lib/modinfolib.php

   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 class course_modinfo extends stdClass {
  44     // For convenience we store the course object here as it is needed in other parts of code
  45     private $course;
  46     // Array of section data from cache
  47     private $sectioninfo;
  48
  49     // Existing data fields
  50     ///////////////////////
  51
  52     // These are public for backward compatibility. Note: it is not possible to retain BC
  53     // using PHP magic get methods because behaviour is different with regard to empty().
  54
  55     /**
  56      * Course ID
  57      * @var int
  58      * @deprecated For new code, use get_course_id instead.
  59      */
  60     public $courseid;
  61
  62     /**
  63      * User ID
  64      * @var int
  65      * @deprecated For new code, use get_user_id instead.
  66      */
  67     public $userid;
  68
  69     /**
  70      * Array from int (section num, e.g. 0) => array of int (course-module id); this list only
  71      * includes sections that actually contain at least one course-module
  72      * @var array
  73      * @deprecated For new code, use get_sections instead
  74      */
  75     public $sections;
  76
  77     /**
  78      * Array from int (cm id) => cm_info object
  79      * @var array
  80      * @deprecated For new code, use get_cms or get_cm instead.
  81      */
  82     public $cms;
  83
  84     /**
  85      * Array from string (modname) => int (instance id) => cm_info object
  86      * @var array
  87      * @deprecated For new code, use get_instances or get_instances_of instead.
  88      */
  89     public $instances;
  90
  91     /**
  92      * Groups that the current user belongs to. This value is usually not available (set to null)
  93      * unless the course has activities set to groupmembersonly. When set, it is an array of
  94      * grouping id => array of group id => group id. Includes grouping id 0 for 'all groups'.
  95      * @var array
  96      * @deprecated Don't use this! For new code, use get_groups.
  97      */
  98     public $groups;
  99
 100     // Get methods for data
 101     ///////////////////////
 102
 103     /**
 104      * @return object Moodle course object that was used to construct this data
 105      */
 106     public function get_course() {
 107         return $this->course;
 108     }
 109
 110     /**
 111      * @return int Course ID
 112      */
 113     public function get_course_id() {
 114         return $this->courseid;
 115     }
 116
 117     /**
 118      * @return int User ID
 119      */
 120     public function get_user_id() {
 121         return $this->userid;
 122     }
 123
 124     /**
 125      * @return array Array from section number (e.g. 0) to array of course-module IDs in that
 126      *   section; this only includes sections that contain at least one course-module
 127      */
 128     public function get_sections() {
 129         return $this->sections;
 130     }
 131
 132     /**
 133      * @return array Array from course-module instance to cm_info object within this course, in
 134      *   order of appearance
 135      */
 136     public function get_cms() {
 137         return $this->cms;
 138     }
 139
 140     /**
 141      * Obtains a single course-module object (for a course-module that is on this course).
 142      * @param int $cmid Course-module ID
 143      * @return cm_info Information about that course-module
 144      * @throws moodle_exception If the course-module does not exist
 145      */
 146     public function get_cm($cmid) {
 147         if (empty($this->cms[$cmid])) {
 148             throw new moodle_exception('invalidcoursemodule', 'error');
 149         }
 150         return $this->cms[$cmid];
 151     }
 152
 153     /**
 154      * Obtains all module instances on this course.
 155      * @return array Array from module name => array from instance id => cm_info
 156      */
 157     public function get_instances() {
 158         return $this->instances;
 159     }
 160
 161     /**
 162      * Returns array of localised human-readable module names used in this course
 163      *
 164      * @param bool $plural if true returns the plural form of modules names
 165      * @return array
 166      */
 167     public function get_used_module_names($plural = false) {
 168         $modnames = get_module_types_names($plural);
 169         $modnamesused = array();
 170         foreach ($this->get_cms() as $cmid => $mod) {
 171             if (isset($modnames[$mod->modname]) && $mod->uservisible) {
 172                 $modnamesused[$mod->modname] = $modnames[$mod->modname];
 173             }
 174         }
 175         collatorlib::asort($modnamesused);
 176         return $modnamesused;
 177     }
 178
 179     /**
 180      * Obtains all instances of a particular module on this course.
 181      * @param $modname Name of module (not full frankenstyle) e.g. 'label'
 182      * @return array Array from instance id => cm_info for modules on this course; empty if none
 183      */
 184     public function get_instances_of($modname) {
 185         if (empty($this->instances[$modname])) {
 186             return array();
 187         }
 188         return $this->instances[$modname];
 189     }
 190
 191     /**
 192      * Returns groups that the current user belongs to on the course. Note: If not already
 193      * available, this may make a database query.
 194      * @param int $groupingid Grouping ID or 0 (default) for all groups
 195      * @return array Array of int (group id) => int (same group id again); empty array if none
 196      */
 197     public function get_groups($groupingid=0) {
 198         if (is_null($this->groups)) {
 199             // NOTE: Performance could be improved here. The system caches user groups
 200             // in $USER->groupmember[$courseid] => array of groupid=>groupid. Unfortunately this
 201             // structure does not include grouping information. It probably could be changed to
 202             // do so, without a significant performance hit on login, thus saving this one query
 203             // each request.
 204             $this->groups = groups_get_user_groups($this->courseid, $this->userid);
 205         }
 206         if (!isset($this->groups[$groupingid])) {
 207             return array();
 208         }
 209         return $this->groups[$groupingid];
 210     }
 211
 212     /**
 213      * Gets all sections as array from section number => data about section.
 214      * @return array Array of section_info objects organised by section number
 215      */
 216     public function get_section_info_all() {
 217         return $this->sectioninfo;
 218     }
 219
 220     /**
 221      * Gets data about specific numbered section.
 222      * @param int $sectionnumber Number (not id) of section
 223      * @param int $strictness Use MUST_EXIST to throw exception if it doesn't
 224      * @return section_info Information for numbered section or null if not found
 225      */
 226     public function get_section_info($sectionnumber, $strictness = IGNORE_MISSING) {
 227         if (!array_key_exists($sectionnumber, $this->sectioninfo)) {
 228             if ($strictness === MUST_EXIST) {
 229                 throw new moodle_exception('sectionnotexist');
 230             } else {
 231                 return null;
 232             }
 233         }
 234         return $this->sectioninfo[$sectionnumber];
 235     }
 236
 237     /**
 238      * Constructs based on course.
 239      * Note: This constructor should not usually be called directly.
 240      * Use get_fast_modinfo($course) instead as this maintains a cache.
 241      * @param object $course Moodle course object, which may include modinfo
 242      * @param int $userid User ID
 243      */
 244     public function __construct($course, $userid) {
 245         global $CFG, $DB;
 246
 247         // Check modinfo field is set. If not, build and load it.
 248         if (empty($course->modinfo) || empty($course->sectioncache)) {
 249             rebuild_course_cache($course->id);
 250             $course = $DB->get_record('course', array('id'=>$course->id), '*', MUST_EXIST);
 251         }
 252
 253         // Set initial values
 254         $this->courseid = $course->id;
 255         $this->userid = $userid;
 256         $this->sections = array();
 257         $this->cms = array();
 258         $this->instances = array();
 259         $this->groups = null;
 260         $this->course = $course;
 261
 262         // Load modinfo field into memory as PHP object and check it's valid
 263         $info = unserialize($course->modinfo);
 264         if (!is_array($info)) {
 265             // hmm, something is wrong - lets try to fix it
 266             rebuild_course_cache($course->id);
 267             $course->modinfo = $DB->get_field('course', 'modinfo', array('id'=>$course->id));
 268             $info = unserialize($course->modinfo);
 269             if (!is_array($info)) {
 270                 // If it still fails, abort
 271                 debugging('Problem with "modinfo" data for this course');
 272                 return;
 273             }
 274         }
 275
 276         // Load sectioncache field into memory as PHP object and check it's valid
 277         $sectioncache = unserialize($course->sectioncache);
 278         if (!is_array($sectioncache) || empty($sectioncache)) {
 279             // hmm, something is wrong - let's fix it
 280             rebuild_course_cache($course->id);
 281             $course->sectioncache = $DB->get_field('course', 'sectioncache', array('id'=>$course->id));
 282             $sectioncache = unserialize($course->sectioncache);
 283             if (!is_array($sectioncache)) {
 284                 // If it still fails, abort
 285                 debugging('Problem with "sectioncache" data for this course');
 286                 return;
 287             }
 288         }
 289
 290         // If we haven't already preloaded contexts for the course, do it now
 291         preload_course_contexts($course->id);
 292
 293         // Loop through each piece of module data, constructing it
 294         $modexists = array();
 295         foreach ($info as $mod) {
 296             if (empty($mod->name)) {
 297                 // something is wrong here
 298                 continue;
 299             }
 300
 301             // Skip modules which don't exist
 302             if (empty($modexists[$mod->mod])) {
 303                 if (!file_exists("$CFG->dirroot/mod/$mod->mod/lib.php")) {
 304                     continue;
 305                 }
 306                 $modexists[$mod->mod] = true;
 307             }
 308
 309             // Construct info for this module
 310             $cm = new cm_info($this, $course, $mod, $info);
 311
 312             // Store module in instances and cms array
 313             if (!isset($this->instances[$cm->modname])) {
 314                 $this->instances[$cm->modname] = array();
 315             }
 316             $this->instances[$cm->modname][$cm->instance] = $cm;
 317             $this->cms[$cm->id] = $cm;
 318
 319             // Reconstruct sections. This works because modules are stored in order
 320             if (!isset($this->sections[$cm->sectionnum])) {
 321                 $this->sections[$cm->sectionnum] = array();
 322             }
 323             $this->sections[$cm->sectionnum][] = $cm->id;
 324         }
 325
 326         // Expand section objects
 327         $this->sectioninfo = array();
 328         foreach ($sectioncache as $number => $data) {
 329             // Calculate sequence
 330             if (isset($this->sections[$number])) {
 331                 $sequence = implode(',', $this->sections[$number]);
 332             } else {
 333                 $sequence = '';
 334             }
 335             // Expand
 336             $this->sectioninfo[$number] = new section_info($data, $number, $course->id, $sequence,
 337                     $this, $userid);
 338         }
 339
 340         // We need at least 'dynamic' data from each course-module (this is basically the remaining
 341         // data which was always present in previous version of get_fast_modinfo, so it's required
 342         // for BC). Creating it in a second pass is necessary because obtain_dynamic_data sometimes
 343         // needs to be able to refer to a 'complete' (with basic data) modinfo.
 344         foreach ($this->cms as $cm) {
 345             $cm->obtain_dynamic_data();
 346         }
 347     }
 348
 349     /**
 350      * Builds a list of information about sections on a course to be stored in
 351      * the course cache. (Does not include information that is already cached
 352      * in some other way.)
 353      *
 354      * Used internally by rebuild_course_cache function; do not use otherwise.
 355      * @param int $courseid Course ID
 356      * @return array Information about sections, indexed by section number (not id)
 357      */
 358     public static function build_section_cache($courseid) {
 359         global $DB;
 360
 361         // Get section data
 362         $sections = $DB->get_records('course_sections', array('course' => $courseid), 'section',
 363                 'section, id, course, name, summary, summaryformat, sequence, visible, ' .
 364                 'availablefrom, availableuntil, showavailability, groupingid');
 365         $compressedsections = array();
 366
 367         $formatoptionsdef = course_get_format($courseid)->section_format_options();
 368         // Remove unnecessary data and add availability
 369         foreach ($sections as $number => $section) {
 370             // Add cached options from course format to $section object
 371             foreach ($formatoptionsdef as $key => $option) {
 372                 if (!empty($option['cache'])) {
 373                     $formatoptions = course_get_format($courseid)->get_format_options($section);
 374                     if (!array_key_exists('cachedefault', $option) || $option['cachedefault'] !== $formatoptions[$key]) {
 375                         $section->$key = $formatoptions[$key];
 376                     }
 377                 }
 378             }
 379             // Clone just in case it is reused elsewhere
 380             $compressedsections[$number] = clone($section);
 381             section_info::convert_for_section_cache($compressedsections[$number]);
 382         }
 383
 384         return $compressedsections;
 385     }
 386 }
 387
 388
 389 /**
 390  * Data about a single module on a course. This contains most of the fields in the course_modules
 391  * table, plus additional data when required.
 392  *
 393  * This object has many public fields; code should treat all these fields as read-only and set
 394  * data only using the supplied set functions. Setting the fields directly is not supported
 395  * and may cause problems later.
 396  */
 397 class cm_info extends stdClass {
 398     /**
 399      * State: Only basic data from modinfo cache is available.
 400      */
 401     const STATE_BASIC = 0;
 402
 403     /**
 404      * State: Dynamic data is available too.
 405      */
 406     const STATE_DYNAMIC = 1;
 407
 408     /**
 409      * State: View data (for course page) is available.
 410      */
 411     const STATE_VIEW = 2;
 412
 413     /**
 414      * Parent object
 415      * @var course_modinfo
 416      */
 417     private $modinfo;
 418
 419     /**
 420      * Level of information stored inside this object (STATE_xx constant)
 421      * @var int
 422      */
 423     private $state;
 424
 425     // Existing data fields
 426     ///////////////////////
 427
 428     /**
 429      * Course-module ID - from course_modules table
 430      * @var int
 431      */
 432     public $id;
 433
 434     /**
 435      * Module instance (ID within module table) - from course_modules table
 436      * @var int
 437      */
 438     public $instance;
 439
 440     /**
 441      * Course ID - from course_modules table
 442      * @var int
 443      */
 444     public $course;
 445
 446     /**
 447      * 'ID number' from course-modules table (arbitrary text set by user) - from
 448      * course_modules table
 449      * @var string
 450      */
 451     public $idnumber;
 452
 453     /**
 454      * Time that this course-module was added (unix time) - from course_modules table
 455      * @var int
 456      */
 457     public $added;
 458
 459     /**
 460      * This variable is not used and is included here only so it can be documented.
 461      * Once the database entry is removed from course_modules, it should be deleted
 462      * here too.
 463      * @var int
 464      * @deprecated Do not use this variable
 465      */
 466     public $score;
 467
 468     /**
 469      * Visible setting (0 or 1; if this is 0, students cannot see/access the activity) - from
 470      * course_modules table
 471      * @var int
 472      */
 473     public $visible;
 474
 475     /**
 476      * Old visible setting (if the entire section is hidden, the previous value for
 477      * visible is stored in this field) - from course_modules table
 478      * @var int
 479      */
 480     public $visibleold;
 481
 482     /**
 483      * Group mode (one of the constants NONE, SEPARATEGROUPS, or VISIBLEGROUPS) - from
 484      * course_modules table
 485      * @var int
 486      */
 487     public $groupmode;
 488
 489     /**
 490      * Grouping ID (0 = all groupings)
 491      * @var int
 492      */
 493     public $groupingid;
 494
 495     /**
 496      * Group members only (if set to 1, only members of a suitable group see this link on the
 497      * course page; 0 = everyone sees it even if they don't belong to a suitable group)  - from
 498      * course_modules table
 499      * @var int
 500      */
 501     public $groupmembersonly;
 502
 503     /**
 504      * Indent level on course page (0 = no indent) - from course_modules table
 505      * @var int
 506      */
 507     public $indent;
 508
 509     /**
 510      * Activity completion setting for this activity, COMPLETION_TRACKING_xx constant - from
 511      * course_modules table
 512      * @var int
 513      */
 514     public $completion;
 515
 516     /**
 517      * Set to the item number (usually 0) if completion depends on a particular
 518      * grade of this activity, or null if completion does not depend on a grade - from
 519      * course_modules table
 520      * @var mixed
 521      */
 522     public $completiongradeitemnumber;
 523
 524     /**
 525      * 1 if 'on view' completion is enabled, 0 otherwise - from course_modules table
 526      * @var int
 527      */
 528     public $completionview;
 529
 530     /**
 531      * Set to a unix time if completion of this activity is expected at a
 532      * particular time, 0 if no time set - from course_modules table
 533      * @var int
 534      */
 535     public $completionexpected;
 536
 537     /**
 538      * Available date for this activity (0 if not set, or set to seconds since epoch; before this
 539      * date, activity does not display to students) - from course_modules table
 540      * @var int
 541      */
 542     public $availablefrom;
 543
 544     /**
 545      * Available until date for this activity (0 if not set, or set to seconds since epoch; from
 546      * this date, activity does not display to students) - from course_modules table
 547      * @var int
 548      */
 549     public $availableuntil;
 550
 551     /**
 552      * When activity is unavailable, this field controls whether it is shown to students (0 =
 553      * hide completely, 1 = show greyed out with information about when it will be available) -
 554      * from course_modules table
 555      * @var int
 556      */
 557     public $showavailability;
 558
 559     /**
 560      * Controls whether the description of the activity displays on the course main page (in
 561      * addition to anywhere it might display within the activity itself). 0 = do not show
 562      * on main page, 1 = show on main page.
 563      * @var int
 564      */
 565     public $showdescription;
 566
 567     /**
 568      * Extra HTML that is put in an unhelpful part of the HTML when displaying this module in
 569      * course page - from cached data in modinfo field
 570      * @deprecated This is crazy, don't use it. Replaced by ->extraclasses and ->onclick
 571      * @var string
 572      */
 573     public $extra;
 574
 575     /**
 576      * Name of icon to use - from cached data in modinfo field
 577      * @var string
 578      */
 579     public $icon;
 580
 581     /**
 582      * Component that contains icon - from cached data in modinfo field
 583      * @var string
 584      */
 585     public $iconcomponent;
 586
 587     /**
 588      * Name of module e.g. 'forum' (this is the same name as the module's main database
 589      * table) - from cached data in modinfo field
 590      * @var string
 591      */
 592     public $modname;
 593
 594     /**
 595      * ID of module - from course_modules table
 596      * @var int
 597      */
 598     public $module;
 599
 600     /**
 601      * Name of module instance for display on page e.g. 'General discussion forum' - from cached
 602      * data in modinfo field
 603      * @var string
 604      */
 605     public $name;
 606
 607     /**
 608      * Section number that this course-module is in (section 0 = above the calendar, section 1
 609      * = week/topic 1, etc) - from cached data in modinfo field
 610      * @var string
 611      */
 612     public $sectionnum;
 613
 614     /**
 615      * Section id - from course_modules table
 616      * @var int
 617      */
 618     public $section;
 619
 620     /**
 621      * Availability conditions for this course-module based on the completion of other
 622      * course-modules (array from other course-module id to required completion state for that
 623      * module) - from cached data in modinfo field
 624      * @var array
 625      */
 626     public $conditionscompletion;
 627
 628     /**
 629      * Availability conditions for this course-module based on course grades (array from
 630      * grade item id to object with ->min, ->max fields) - from cached data in modinfo field
 631      * @var array
 632      */
 633     public $conditionsgrade;
 634
 635     /**
 636      * Availability conditions for this course-module based on user fields
 637      * @var array
 638      */
 639     public $conditionsfield;
 640
 641     /**
 642      * True if this course-module is available to students i.e. if all availability conditions
 643      * are met - obtained dynamically
 644      * @var bool
 645      */
 646     public $available;
 647
 648     /**
 649      * If course-module is not available to students, this string gives information about
 650      * availability which can be displayed to students and/or staff (e.g. 'Available from 3
 651      * January 2010') for display on main page - obtained dynamically
 652      * @var string
 653      */
 654     public $availableinfo;
 655
 656     /**
 657      * True if this course-module is available to the CURRENT user (for example, if current user
 658      * has viewhiddenactivities capability, they can access the course-module even if it is not
 659      * visible or not available, so this would be true in that case)
 660      * @var bool
 661      */
 662     public $uservisible;
 663
 664     /**
 665      * Module context - hacky shortcut
 666      * @deprecated
 667      * @var stdClass
 668      */
 669     public $context;
 670
 671
 672     // New data available only via functions
 673     ////////////////////////////////////////
 674
 675     /**
 676      * @var moodle_url
 677      */
 678     private $url;
 679
 680     /**
 681      * @var string
 682      */
 683     private $content;
 684
 685     /**
 686      * @var string
 687      */
 688     private $extraclasses;
 689
 690     /**
 691      * @var moodle_url full external url pointing to icon image for activity
 692      */
 693     private $iconurl;
 694
 695     /**
 696      * @var string
 697      */
 698     private $onclick;
 699
 700     /**
 701      * @var mixed
 702      */
 703     private $customdata;
 704
 705     /**
 706      * @var string
 707      */
 708     private $afterlink;
 709
 710     /**
 711      * @var string
 712      */
 713     private $afterediticons;
 714
 715     /**
 716      * Magic method getter
 717      *
 718      * @param string $name
 719      * @return mixed
 720      */
 721     public function __get($name) {
 722         switch ($name) {
 723             case 'modplural':
 724                 return $this->get_module_type_name(true);
 725             case 'modfullname':
 726                 return $this->get_module_type_name();
 727             default:
 728                 debugging('Invalid cm_info property accessed: '.$name);
 729                 return null;
 730         }
 731     }
 732
 733     /**
 734      * @return bool True if this module has a 'view' page that should be linked to in navigation
 735      *   etc (note: modules may still have a view.php file, but return false if this is not
 736      *   intended to be linked to from 'normal' parts of the interface; this is what label does).
 737      */
 738     public function has_view() {
 739         return !is_null($this->url);
 740     }
 741
 742     /**
 743      * @return moodle_url URL to link to for this module, or null if it doesn't have a view page
 744      */
 745     public function get_url() {
 746         return $this->url;
 747     }
 748
 749     /**
 750      * Obtains content to display on main (view) page.
 751      * Note: Will collect view data, if not already obtained.
 752      * @return string Content to display on main page below link, or empty string if none
 753      */
 754     public function get_content() {
 755         $this->obtain_view_data();
 756         return $this->content;
 757     }
 758
 759     /**
 760      * Note: Will collect view data, if not already obtained.
 761      * @return string Extra CSS classes to add to html output for this activity on main page
 762      */
 763     public function get_extra_classes() {
 764         $this->obtain_view_data();
 765         return $this->extraclasses;
 766     }
 767
 768     /**
 769      * @return string Content of HTML on-click attribute. This string will be used literally
 770      * as a string so should be pre-escaped.
 771      */
 772     public function get_on_click() {
 773         // Does not need view data; may be used by navigation
 774         return $this->onclick;
 775     }
 776     /**
 777      * @return mixed Optional custom data stored in modinfo cache for this activity, or null if none
 778      */
 779     public function get_custom_data() {
 780         return $this->customdata;
 781     }
 782
 783     /**
 784      * Note: Will collect view data, if not already obtained.
 785      * @return string Extra HTML code to display after link
 786      */
 787     public function get_after_link() {
 788         $this->obtain_view_data();
 789         return $this->afterlink;
 790     }
 791
 792     /**
 793      * Note: Will collect view data, if not already obtained.
 794      * @return string Extra HTML code to display after editing icons (e.g. more icons)
 795      */
 796     public function get_after_edit_icons() {
 797         $this->obtain_view_data();
 798         return $this->afterediticons;
 799     }
 800
 801     /**
 802      * @param moodle_core_renderer $output Output render to use, or null for default (global)
 803      * @return moodle_url Icon URL for a suitable icon to put beside this cm
 804      */
 805     public function get_icon_url($output = null) {
 806         global $OUTPUT;
 807         if (!$output) {
 808             $output = $OUTPUT;
 809         }
 810         // Support modules setting their own, external, icon image
 811         if (!empty($this->iconurl)) {
 812             $icon = $this->iconurl;
 813
 814         // Fallback to normal local icon + component procesing
 815         } else if (!empty($this->icon)) {
 816             if (substr($this->icon, 0, 4) === 'mod/') {
 817                 list($modname, $iconname) = explode('/', substr($this->icon, 4), 2);
 818                 $icon = $output->pix_url($iconname, $modname);
 819             } else {
 820                 if (!empty($this->iconcomponent)) {
 821                     // Icon  has specified component
 822                     $icon = $output->pix_url($this->icon, $this->iconcomponent);
 823                 } else {
 824                     // Icon does not have specified component, use default
 825                     $icon = $output->pix_url($this->icon);
 826                 }
 827             }
 828         } else {
 829             $icon = $output->pix_url('icon', $this->modname);
 830         }
 831         return $icon;
 832     }
 833
 834     /**
 835      * Returns a localised human-readable name of the module type
 836      *
 837      * @param bool $plural return plural form
 838      * @return string
 839      */
 840     public function get_module_type_name($plural = false) {
 841         $modnames = get_module_types_names($plural);
 842         if (isset($modnames[$this->modname])) {
 843             return $modnames[$this->modname];
 844         } else {
 845             return null;
 846         }
 847     }
 848
 849     /**
 850      * @return course_modinfo Modinfo object that this came from
 851      */
 852     public function get_modinfo() {
 853         return $this->modinfo;
 854     }
 855
 856     /**
 857      * @return object Moodle course object that was used to construct this data
 858      */
 859     public function get_course() {
 860         return $this->modinfo->get_course();
 861     }
 862
 863     // Set functions
 864     ////////////////
 865
 866     /**
 867      * Sets content to display on course view page below link (if present).
 868      * @param string $content New content as HTML string (empty string if none)
 869      * @return void
 870      */
 871     public function set_content($content) {
 872         $this->content = $content;
 873     }
 874
 875     /**
 876      * Sets extra classes to include in CSS.
 877      * @param string $extraclasses Extra classes (empty string if none)
 878      * @return void
 879      */
 880     public function set_extra_classes($extraclasses) {
 881         $this->extraclasses = $extraclasses;
 882     }
 883
 884     /**
 885      * Sets the external full url that points to the icon being used
 886      * by the activity. Useful for external-tool modules (lti...)
 887      * If set, takes precedence over $icon and $iconcomponent
 888      *
 889      * @param moodle_url $iconurl full external url pointing to icon image for activity
 890      * @return void
 891      */
 892     public function set_icon_url(moodle_url $iconurl) {
 893         $this->iconurl = $iconurl;
 894     }
 895
 896     /**
 897      * Sets value of on-click attribute for JavaScript.
 898      * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
 899      * @param string $onclick New onclick attribute which should be HTML-escaped
 900      *   (empty string if none)
 901      * @return void
 902      */
 903     public function set_on_click($onclick) {
 904         $this->check_not_view_only();
 905         $this->onclick = $onclick;
 906     }
 907
 908     /**
 909      * Sets HTML that displays after link on course view page.
 910      * @param string $afterlink HTML string (empty string if none)
 911      * @return void
 912      */
 913     public function set_after_link($afterlink) {
 914         $this->afterlink = $afterlink;
 915     }
 916
 917     /**
 918      * Sets HTML that displays after edit icons on course view page.
 919      * @param string $afterediticons HTML string (empty string if none)
 920      * @return void
 921      */
 922     public function set_after_edit_icons($afterediticons) {
 923         $this->afterediticons = $afterediticons;
 924     }
 925
 926     /**
 927      * Changes the name (text of link) for this module instance.
 928      * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
 929      * @param string $name Name of activity / link text
 930      * @return void
 931      */
 932     public function set_name($name) {
 933         $this->update_user_visible();
 934         $this->name = $name;
 935     }
 936
 937     /**
 938      * Turns off the view link for this module instance.
 939      * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
 940      * @return void
 941      */
 942     public function set_no_view_link() {
 943         $this->check_not_view_only();
 944         $this->url = null;
 945     }
 946
 947     /**
 948      * Sets the 'uservisible' flag. This can be used (by setting false) to prevent access and
 949      * display of this module link for the current user.
 950      * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
 951      * @param bool $uservisible
 952      * @return void
 953      */
 954     public function set_user_visible($uservisible) {
 955         $this->check_not_view_only();
 956         $this->uservisible = $uservisible;
 957     }
 958
 959     /**
 960      * Sets the 'available' flag and related details. This flag is normally used to make
 961      * course modules unavailable until a certain date or condition is met. (When a course
 962      * module is unavailable, it is still visible to users who have viewhiddenactivities
 963      * permission.)
 964      *
 965      * When this is function is called, user-visible status is recalculated automatically.
 966      *
 967      * Note: May not be called from _cm_info_view (only _cm_info_dynamic).
 968      * @param bool $available False if this item is not 'available'
 969      * @param int $showavailability 0 = do not show this item at all if it's not available,
 970      *   1 = show this item greyed out with the following message
 971      * @param string $availableinfo Information about why this is not available which displays
 972      *   to those who have viewhiddenactivities, and to everyone if showavailability is set;
 973      *   note that this function replaces the existing data (if any)
 974      * @return void
 975      */
 976     public function set_available($available, $showavailability=0, $availableinfo='') {
 977         $this->check_not_view_only();
 978         $this->available = $available;
 979         $this->showavailability = $showavailability;
 980         $this->availableinfo = $availableinfo;
 981         $this->update_user_visible();
 982     }
 983
 984     /**
 985      * Some set functions can only be called from _cm_info_dynamic and not _cm_info_view.
 986      * This is because they may affect parts of this object which are used on pages other
 987      * than the view page (e.g. in the navigation block, or when checking access on
 988      * module pages).
 989      * @return void
 990      */
 991     private function check_not_view_only() {
 992         if ($this->state >= self::STATE_DYNAMIC) {
 993             throw new coding_exception('Cannot set this data from _cm_info_view because it may ' .
 994                     'affect other pages as well as view');
 995         }
 996     }
 997
 998     /**
 999      * Constructor should not be called directly; use get_fast_modinfo.
1000      * @param course_modinfo $modinfo Parent object
1001      * @param object $course Course row
1002      * @param object $mod Module object from the modinfo field of course table
1003      * @param object $info Entire object from modinfo field of course table
1004      */
1005     public function __construct(course_modinfo $modinfo, $course, $mod, $info) {
1006         global $CFG;
1007         $this->modinfo = $modinfo;
1008
1009         $this->id               = $mod->cm;
1010         $this->instance         = $mod->id;
1011         $this->course           = $course->id;
1012         $this->modname          = $mod->mod;
1013         $this->idnumber         = isset($mod->idnumber) ? $mod->idnumber : '';
1014         $this->name             = $mod->name;
1015         $this->visible          = $mod->visible;
1016         $this->sectionnum       = $mod->section; // Note weirdness with name here
1017         $this->groupmode        = isset($mod->groupmode) ? $mod->groupmode : 0;
1018         $this->groupingid       = isset($mod->groupingid) ? $mod->groupingid : 0;
1019         $this->groupmembersonly = isset($mod->groupmembersonly) ? $mod->groupmembersonly : 0;
1020         $this->indent           = isset($mod->indent) ? $mod->indent : 0;
1021         $this->extra            = isset($mod->extra) ? $mod->extra : '';
1022         $this->extraclasses     = isset($mod->extraclasses) ? $mod->extraclasses : '';
1023         $this->iconurl          = isset($mod->iconurl) ? $mod->iconurl : '';
1024         $this->onclick          = isset($mod->onclick) ? $mod->onclick : '';
1025         $this->content          = isset($mod->content) ? $mod->content : '';
1026         $this->icon             = isset($mod->icon) ? $mod->icon : '';
1027         $this->iconcomponent    = isset($mod->iconcomponent) ? $mod->iconcomponent : '';
1028         $this->customdata       = isset($mod->customdata) ? $mod->customdata : '';
1029         $this->context          = context_module::instance($mod->cm);
1030         $this->showdescription  = isset($mod->showdescription) ? $mod->showdescription : 0;
1031         $this->state = self::STATE_BASIC;
1032
1033         // This special case handles old label data. Labels used to use the 'name' field for
1034         // content
1035         if ($this->modname === 'label' && $this->content === '') {
1036             $this->content = $this->extra;
1037             $this->extra = '';
1038         }
1039
1040         // Note: These fields from $cm were not present in cm_info in Moodle
1041         // 2.0.2 and prior. They may not be available if course cache hasn't
1042         // been rebuilt since then.
1043         $this->section = isset($mod->sectionid) ? $mod->sectionid : 0;
1044         $this->module = isset($mod->module) ? $mod->module : 0;
1045         $this->added = isset($mod->added) ? $mod->added : 0;
1046         $this->score = isset($mod->score) ? $mod->score : 0;
1047         $this->visibleold = isset($mod->visibleold) ? $mod->visibleold : 0;
1048
1049         // Note: it saves effort and database space to always include the
1050         // availability and completion fields, even if availability or completion
1051         // are actually disabled
1052         $this->completion = isset($mod->completion) ? $mod->completion : 0;
1053         $this->completiongradeitemnumber = isset($mod->completiongradeitemnumber)
1054                 ? $mod->completiongradeitemnumber : null;
1055         $this->completionview = isset($mod->completionview)
1056                 ? $mod->completionview : 0;
1057         $this->completionexpected = isset($mod->completionexpected)
1058                 ? $mod->completionexpected : 0;
1059         $this->showavailability = isset($mod->showavailability) ? $mod->showavailability : 0;
1060         $this->availablefrom = isset($mod->availablefrom) ? $mod->availablefrom : 0;
1061         $this->availableuntil = isset($mod->availableuntil) ? $mod->availableuntil : 0;
1062         $this->conditionscompletion = isset($mod->conditionscompletion)
1063                 ? $mod->conditionscompletion : array();
1064         $this->conditionsgrade = isset($mod->conditionsgrade)
1065                 ? $mod->conditionsgrade : array();
1066         $this->conditionsfield = isset($mod->conditionsfield)
1067                 ? $mod->conditionsfield : array();
1068
1069         static $modviews;
1070         if (!isset($modviews[$this->modname])) {
1071             $modviews[$this->modname] = !plugin_supports('mod', $this->modname,
1072                     FEATURE_NO_VIEW_LINK);
1073         }
1074         $this->url = $modviews[$this->modname]
1075                 ? new moodle_url('/mod/' . $this->modname . '/view.php', array('id'=>$this->id))
1076                 : null;
1077     }
1078
1079     /**
1080      * If dynamic data for this course-module is not yet available, gets it.
1081      *
1082      * This function is automatically called when constructing course_modinfo, so users don't
1083      * need to call it.
1084      *
1085      * Dynamic data is data which does not come directly from the cache but is calculated at
1086      * runtime based on the current user. Primarily this concerns whether the user can access
1087      * the module or not.
1088      *
1089      * As part of this function, the module's _cm_info_dynamic function from its lib.php will
1090      * be called (if it exists).
1091      * @return void
1092      */
1093     public function obtain_dynamic_data() {
1094         global $CFG;
1095         if ($this->state >= self::STATE_DYNAMIC) {
1096             return;
1097         }
1098         $userid = $this->modinfo->get_user_id();
1099
1100         if (!empty($CFG->enableavailability)) {
1101             // Get availability information
1102             $ci = new condition_info($this);
1103             // Note that the modinfo currently available only includes minimal details (basic data)
1104             // so passing it to this function is a bit dangerous as it would cause infinite
1105             // recursion if it tried to get dynamic data, however we know that this function only
1106             // uses basic data.
1107             $this->available = $ci->is_available($this->availableinfo, true,
1108                     $userid, $this->modinfo);
1109
1110             // Check parent section
1111             $parentsection = $this->modinfo->get_section_info($this->sectionnum);
1112             if (!$parentsection->available) {
1113                 // Do not store info from section here, as that is already
1114                 // presented from the section (if appropriate) - just change
1115                 // the flag
1116                 $this->available = false;
1117             }
1118         } else {
1119             $this->available = true;
1120         }
1121
1122         // Update visible state for current user
1123         $this->update_user_visible();
1124
1125         // Let module make dynamic changes at this point
1126         $this->call_mod_function('cm_info_dynamic');
1127         $this->state = self::STATE_DYNAMIC;
1128     }
1129
1130     /**
1131      * Works out whether activity is available to the current user
1132      *
1133      * If the activity is unavailable, additional checks are required to determine if its hidden or greyed out
1134      *
1135      * @see is_user_access_restricted_by_group()
1136      * @see is_user_access_restricted_by_conditional_access()
1137      * @return void
1138      */
1139     private function update_user_visible() {
1140         global $CFG;
1141         $modcontext = context_module::instance($this->id);
1142         $userid = $this->modinfo->get_user_id();
1143         $this->uservisible = true;
1144
1145         // If the user cannot access the activity set the uservisible flag to false.
1146         // Additional checks are required to determine whether the activity is entirely hidden or just greyed out.
1147         if ((!$this->visible or !$this->available) and
1148                 !has_capability('moodle/course:viewhiddenactivities', $modcontext, $userid)) {
1149
1150             $this->uservisible = false;
1151         }
1152
1153         // Check group membership.
1154         if ($this->is_user_access_restricted_by_group()) {
1155
1156              $this->uservisible = false;
1157             // Ensure activity is completely hidden from the user.
1158             $this->showavailability = 0;
1159         }
1160     }
1161
1162     /**
1163      * Checks whether the module's group settings restrict the current user's access
1164      *
1165      * @return bool True if the user access is restricted
1166      */
1167     public function is_user_access_restricted_by_group() {
1168         global $CFG;
1169
1170         if (!empty($CFG->enablegroupmembersonly) and !empty($this->groupmembersonly)) {
1171             $modcontext = context_module::instance($this->id);
1172             $userid = $this->modinfo->get_user_id();
1173             if (!has_capability('moodle/site:accessallgroups', $modcontext, $userid)) {
1174                 // If the activity has 'group members only' and you don't have accessallgroups...
1175                 $groups = $this->modinfo->get_groups($this->groupingid);
1176                 if (empty($groups)) {
1177                     // ...and you don't belong to a group, then set it so you can't see/access it
1178                     return true;
1179                 }
1180             }
1181         }
1182         return false;
1183     }
1184
1185     /**
1186      * Checks whether the module's conditional access settings mean that the user cannot see the activity at all
1187      *
1188      * @return bool True if the user cannot see the module. False if the activity is either available or should be greyed out.
1189      */
1190     public function is_user_access_restricted_by_conditional_access() {
1191         global $CFG, $USER;
1192
1193         if (empty($CFG->enableavailability)) {
1194             return false;
1195         }
1196
1197         // If module will always be visible anyway (but greyed out), don't bother checking anything else
1198         if ($this->showavailability == CONDITION_STUDENTVIEW_SHOW) {
1199             return false;
1200         }
1201
1202         // Can the user see hidden modules?
1203         $modcontext = context_module::instance($this->id);
1204         $userid = $this->modinfo->get_user_id();
1205         if (has_capability('moodle/course:viewhiddenactivities', $modcontext, $userid)) {
1206             return false;
1207         }
1208
1209         // Is the module hidden due to unmet conditions?
1210         if (!$this->available) {
1211             return true;
1212         }
1213
1214         return false;
1215     }
1216
1217     /**
1218      * Calls a module function (if exists), passing in one parameter: this object.
1219      * @param string $type Name of function e.g. if this is 'grooblezorb' and the modname is
1220      *   'forum' then it will try to call 'mod_forum_grooblezorb' or 'forum_grooblezorb'
1221      * @return void
1222      */
1223     private function call_mod_function($type) {
1224         global $CFG;
1225         $libfile = $CFG->dirroot . '/mod/' . $this->modname . '/lib.php';
1226         if (file_exists($libfile)) {
1227             include_once($libfile);
1228             $function = 'mod_' . $this->modname . '_' . $type;
1229             if (function_exists($function)) {
1230                 $function($this);
1231             } else {
1232                 $function = $this->modname . '_' . $type;
1233                 if (function_exists($function)) {
1234                     $function($this);
1235                 }
1236             }
1237         }
1238     }
1239
1240     /**
1241      * If view data for this course-module is not yet available, obtains it.
1242      *
1243      * This function is automatically called if any of the functions (marked) which require
1244      * view data are called.
1245      *
1246      * View data is data which is needed only for displaying the course main page (& any similar
1247      * functionality on other pages) but is not needed in general. Obtaining view data may have
1248      * a performance cost.
1249      *
1250      * As part of this function, the module's _cm_info_view function from its lib.php will
1251      * be called (if it exists).
1252      * @return void
1253      */
1254     private function obtain_view_data() {
1255         if ($this->state >= self::STATE_VIEW) {
1256             return;
1257         }
1258
1259         // Let module make changes at this point
1260         $this->call_mod_function('cm_info_view');
1261         $this->state = self::STATE_VIEW;
1262     }
1263 }
1264
1265
1266 /**
1267  * Returns reference to full info about modules in course (including visibility).
1268  * Cached and as fast as possible (0 or 1 db query).
1269  *
1270  * use get_fast_modinfo($courseid, 0, true) to reset the static cache for particular course
1271  * use get_fast_modinfo(0, 0, true) to reset the static cache for all courses
1272  *
1273  * @uses MAX_MODINFO_CACHE_SIZE
1274  * @param int|stdClass $courseorid object from DB table 'course' or just a course id
1275  * @param int $userid User id to populate 'uservisible' attributes of modules and sections.
1276  *     Set to 0 for current user (default)
1277  * @param bool $resetonly whether we want to get modinfo or just reset the cache
1278  * @return course_modinfo|null Module information for course, or null if resetting
1279  */
1280 function get_fast_modinfo($courseorid, $userid = 0, $resetonly = false) {
1281     global $CFG, $USER;
1282     require_once($CFG->dirroot.'/course/lib.php');
1283
1284     if (!empty($CFG->enableavailability)) {
1285         require_once($CFG->libdir.'/conditionlib.php');
1286     }
1287
1288     static $cache = array();
1289
1290     // compartibility with syntax prior to 2.4:
1291     if ($courseorid === 'reset') {
1292         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);
1293         $courseorid = 0;
1294         $resetonly = true;
1295     }
1296
1297     if (is_object($courseorid)) {
1298         $course = $courseorid;
1299     } else {
1300         $course = (object)array('id' => $courseorid, 'modinfo' => null, 'sectioncache' => null);
1301     }
1302
1303     // Function is called with $reset = true
1304     if ($resetonly) {
1305         if (isset($course->id) && $course->id > 0) {
1306             $cache[$course->id] = false;
1307         } else {
1308             foreach (array_keys($cache) as $key) {
1309                 $cache[$key] = false;
1310             }
1311         }
1312         return null;
1313     }
1314
1315     // Function is called with $reset = false, retrieve modinfo
1316     if (empty($userid)) {
1317         $userid = $USER->id;
1318     }
1319
1320     if (array_key_exists($course->id, $cache)) {
1321         if ($cache[$course->id] === false) {
1322             // this course has been recently reset, do not rely on modinfo and sectioncache in $course
1323             $course->modinfo = null;
1324             $course->sectioncache = null;
1325         } else if ($cache[$course->id]->userid == $userid) {
1326             // this course's modinfo for the same user was recently retrieved, return cached
1327             return $cache[$course->id];
1328         }
1329     }
1330
1331     if (!property_exists($course, 'modinfo')) {
1332         debugging('Coding problem - missing course modinfo property in get_fast_modinfo() call');
1333     }
1334
1335     if (!property_exists($course, 'sectioncache')) {
1336         debugging('Coding problem - missing course sectioncache property in get_fast_modinfo() call');
1337     }
1338
1339     unset($cache[$course->id]); // prevent potential reference problems when switching users
1340
1341     $cache[$course->id] = new course_modinfo($course, $userid);
1342
1343     // Ensure cache does not use too much RAM
1344     if (count($cache) > MAX_MODINFO_CACHE_SIZE) {
1345         reset($cache);
1346         $key = key($cache);
1347         unset($cache[$key]->instances);
1348         unset($cache[$key]->cms);
1349         unset($cache[$key]);
1350     }
1351
1352     return $cache[$course->id];
1353 }
1354
1355 /**
1356  * Rebuilds the cached list of course activities stored in the database
1357  * @param int $courseid - id of course to rebuild, empty means all
1358  * @param boolean $clearonly - only clear the modinfo fields, gets rebuild automatically on the fly
1359  */
1360 function rebuild_course_cache($courseid=0, $clearonly=false) {
1361     global $COURSE, $SITE, $DB, $CFG;
1362
1363     if (!$clearonly && !empty($CFG->upgraderunning)) {
1364         debugging('Function rebuild_course_cache() should not be called from upgrade script unless with argument clearonly.',
1365                 DEBUG_DEVELOPER);
1366         $clearonly = true;
1367     }
1368
1369     // Destroy navigation caches
1370     navigation_cache::destroy_volatile_caches();
1371
1372     if (class_exists('format_base')) {
1373         // if file containing class is not loaded, there is no cache there anyway
1374         format_base::reset_course_cache($courseid);
1375     }
1376
1377     if ($clearonly) {
1378         if (empty($courseid)) {
1379             $DB->set_field('course', 'modinfo', null);
1380             $DB->set_field('course', 'sectioncache', null);
1381         } else {
1382             // Clear both fields in one update
1383             $resetobj = (object)array('id' => $courseid, 'modinfo' => null, 'sectioncache' => null);
1384             $DB->update_record('course', $resetobj);
1385         }
1386         // update cached global COURSE too ;-)
1387         if ($courseid == $COURSE->id or empty($courseid)) {
1388             $COURSE->modinfo = null;
1389             $COURSE->sectioncache = null;
1390         }
1391         if ($courseid == $SITE->id) {
1392             $SITE->modinfo = null;
1393             $SITE->sectioncache = null;
1394         }
1395         // reset the fast modinfo cache
1396         get_fast_modinfo($courseid, 0, true);
1397         return;
1398     }
1399
1400     require_once("$CFG->dirroot/course/lib.php");
1401
1402     if ($courseid) {
1403         $select = array('id'=>$courseid);
1404     } else {
1405         $select = array();
1406         @set_time_limit(0);  // this could take a while!   MDL-10954
1407     }
1408
1409     $rs = $DB->get_recordset("course", $select,'','id,fullname');
1410     foreach ($rs as $course) {
1411         $modinfo = serialize(get_array_of_activities($course->id));
1412         $sectioncache = serialize(course_modinfo::build_section_cache($course->id));
1413         $updateobj = (object)array('id' => $course->id,
1414                 'modinfo' => $modinfo, 'sectioncache' => $sectioncache);
1415         $DB->update_record("course", $updateobj);
1416         // update cached global COURSE too ;-)
1417         if ($course->id == $COURSE->id) {
1418             $COURSE->modinfo = $modinfo;
1419             $COURSE->sectioncache = $sectioncache;
1420         }
1421         if ($course->id == $SITE->id) {
1422             $SITE->modinfo = $modinfo;
1423             $SITE->sectioncache = $sectioncache;
1424         }
1425     }
1426     $rs->close();
1427     // reset the fast modinfo cache
1428     get_fast_modinfo($courseid, 0, true);
1429 }
1430
1431
1432 /**
1433  * Class that is the return value for the _get_coursemodule_info module API function.
1434  *
1435  * Note: For backward compatibility, you can also return a stdclass object from that function.
1436  * The difference is that the stdclass object may contain an 'extra' field (deprecated because
1437  * it was crazy, except for label which uses it differently). The stdclass object may not contain
1438  * the new fields defined here (content, extraclasses, customdata).
1439  */
1440 class cached_cm_info {
1441     /**
1442      * Name (text of link) for this activity; Leave unset to accept default name
1443      * @var string
1444      */
1445     public $name;
1446
1447     /**
1448      * Name of icon for this activity. Normally, this should be used together with $iconcomponent
1449      * to define the icon, as per pix_url function.
1450      * For backward compatibility, if this value is of the form 'mod/forum/icon' then an icon
1451      * within that module will be used.
1452      * @see cm_info::get_icon_url()
1453      * @see renderer_base::pix_url()
1454      * @var string
1455      */
1456     public $icon;
1457
1458     /**
1459      * Component for icon for this activity, as per pix_url; leave blank to use default 'moodle'
1460      * component
1461      * @see renderer_base::pix_url()
1462      * @var string
1463      */
1464     public $iconcomponent;
1465
1466     /**
1467      * HTML content to be displayed on the main page below the link (if any) for this course-module
1468      * @var string
1469      */
1470     public $content;
1471
1472     /**
1473      * Custom data to be stored in modinfo for this activity; useful if there are cases when
1474      * internal information for this activity type needs to be accessible from elsewhere on the
1475      * course without making database queries. May be of any type but should be short.
1476      * @var mixed
1477      */
1478     public $customdata;
1479
1480     /**
1481      * Extra CSS class or classes to be added when this activity is displayed on the main page;
1482      * space-separated string
1483      * @var string
1484      */
1485     public $extraclasses;
1486
1487     /**
1488      * External URL image to be used by activity as icon, useful for some external-tool modules
1489      * like lti. If set, takes precedence over $icon and $iconcomponent
1490      * @var $moodle_url
1491      */
1492     public $iconurl;
1493
1494     /**
1495      * Content of onclick JavaScript; escaped HTML to be inserted as attribute value
1496      * @var string
1497      */
1498     public $onclick;
1499 }
1500
1501
1502 /**
1503  * Data about a single section on a course. This contains the fields from the
1504  * course_sections table, plus additional data when required.
1505  */
1506 class section_info implements IteratorAggregate {
1507     /**
1508      * Section ID - from course_sections table
1509      * @var int
1510      */
1511     private $_id;
1512
1513     /**
1514      * Course ID - from course_sections table
1515      * @var int
1516      */
1517     private $_course;
1518
1519     /**
1520      * Section number - from course_sections table
1521      * @var int
1522      */
1523     private $_section;
1524
1525     /**
1526      * Section name if specified - from course_sections table
1527      * @var string
1528      */
1529     private $_name;
1530
1531     /**
1532      * Section visibility (1 = visible) - from course_sections table
1533      * @var int
1534      */
1535     private $_visible;
1536
1537     /**
1538      * Section summary text if specified - from course_sections table
1539      * @var string
1540      */
1541     private $_summary;
1542
1543     /**
1544      * Section summary text format (FORMAT_xx constant) - from course_sections table
1545      * @var int
1546      */
1547     private $_summaryformat;
1548
1549     /**
1550      * When section is unavailable, this field controls whether it is shown to students (0 =
1551      * hide completely, 1 = show greyed out with information about when it will be available) -
1552      * from course_sections table
1553      * @var int
1554      */
1555     private $_showavailability;
1556
1557     /**
1558      * Available date for this section (0 if not set, or set to seconds since epoch; before this
1559      * date, section does not display to students) - from course_sections table
1560      * @var int
1561      */
1562     private $_availablefrom;
1563
1564     /**
1565      * Available until date for this section  (0 if not set, or set to seconds since epoch; from
1566      * this date, section does not display to students) - from course_sections table
1567      * @var int
1568      */
1569     private $_availableuntil;
1570
1571     /**
1572      * If section is restricted to users of a particular grouping, this is its id
1573      * (0 if not set) - from course_sections table
1574      * @var int
1575      */
1576     private $_groupingid;
1577
1578     /**
1579      * Availability conditions for this section based on the completion of
1580      * course-modules (array from course-module id to required completion state
1581      * for that module) - from cached data in sectioncache field
1582      * @var array
1583      */
1584     private $_conditionscompletion;
1585
1586     /**
1587      * Availability conditions for this section based on course grades (array from
1588      * grade item id to object with ->min, ->max fields) - from cached data in
1589      * sectioncache field
1590      * @var array
1591      */
1592     private $_conditionsgrade;
1593
1594     /**
1595      * Availability conditions for this section based on user fields
1596      * @var array
1597      */
1598     private $_conditionsfield;
1599
1600     /**
1601      * True if this section is available to students i.e. if all availability conditions
1602      * are met - obtained dynamically
1603      * @var bool
1604      */
1605     private $_available;
1606
1607     /**
1608      * If section is not available to students, this string gives information about
1609      * availability which can be displayed to students and/or staff (e.g. 'Available from 3
1610      * January 2010') for display on main page - obtained dynamically
1611      * @var string
1612      */
1613     private $_availableinfo;
1614
1615     /**
1616      * True if this section is available to the CURRENT user (for example, if current user
1617      * has viewhiddensections capability, they can access the section even if it is not
1618      * visible or not available, so this would be true in that case)
1619      * @var bool
1620      */
1621     private $_uservisible;
1622
1623     /**
1624      * Default values for sectioncache fields; if a field has this value, it won't
1625      * be stored in the sectioncache cache, to save space. Checks are done by ===
1626      * which means values must all be strings.
1627      * @var array
1628      */
1629     private static $sectioncachedefaults = array(
1630         'name' => null,
1631         'summary' => '',
1632         'summaryformat' => '1', // FORMAT_HTML, but must be a string
1633         'visible' => '1',
1634         'showavailability' => '0',
1635         'availablefrom' => '0',
1636         'availableuntil' => '0',
1637         'groupingid' => '0',
1638     );
1639
1640     /**
1641      * Stores format options that have been cached when building 'coursecache'
1642      * When the format option is requested we look first if it has been cached
1643      * @var array
1644      */
1645     private $cachedformatoptions = array();
1646
1647     /**
1648      * Constructs object from database information plus extra required data.
1649      * @param object $data Array entry from cached sectioncache
1650      * @param int $number Section number (array key)
1651      * @param int $courseid Course ID
1652      * @param int $sequence Sequence of course-module ids contained within
1653      * @param course_modinfo $modinfo Owner (needed for checking availability)
1654      * @param int $userid User ID
1655      */
1656     public function __construct($data, $number, $courseid, $sequence, $modinfo, $userid) {
1657         global $CFG;
1658
1659         // Data that is always present
1660         $this->_id = $data->id;
1661
1662         $defaults = self::$sectioncachedefaults +
1663                 array('conditionscompletion' => array(),
1664                     'conditionsgrade' => array(),
1665                     'conditionsfield' => array());
1666
1667         // Data that may use default values to save cache size
1668         foreach ($defaults as $field => $value) {
1669             if (isset($data->{$field})) {
1670                 $this->{'_'.$field} = $data->{$field};
1671             } else {
1672                 $this->{'_'.$field} = $value;
1673             }
1674         }
1675
1676         // cached course format data
1677         $formatoptionsdef = course_get_format($courseid)->section_format_options();
1678         foreach ($formatoptionsdef as $field => $option) {
1679             if (!empty($option['cache'])) {
1680                 if (isset($data->{$field})) {
1681                     $this->cachedformatoptions[$field] = $data->{$field};
1682                 } else if (array_key_exists('cachedefault', $option)) {
1683                     $this->cachedformatoptions[$field] = $option['cachedefault'];
1684                 }
1685             }
1686         }
1687
1688         // Other data from other places
1689         $this->_course = $courseid;
1690         $this->_section = $number;
1691         $this->_sequence = $sequence;
1692
1693         // Availability data
1694         if (!empty($CFG->enableavailability)) {
1695             // Get availability information
1696             $ci = new condition_info_section($this);
1697             $this->_available = $ci->is_available($this->_availableinfo, true,
1698                     $userid, $modinfo);
1699             // Display grouping info if available & not already displaying
1700             // (it would already display if current user doesn't have access)
1701             // for people with managegroups - same logic/class as grouping label
1702             // on individual activities.
1703             $context = context_course::instance($courseid);
1704             if ($this->_availableinfo === '' && $this->_groupingid &&
1705                     has_capability('moodle/course:managegroups', $context)) {
1706                 $groupings = groups_get_all_groupings($courseid);
1707                 $this->_availableinfo = html_writer::tag('span', '(' . format_string(
1708                         $groupings[$this->_groupingid]->name, true, array('context' => $context)) .
1709                         ')', array('class' => 'groupinglabel'));
1710             }
1711         } else {
1712             $this->_available = true;
1713         }
1714
1715         // Update visibility for current user
1716         $this->update_user_visible($userid);
1717     }
1718
1719     /**
1720      * Magic method to check if the property is set
1721      *
1722      * @param string $name name of the property
1723      * @return bool
1724      */
1725     public function __isset($name) {
1726         if (property_exists($this, '_'.$name)) {
1727             return isset($this->{'_'.$name});
1728         }
1729         $defaultformatoptions = course_get_format($this->_course)->section_format_options();
1730         if (array_key_exists($name, $defaultformatoptions)) {
1731             $value = $this->__get($name);
1732             return isset($value);
1733         }
1734         return false;
1735     }
1736
1737     /**
1738      * Magic method to check if the property is empty
1739      *
1740      * @param string $name name of the property
1741      * @return bool
1742      */
1743     public function __empty($name) {
1744         if (property_exists($this, '_'.$name)) {
1745             return empty($this->{'_'.$name});
1746         }
1747         $defaultformatoptions = course_get_format($this->_course)->section_format_options();
1748         if (array_key_exists($name, $defaultformatoptions)) {
1749             $value = $this->__get($name);
1750             return empty($value);
1751         }
1752         return true;
1753     }
1754
1755     /**
1756      * Magic method to retrieve the property, this is either basic section property
1757      * or availability information or additional properties added by course format
1758      *
1759      * @param string $name name of the property
1760      * @return bool
1761      */
1762     public function __get($name) {
1763         if (property_exists($this, '_'.$name)) {
1764             return $this->{'_'.$name};
1765         }
1766         if (array_key_exists($name, $this->cachedformatoptions)) {
1767             return $this->cachedformatoptions[$name];
1768         }
1769         $defaultformatoptions = course_get_format($this->_course)->section_format_options();
1770         // precheck if the option is defined in format to avoid unnecessary DB queries in get_format_options()
1771         if (array_key_exists($name, $defaultformatoptions)) {
1772             $formatoptions = course_get_format($this->_course)->get_format_options($this);
1773             return $formatoptions[$name];
1774         }
1775         debugging('Invalid section_info property accessed! '.$name);
1776         return null;
1777     }
1778
1779     /**
1780      * Implementation of IteratorAggregate::getIterator(), allows to cycle through properties
1781      * and use {@link convert_to_array()}
1782      *
1783      * @return ArrayIterator
1784      */
1785     public function getIterator() {
1786         $ret = array();
1787         foreach (get_object_vars($this) as $key => $value) {
1788             if (substr($key, 0, 1) == '_') {
1789                 $ret[substr($key, 1)] = $this->$key;
1790             }
1791         }
1792         $ret = array_merge($ret, course_get_format($this->_course)->get_format_options($this));
1793         return new ArrayIterator($ret);
1794     }
1795
1796     /**
1797      * Works out whether activity is visible *for current user* - if this is false, they
1798      * aren't allowed to access it.
1799      * @param int $userid User ID
1800      * @return void
1801      */
1802     private function update_user_visible($userid) {
1803         global $CFG;
1804         $coursecontext = context_course::instance($this->_course);
1805         $this->_uservisible = true;
1806         if ((!$this->_visible || !$this->_available) &&
1807                 !has_capability('moodle/course:viewhiddensections', $coursecontext, $userid)) {
1808             $this->_uservisible = false;
1809         }
1810     }
1811
1812     /**
1813      * Prepares section data for inclusion in sectioncache cache, removing items
1814      * that are set to defaults, and adding availability data if required.
1815      *
1816      * Called by build_section_cache in course_modinfo only; do not use otherwise.
1817      * @param object $section Raw section data object
1818      */
1819     public static function convert_for_section_cache($section) {
1820         global $CFG;
1821
1822         // Course id stored in course table
1823         unset($section->course);
1824         // Section number stored in array key
1825         unset($section->section);
1826         // Sequence stored implicity in modinfo $sections array
1827         unset($section->sequence);
1828
1829         // Add availability data if turned on
1830         if ($CFG->enableavailability) {
1831             require_once($CFG->dirroot . '/lib/conditionlib.php');
1832             condition_info_section::fill_availability_conditions($section);
1833             if (count($section->conditionscompletion) == 0) {
1834                 unset($section->conditionscompletion);
1835             }
1836             if (count($section->conditionsgrade) == 0) {
1837                 unset($section->conditionsgrade);
1838             }
1839         }
1840
1841         // Remove default data
1842         foreach (self::$sectioncachedefaults as $field => $value) {
1843             // Exact compare as strings to avoid problems if some strings are set
1844             // to "0" etc.
1845             if (isset($section->{$field}) && $section->{$field} === $value) {
1846                 unset($section->{$field});
1847             }
1848         }
1849     }
1850 }