  
    2453      // Get cm from get_fast_modinfo.
    2454      $modinfo = get_fast_modinfo($course, $userid);
    2455      $cm = $modinfo->get_cm($cmid);
    2456      if ($modulename && $cm->modname !== $modulename) {
    2457          throw new moodle_exception('invalidcoursemodule', 'error');
    2458      }
    2459      return array($course, $cm);
    2460  }
    2461  
    2462  /**
    2463   * Efficiently retrieves the $course (stdclass) and $cm (cm_info) objects, given
    2464   * an instance id or record and module name.
    2465   *
    2466   * Usage:
    2467   * list($course, $cm) = get_course_and_cm_from_instance($forum, 'forum');
    2468   *
    2469   * Using this method has a performance advantage because it works by loading
    2470   * modinfo for the course - which will then be cached and it is needed later
    2471   * in most requests. It also guarantees that the $cm object is a cm_info and
    2472   * not a stdclass.
    2473   *
    2474   * The $course object can be supplied if already known and will speed
    2475   * up this function - although it is more efficient to use this function to
    2476   * get the course if you are starting from an instance id.
    2477   *
    2478   * By default this obtains information (for example, whether user can access
    2479   * the activity) for current user, but you can specify a userid if required.
    2480   *
    2481   * @param stdclass|int $instanceorid Id of module instance, or database object
    2482   * @param string $modulename Modulename (required)
    2483   * @param stdClass|int $courseorid Optional course object if already loaded
    2484   * @param int $userid Optional userid (default = current)
    2485   * @return array Array with 2 elements $course and $cm
    2486   * @throws moodle_exception If the item doesn't exist or is of wrong module name
    2487   */
    2488  function get_course_and_cm_from_instance($instanceorid, $modulename, $courseorid = 0, $userid = 0) {
    2489      global $DB;
    2490  
    2491      // Get data from parameter.
    2492      if (is_object($instanceorid)) {
    2493          $instanceid = $instanceorid->id;
    2494          if (isset($instanceorid->course)) {
    2495              $courseid = (int)$instanceorid->course;
    2496          } else {
    2497              $courseid = 0;
    2498          }
    2499      } else {
    2500          $instanceid = (int)$instanceorid;
    2501          $courseid = 0;
    2502      }
    2503  
    2504      // Get course from last parameter if supplied.
    2505      $course = null;
    2506      if (is_object($courseorid)) {
    2507          $course = $courseorid;
    2508      } else if ($courseorid) {
    2509          $courseid = (int)$courseorid;
    2510      }
    2511  
    2512      // Validate module name if supplied.
    2513      if (!core_component::is_valid_plugin_name('mod', $modulename)) {
    2514          throw new coding_exception('Invalid modulename parameter');
    2515      }
    2516  
    2517      if (!$course) {
    2518          if ($courseid) {
    2519              // If course ID is known, get it using normal function.
    2520              $course = get_course($courseid);
    2521          } else {
    2522              // Get course record in a single query based on instance id.
    2523              $pagetable = '{' . $modulename . '}';
    2524              $course = $DB->get_record_sql("
    2525                      SELECT c.*
    2526                        FROM $pagetable instance
    2527                        JOIN {course} c ON c.id = instance.course
    2528                       WHERE instance.id = ?", array($instanceid), MUST_EXIST);
    2529          }
    2530      }
    2531  
    2532      // Get cm from get_fast_modinfo.
    2533      $modinfo = get_fast_modinfo($course, $userid);
    2534      $instances = $modinfo->get_instances_of($modulename);
    2535      if (!array_key_exists($instanceid, $instances)) {
    2536          throw new moodle_exception('invalidmoduleid', 'error', $instanceid);
    2537      }
    2538      return array($course, $instances[$instanceid]);
    2539  }
    2540  
    2541  
    2542  /**
    2543   * Rebuilds or resets the cached list of course activities stored in MUC.
    2544   *
    2545   * rebuild_course_cache() must NEVER be called from lib/db/upgrade.php.
    2546   * At the same time course cache may ONLY be cleared using this function in
    2547   * upgrade scripts of plugins.
    2548   *
    2549   * During the bulk operations if it is necessary to reset cache of multiple
    2550   * courses it is enough to call {@link increment_revision_number()} for the
    2551   * table 'course' and field 'cacherev' specifying affected courses in select.
    2552   *
    2553   * Cached course information is stored in MUC core/coursemodinfo and is
    2554   * validated with the DB field {course}.cacherev
    2555   *
    2556   * @global moodle_database $DB
    2557   * @param int $courseid id of course to rebuild, empty means all
    2558   * @param boolean $clearonly only clear the cache, gets rebuild automatically on the fly.
    2559   *     Recommended to set to true to avoid unnecessary multiple rebuilding.
    2560   */
    2561  function rebuild_course_cache($courseid=0, $clearonly=false) {
    2562      global $COURSE, $SITE, $DB, $CFG;
    2563  
    2564      // Function rebuild_course_cache() can not be called during upgrade unless it's clear only.
    2565      if (!$clearonly && !upgrade_ensure_not_running(true)) {
    2566          $clearonly = true;
    2567      }
    2568  
    2569      // Destroy navigation caches
    2570      navigation_cache::destroy_volatile_caches();
    2571  
    2572      if (class_exists('format_base')) {
    2573          // if file containing class is not loaded, there is no cache there anyway
    2574          format_base::reset_course_cache($courseid);
    2575      }
    2576  
    2577      $cachecoursemodinfo = cache::make('core', 'coursemodinfo');
    2578      if (empty($courseid)) {
    2579          // Clearing caches for all courses.
    2580          increment_revision_number('course', 'cacherev', '');
    2581          $cachecoursemodinfo->purge();
    2582          course_modinfo::clear_instance_cache();
    2583          // Update global values too.
    2584          $sitecacherev = $DB->get_field('course', 'cacherev', array('id' => SITEID));
    2585          $SITE->cachrev = $sitecacherev;
    2586          if ($COURSE->id == SITEID) {
    2587              $COURSE->cacherev = $sitecacherev;
    2588          } else {
    2589              $COURSE->cacherev = $DB->get_field('course', 'cacherev', array('id' => $COURSE->id));
    2590          }
    2591      } else {
    2592          // Clearing cache for one course, make sure it is deleted from user request cache as well.
    2593          increment_revision_number('course', 'cacherev', 'id = :id', array('id' => $courseid));
    2594          $cachecoursemodinfo->delete($courseid);
    2595          course_modinfo::clear_instance_cache($courseid);
    2596          // Update global values too.
    2597          if ($courseid == $COURSE->id || $courseid == $SITE->id) {
    2598              $cacherev = $DB->get_field('course', 'cacherev', array('id' => $courseid));
    2599              if ($courseid == $COURSE->id) {
    2600                  $COURSE->cacherev = $cacherev;
    2601              }
    2602              if ($courseid == $SITE->id) {
    2603                  $SITE->cachrev = $cacherev;
    2604              }
    2605          }
    2606      }
    2607  
    2608      if ($clearonly) {
    2609          return;
    2610      }
    2611  
    2612      if ($courseid) {
    2613          $select = array('id'=>$courseid);
    2614      } else {
    2615          $select = array();
    2616          core_php_time_limit::raise();  // this could take a while!   MDL-10954
    2617      }
    2618  
    2619      $rs = $DB->get_recordset("course", $select,'','id,'.join(',', course_modinfo::$cachedfields));
    2620      // Rebuild cache for each course.
    2621      foreach ($rs as $course) {
    2622          course_modinfo::build_course_cache($course);
    2623      }
    2624      $rs->close();
    2625  }
    2626  
    2627  
    2628  /**
    2629   * Class that is the return value for the _get_coursemodule_info module API function.
    2630   *
    2631   * Note: For backward compatibility, you can also return a stdclass object from that function.
    2632   * The difference is that the stdclass object may contain an 'extra' field (deprecated,
    2633   * use extraclasses and onclick instead). The stdclass object may not contain
    2634   * the new fields defined here (content, extraclasses, customdata).
    2635   */
    2636  class cached_cm_info {
    2637      /**
    2638       * Name (text of link) for this activity; Leave unset to accept default name
    2639       * @var string
    2640       */
    2641      public $name;
    2642  
    2643      /**
    2644       * Name of icon for this activity. Normally, this should be used together with $iconcomponent
    2645       * to define the icon, as per image_url function.
    2646       * For backward compatibility, if this value is of the form 'mod/forum/icon' then an icon
    2647       * within that module will be used.
    2648       * @see cm_info::get_icon_url()
    2649       * @see renderer_base::image_url()
    2650       * @var string
    2651       */
    2652      public $icon;
    2653  
    2654      /**
    2655       * Component for icon for this activity, as per image_url; leave blank to use default 'moodle'
    2656       * component
    2657       * @see renderer_base::image_url()
    2658       * @var string
    2659       */
    2660      public $iconcomponent;
    2661  
    2662      /**
    2663       * HTML content to be displayed on the main page below the link (if any) for this course-module
    2664       * @var string
    2665       */
    2666      public $content;
    2667  
    2668      /**
    2669       * Custom data to be stored in modinfo for this activity; useful if there are cases when
    2670       * internal information for this activity type needs to be accessible from elsewhere on the
    2671       * course without making database queries. May be of any type but should be short.
    2672       * @var mixed
    2673       */
    2674      public $customdata;
    2675  
    2676      /**
    2677       * Extra CSS class or classes to be added when this activity is displayed on the main page;
    2678       * space-separated string
    2679       * @var string
    2680       */
    2681      public $extraclasses;
    2682  
    2683      /**
    2684       * External URL image to be used by activity as icon, useful for some external-tool modules
    2685       * like lti. If set, takes precedence over $icon and $iconcomponent
    2686       * @var $moodle_url
    2687       */
    2688      public $iconurl;
    2689  
    2690      /**
    2691       * Content of onclick JavaScript; escaped HTML to be inserted as attribute value
    2692       * @var string
    2693       */
    2694      public $onclick;
    2695  }
    2696  
    2697  
    2698  /**
    2699   * Data about a single section on a course. This contains the fields from the
    2700   * course_sections table, plus additional data when required.
    2701   *
    2702   * @property-read int $id Section ID - from course_sections table
    2703   * @property-read int $course Course ID - from course_sections table
    2704   * @property-read int $section Section number - from course_sections table
    2705   * @property-read string $name Section name if specified - from course_sections table
    2706   * @property-read int $visible Section visibility (1 = visible) - from course_sections table
    2707   * @property-read string $summary Section summary text if specified - from course_sections table
    2708   * @property-read int $summaryformat Section summary text format (FORMAT_xx constant) - from course_sections table
    2709   * @property-read string $availability Availability information as JSON string -
    2710   *    from course_sections table
    2711   * @property-read array $conditionscompletion Availability conditions for this section based on the completion of
    2712   *    course-modules (array from course-module id to required completion state
    2713   *    for that module) - from cached data in sectioncache field
    2714   * @property-read array $conditionsgrade Availability conditions for this section based on course grades (array from
    2715   *    grade item id to object with ->min, ->max fields) - from cached data in
    2716   *    sectioncache field
    2717   * @property-read array $conditionsfield Availability conditions for this section based on user fields
    2718   * @property-read bool $available True if this section is available to the given user i.e. if all availability conditions
    2719   *    are met - obtained dynamically
    2720   * @property-read string $availableinfo If section is not available to some users, this string gives information about
    2721   *    availability which can be displayed to students and/or staff (e.g. 'Available from 3 January 2010')
    2722   *    for display on main page - obtained dynamically
    2723   * @property-read bool $uservisible True if this section is available to the given user (for example, if current user
    2724   *    has viewhiddensections capability, they can access the section even if it is not
    2725   *    visible or not available, so this would be true in that case) - obtained dynamically
    2726   * @property-read string $sequence Comma-separated list of all modules in the section. Note, this field may not exactly
    2727   *    match course_sections.sequence if later has references to non-existing modules or not modules of not available module types.
    2728   * @property-read course_modinfo $modinfo
    2729   */
    2730  class section_info implements IteratorAggregate {
    2731      /**
    2732       * Section ID - from course_sections table
    2733       * @var int
    2734       */
    2735      private $_id;
    2736  
    2737      /**
    2738       * Section number - from course_sections table
    2739       * @var int
    2740       */
    2741      private $_section;
    2742  
    2743      /**
    2744       * Section name if specified - from course_sections table
    2745       * @var string
    2746       */
    2747      private $_name;
    2748  
    2749      /**
    2750       * Section visibility (1 = visible) - from course_sections table
    2751       * @var int
    2752       */
    2753      private $_visible;
    2754  
    2755      /**
    2756       * Section summary text if specified - from course_sections table
    2757       * @var string
    2758       */
    2759      private $_summary;
    2760  
    2761      /**
    2762       * Section summary text format (FORMAT_xx constant) - from course_sections table
    2763       * @var int
    2764       */
    2765      private $_summaryformat;
    2766  
    2767      /**
    2768       * Availability information as JSON string - from course_sections table
    2769       * @var string
    2770       */
    2771      private $_availability;
    2772  
    2773      /**
    2774       * Availability conditions for this section based on the completion of
    2775       * course-modules (array from course-module id to required completion state
    2776       * for that module) - from cached data in sectioncache field
    2777       * @var array
    2778       */
    2779      private $_conditionscompletion;
    2780  
    2781      /**
    2782       * Availability conditions for this section based on course grades (array from
    2783       * grade item id to object with ->min, ->max fields) - from cached data in
    2784       * sectioncache field
    2785       * @var array
    2786       */
    2787      private $_conditionsgrade;
    2788  
    2789      /**
    2790       * Availability conditions for this section based on user fields
    2791       * @var array
    2792       */
    2793      private $_conditionsfield;
    2794  
    2795      /**
    2796       * True if this section is available to students i.e. if all availability conditions
    2797       * are met - obtained dynamically on request, see function {@link section_info::get_available()}
    2798       * @var bool|null
    2799       */
    2800      private $_available;
    2801  
    2802      /**
    2803       * If section is not available to some users, this string gives information about
    2804       * availability which can be displayed to students and/or staff (e.g. 'Available from 3
    2805       * January 2010') for display on main page - obtained dynamically on request, see
    2806       * function {@link section_info::get_availableinfo()}
    2807       * @var string
    2808       */
    2809      private $_availableinfo;
    2810  
    2811      /**
    2812       * True if this section is available to the CURRENT user (for example, if current user
    2813       * has viewhiddensections capability, they can access the section even if it is not
    2814       * visible or not available, so this would be true in that case) - obtained dynamically
    2815       * on request, see function {@link section_info::get_uservisible()}
    2816       * @var bool|null
    2817       */
    2818      private $_uservisible;
    2819  
    2820      /**
    2821       * Default values for sectioncache fields; if a field has this value, it won't
    2822       * be stored in the sectioncache cache, to save space. Checks are done by ===
    2823       * which means values must all be strings.
    2824       * @var array
    2825       */
    2826      private static $sectioncachedefaults = array(
    2827          'name' => null,
    2828          'summary' => '',
    2829          'summaryformat' => '1', // FORMAT_HTML, but must be a string
    2830          'visible' => '1',
    2831          'availability' => null
    2832      );
    2833  
    2834      /**
    2835       * Stores format options that have been cached when building 'coursecache'
    2836       * When the format option is requested we look first if it has been cached
    2837       * @var array
    2838       */
    2839      private $cachedformatoptions = array();
    2840  
    2841      /**
    2842       * Stores the list of all possible section options defined in each used course format.
    2843       * @var array
    2844       */
    2845      static private $sectionformatoptions = array();
    2846  
    2847      /**
    2848       * Stores the modinfo object passed in constructor, may be used when requesting
    2849       * dynamically obtained attributes such as available, availableinfo, uservisible.
    2850       * Also used to retrun information about current course or user.
    2851       * @var course_modinfo
    2852       */
    2853      private $modinfo;
    2854  
    2855      /**
    2856       * Constructs object from database information plus extra required data.
    2857       * @param object $data Array entry from cached sectioncache
    2858       * @param int $number Section number (array key)
    2859       * @param int $notused1 argument not used (informaion is available in $modinfo)
    2860       * @param int $notused2 argument not used (informaion is available in $modinfo)
    2861       * @param course_modinfo $modinfo Owner (needed for checking availability)
    2862       * @param int $notused3 argument not used (informaion is available in $modinfo)
    2863       */
    2864      public function __construct($data, $number, $notused1, $notused2, $modinfo, $notused3) {
    2865          global $CFG;
    2866          require_once($CFG->dirroot.'/course/lib.php');
    2867  
    2868          // Data that is always present
    2869          $this->_id = $data->id;
    2870  
    2871          $defaults = self::$sectioncachedefaults +
    2872                  array('conditionscompletion' => array(),
    2873                      'conditionsgrade' => array(),
    2874                      'conditionsfield' => array());
    2875  
    2876          // Data that may use default values to save cache size
    2877          foreach ($defaults as $field => $value) {
    2878              if (isset($data->{$field})) {
    2879                  $this->{'_'.$field} = $data->{$field};
    2880              } else {
    2881                  $this->{'_'.$field} = $value;
    2882              }
    2883          }
    2884  
    2885          // Other data from constructor arguments.
    2886          $this->_section = $number;
    2887          $this->modinfo = $modinfo;
    2888  
    2889          // Cached course format data.
    2890          $course = $modinfo->get_course();
    2891          if (!isset(self::$sectionformatoptions[$course->format])) {
    2892              // Store list of section format options defined in each used course format.
    2893              // They do not depend on particular course but only on its format.
    2894              self::$sectionformatoptions[$course->format] =
    2895                      course_get_format($course)->section_format_options();
    2896          }
    2897          foreach (self::$sectionformatoptions[$course->format] as $field => $option) {
    2898              if (!empty($option['cache'])) {
    2899                  if (isset($data->{$field})) {
    2900                      $this->cachedformatoptions[$field] = $data->{$field};
    2901                  } else if (array_key_exists('cachedefault', $option)) {
    2902                      $this->cachedformatoptions[$field] = $option['cachedefault'];
    2903                  }
    2904              }
    2905          }
    2906      }
    2907  
    2908      /**
    2909       * Magic method to check if the property is set
    2910       *
    2911       * @param string $name name of the property
    2912       * @return bool
    2913       */
    2914      public function __isset($name) {
    2915          if (method_exists($this, 'get_'.$name) ||
    2916                  property_exists($this, '_'.$name) ||
    2917                  array_key_exists($name, self::$sectionformatoptions[$this->modinfo->get_course()->format])) {
    2918              $value = $this->__get($name);
    2919              return isset($value);
    2920          }
    2921          return false;
    2922      }
    2923  
    2924      /**
    2925       * Magic method to check if the property is empty
    2926       *
    2927       * @param string $name name of the property
    2928       * @return bool
    2929       */
    2930      public function __empty($name) {
    2931          if (method_exists($this, 'get_'.$name) ||
    2932                  property_exists($this, '_'.$name) ||
    2933                  array_key_exists($name, self::$sectionformatoptions[$this->modinfo->get_course()->format])) {
    2934              $value = $this->__get($name);
    2935              return empty($value);
    2936          }
    2937          return true;
    2938      }
    2939  
    2940      /**
    2941       * Magic method to retrieve the property, this is either basic section property
    2942       * or availability information or additional properties added by course format
    2943       *
    2944       * @param string $name name of the property
    2945       * @return bool
    2946       */
    2947      public function __get($name) {
    2948          if (method_exists($this, 'get_'.$name)) {
    2949              return $this->{'get_'.$name}();
    2950          }
    2951          if (property_exists($this, '_'.$name)) {
    2952              return $this->{'_'.$name};
    2953          }
    2954          if (array_key_exists($name, $this->cachedformatoptions)) {
    2955              return $this->cachedformatoptions[$name];
    2956          }
    2957          // precheck if the option is defined in format to avoid unnecessary DB queries in get_format_options()
    2958          if (array_key_exists($name, self::$sectionformatoptions[$this->modinfo->get_course()->format])) {
    2959              $formatoptions = course_get_format($this->modinfo->get_course())->get_format_options($this);
    2960              return $formatoptions[$name];
    2961          }
    2962          debugging('Invalid section_info property accessed! '.$name);
    2963          return null;
    2964      }
    2965  
    2966      /**
    2967       * Finds whether this section is available at the moment for the current user.
    2968       *
    2969       * The value can be accessed publicly as $sectioninfo->available, but can be called directly if there
    2970       * is a case when it might be called recursively (you can't call property values recursively).
    2971       *
    2972       * @return bool
    2973       */
    2974      public function get_available() {
    2975          global $CFG;
    2976          $userid = $this->modinfo->get_user_id();
    2977          if ($this->_available !== null || $userid == -1) {
    2978              // Has already been calculated or does not need calculation.
    2979              return $this->_available;
    2980          }
    2981          $this->_available = true;
    2982          $this->_availableinfo = '';
    2983          if (!empty($CFG->enableavailability)) {
    2984              // Get availability information.
    2985              $ci = new \core_availability\info_section($this);
    2986              $this->_available = $ci->is_available($this->_availableinfo, true,
    2987                      $userid, $this->modinfo);
    2988          }
    2989          // Execute the hook from the course format that may override the available/availableinfo properties.
    2990          $currentavailable = $this->_available;
    2991          course_get_format($this->modinfo->get_course())->
    2992              section_get_available_hook($this, $this->_available, $this->_availableinfo);
    2993          if (!$currentavailable && $this->_available) {
    2994              debugging('section_get_available_hook() can not make unavailable section available', DEBUG_DEVELOPER);
    2995              $this->_available = $currentavailable;
    2996          }
    2997          return $this->_available;
    2998      }
    2999  
    3000      /**
    3001       * Returns the availability text shown next to the section on course page.
    3002       *
    3003       * @return string
    3004       */
    3005      private function get_availableinfo() {
    3006          // Calling get_available() will also fill the availableinfo property
    3007          // (or leave it null if there is no userid).
    3008          $this->get_available();
    3009          return $this->_availableinfo;
    3010      }
    3011  
    3012      /**
    3013       * Implementation of IteratorAggregate::getIterator(), allows to cycle through properties
    3014       * and use {@link convert_to_array()}
    3015       *
    3016       * @return ArrayIterator
    3017       */
    3018      public function getIterator() {
    3019          $ret = array();
    3020          foreach (get_object_vars($this) as $key => $value) {
    3021              if (substr($key, 0, 1) == '_') {
    3022                  if (method_exists($this, 'get'.$key)) {
    3023                      $ret[substr($key, 1)] = $this->{'get'.$key}();
    3024                  } else {
    3025                      $ret[substr($key, 1)] = $this->$key;
    3026                  }
    3027              }
    3028          }
    3029          $ret['sequence'] = $this->get_sequence();
    3030          $ret['course'] = $this->get_course();
    3031          $ret = array_merge($ret, course_get_format($this->modinfo->get_course())->get_format_options($this->_section));
    3032          return new ArrayIterator($ret);
    3033      }
    3034  
    3035      /**
    3036       * Works out whether activity is visible *for current user* - if this is false, they
    3037       * aren't allowed to access it.
    3038       *
    3039       * @return bool
    3040       */
    3041      private function get_uservisible() {
    3042          $userid = $this->modinfo->get_user_id();
    3043          if ($this->_uservisible !== null || $userid == -1) {
    3044              // Has already been calculated or does not need calculation.
    3045              return $this->_uservisible;
    3046          }
    3047          $this->_uservisible = true;
    3048          if (!$this->_visible || !$this->get_available()) {
    3049              $coursecontext = context_course::instance($this->get_course());
    3050              if (!$this->_visible && !has_capability('moodle/course:viewhiddensections', $coursecontext, $userid) ||
    3051                      (!$this->get_available() &&
    3052                      !has_capability('moodle/course:ignoreavailabilityrestrictions', $coursecontext, $userid))) {
    3053  
    3054                  $this->_uservisible = false;
    3055              }
    3056          }
    3057          return $this->_uservisible;
    3058      }
    3059  
    3060      /**
    3061       * Restores the course_sections.sequence value
    3062       *
    3063       * @return string
    3064       */
    3065      private function get_sequence() {
    3066          if (!empty($this->modinfo->sections[$this->_section])) {
    3067              return implode(',', $this->modinfo->sections[$this->_section]);
    3068          } else {
    3069              return '';
    3070          }
    3071      }
    3072  
    3073      /**
    3074       * Returns course ID - from course_sections table
    3075       *
    3076       * @return int
    3077       */
    3078      private function get_course() {
    3079          return $this->modinfo->get_course_id();
    3080      }
    3081  
    3082      /**
    3083       * Modinfo object
    3084       *
    3085       * @return course_modinfo
    3086       */
    3087      private function get_modinfo() {
    3088          return $this->modinfo;
    3089      }
    3090  
    3091      /**
    3092       * Prepares section data for inclusion in sectioncache cache, removing items
    3093       * that are set to defaults, and adding availability data if required.
    3094       *
    3095       * Called by build_section_cache in course_modinfo only; do not use otherwise.
    3096       * @param object $section Raw section data object
    3097       */
    3098      public static function convert_for_section_cache($section) {
    3099          global $CFG;
    3100  
    3101          // Course id stored in course table
    3102          unset($section->course);
    3103          // Section number stored in array key
    3104          unset($section->section);
    3105          // Sequence stored implicity in modinfo $sections array
    3106          unset($section->sequence);
    3107  
    3108          // Remove default data
    3109          foreach (self::$sectioncachedefaults as $field => $value) {
    3110              // Exact compare as strings to avoid problems if some strings are set
    3111              // to "0" etc.
    3112              if (isset($section->{$field}) && $section->{$field} === $value) {
    3113                  unset($section->{$field});
    3114              }
    3115          }
    3116      }
    3117  }