lib/completionlib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * Contains a class used for tracking whether activities have been completed
  20  * by students ('completion')
  21  *
  22  * Completion top-level options (admin setting enablecompletion)
  23  *
  24  * @package    core
  25  * @subpackage completion
  26  * @copyright  1999 onwards Martin Dougiamas   {@link http://moodle.com}
  27  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  28  */
  29
  30 defined('MOODLE_INTERNAL') || die();
  31
  32 require_once $CFG->libdir.'/completion/completion_aggregation.php';
  33 require_once $CFG->libdir.'/completion/completion_criteria.php';
  34 require_once $CFG->libdir.'/completion/completion_completion.php';
  35 require_once $CFG->libdir.'/completion/completion_criteria_completion.php';
  36
  37
  38 /** The completion system is enabled in this site/course */
  39 define('COMPLETION_ENABLED', 1);
  40 /** The completion system is not enabled in this site/course */
  41 define('COMPLETION_DISABLED', 0);
  42
  43 // Completion tracking options per-activity (course_modules/completion)
  44
  45 /** Completion tracking is disabled for this activity */
  46 define('COMPLETION_TRACKING_NONE', 0);
  47 /** Manual completion tracking (user ticks box) is enabled for this activity */
  48 define('COMPLETION_TRACKING_MANUAL', 1);
  49 /** Automatic completion tracking (system ticks box) is enabled for this activity */
  50 define('COMPLETION_TRACKING_AUTOMATIC', 2);
  51
  52 // Completion state values (course_modules_completion/completionstate)
  53
  54 /** The user has not completed this activity. */
  55 define('COMPLETION_INCOMPLETE', 0);
  56 /** The user has completed this activity. It is not specified whether they have
  57  * passed or failed it. */
  58 define('COMPLETION_COMPLETE', 1);
  59 /** The user has completed this activity with a grade above the pass mark. */
  60 define('COMPLETION_COMPLETE_PASS', 2);
  61 /** The user has completed this activity but their grade is less than the pass mark */
  62 define('COMPLETION_COMPLETE_FAIL', 3);
  63
  64 // Completion effect changes (used only in update_state)
  65
  66 /** The effect of this change to completion status is unknown. */
  67 define('COMPLETION_UNKNOWN', -1);
  68 /** The user's grade has changed, so their new state might be
  69  * COMPLETION_COMPLETE_PASS or COMPLETION_COMPLETE_FAIL. */
  70 // TODO Is this useful?
  71 define('COMPLETION_GRADECHANGE', -2);
  72
  73 // Whether view is required to create an activity (course_modules/completionview)
  74
  75 /** User must view this activity */
  76 define('COMPLETION_VIEW_REQUIRED', 1);
  77 /** User does not need to view this activity */
  78 define('COMPLETION_VIEW_NOT_REQUIRED', 0);
  79
  80 // Completion viewed state (course_modules_completion/viewed)
  81
  82 /** User has viewed this activity */
  83 define('COMPLETION_VIEWED', 1);
  84 /** User has not viewed this activity */
  85 define('COMPLETION_NOT_VIEWED', 0);
  86
  87 // Completion cacheing
  88
  89 /** Cache expiry time in seconds (10 minutes) */
  90 define('COMPLETION_CACHE_EXPIRY', 10*60);
  91
  92 // Combining completion condition. This is also the value you should return
  93 // if you don't have any applicable conditions. Used for activity completion.
  94 /** Completion details should be ORed together and you should return false if
  95  none apply */
  96 define('COMPLETION_OR', false);
  97 /** Completion details should be ANDed together and you should return true if
  98  none apply */
  99 define('COMPLETION_AND', true);
 100
 101 // Course completion criteria aggregation methods
 102 define('COMPLETION_AGGREGATION_ALL',        1);
 103 define('COMPLETION_AGGREGATION_ANY',        2);
 104
 105
 106 /**
 107  * Class represents completion information for a course.
 108  *
 109  * Does not contain any data, so you can safely construct it multiple times
 110  * without causing any problems.
 111  *
 112  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 113  * @package moodlecore
 114  */
 115 class completion_info {
 116     /**
 117      * Course object passed during construction
 118      * @access  private
 119      * @var     object
 120      */
 121     private $course;
 122
 123     /**
 124      * Course id
 125      * @access  public
 126      * @var     int
 127      */
 128     public $course_id;
 129
 130     /**
 131      * Completion criteria
 132      * @access  private
 133      * @var     array
 134      * @see     completion_info->get_criteria()
 135      */
 136     private $criteria;
 137
 138     /**
 139      * Return array of aggregation methods
 140      * @access  public
 141      * @return  array
 142      */
 143     public static function get_aggregation_methods() {
 144         return array(
 145             COMPLETION_AGGREGATION_ALL       => get_string('all'),
 146             COMPLETION_AGGREGATION_ANY       => get_string('any', 'completion'),
 147         );
 148     }
 149
 150     /**
 151      * Constructs with course details.
 152      *
 153      * @param object $course Moodle course object. Must have at least ->id, ->enablecompletion
 154      */
 155     public function __construct($course) {
 156         $this->course = $course;
 157         $this->course_id = $course->id;
 158     }
 159
 160     /**
 161      * Determines whether completion is enabled across entire site.
 162      *
 163      * Static function.
 164      *
 165      * @global object
 166      * @return int COMPLETION_ENABLED (true) if completion is enabled for the site,
 167      *     COMPLETION_DISABLED (false) if it's complete
 168      */
 169     public static function is_enabled_for_site() {
 170         global $CFG;
 171         return !empty($CFG->enablecompletion);
 172     }
 173
 174     /**
 175      * Checks whether completion is enabled in a particular course and possibly
 176      * activity.
 177      *
 178      * @global object
 179      * @uses COMPLETION_DISABLED
 180      * @uses COMPLETION_ENABLED
 181      * @param object $cm Course-module object. If not specified, returns the course
 182      *   completion enable state.
 183      * @return mixed COMPLETION_ENABLED or COMPLETION_DISABLED (==0) in the case of
 184      *   site and course; COMPLETION_TRACKING_MANUAL, _AUTOMATIC or _NONE (==0)
 185      *   for a course-module.
 186      */
 187     public function is_enabled($cm=null) {
 188         global $CFG, $DB;
 189
 190         // First check global completion
 191         if (!isset($CFG->enablecompletion) || $CFG->enablecompletion == COMPLETION_DISABLED) {
 192             return COMPLETION_DISABLED;
 193         }
 194
 195         // Load data if we do not have enough
 196         if (!isset($this->course->enablecompletion)) {
 197             $this->course->enablecompletion = $DB->get_field('course', 'enablecompletion', array('id' => $this->course->id));
 198         }
 199
 200         // Check course completion
 201         if ($this->course->enablecompletion == COMPLETION_DISABLED) {
 202             return COMPLETION_DISABLED;
 203         }
 204
 205         // If there was no $cm and we got this far, then it's enabled
 206         if (!$cm) {
 207             return COMPLETION_ENABLED;
 208         }
 209
 210         // Return course-module completion value
 211         return $cm->completion;
 212     }
 213
 214     /**
 215      * Displays the 'Your progress' help icon, if completion tracking is enabled.
 216      * Just prints the result of display_help_icon().
 217      * @deprecated Use display_help_icon instead.
 218      * @return void
 219      */
 220     public function print_help_icon() {
 221         print $this->display_help_icon();
 222     }
 223
 224     /**
 225      * Returns the 'Your progress' help icon, if completion tracking is enabled.
 226      * @global object
 227      * @return string HTML code for help icon, or blank if not needed
 228      */
 229     public function display_help_icon() {
 230         global $PAGE, $OUTPUT;
 231         $result = '';
 232         if ($this->is_enabled() && !$PAGE->user_is_editing() && isloggedin() && !isguestuser()) {
 233             $result .= '<span id = "completionprogressid" class="completionprogress">'.get_string('yourprogress','completion').' ';
 234             $result .= $OUTPUT->help_icon('completionicons', 'completion');
 235             $result .= '</span>';
 236         }
 237         return $result;
 238     }
 239
 240     /**
 241      * Get a course completion for a user
 242      * @access  public
 243      * @param   $user_id        int     User id
 244      * @param   $criteriatype   int     Specific criteria type to return
 245      * @return  false|completion_criteria_completion
 246      */
 247     public function get_completion($user_id, $criteriatype) {
 248         $completions = $this->get_completions($user_id, $criteriatype);
 249
 250         if (empty($completions)) {
 251             return false;
 252         } elseif (count($completions) > 1) {
 253             print_error('multipleselfcompletioncriteria', 'completion');
 254         }
 255
 256         return $completions[0];
 257     }
 258
 259     /**
 260      * Get all course criteria's completion objects for a user
 261      * @access  public
 262      * @param   $user_id        int     User id
 263      * @param   $criteriatype   int     optional    Specific criteria type to return
 264      * @return  array
 265      */
 266     public function get_completions($user_id, $criteriatype = null) {
 267         $criterion = $this->get_criteria($criteriatype);
 268
 269         $completions = array();
 270
 271         foreach ($criterion as $criteria) {
 272             $params = array(
 273                 'course'        => $this->course_id,
 274                 'userid'        => $user_id,
 275                 'criteriaid'    => $criteria->id
 276             );
 277
 278             $completion = new completion_criteria_completion($params);
 279             $completion->attach_criteria($criteria);
 280
 281             $completions[] = $completion;
 282         }
 283
 284         return $completions;
 285     }
 286
 287     /**
 288      * Get completion object for a user and a criteria
 289      * @access  public
 290      * @param   $user_id        int     User id
 291      * @param   $criteria       completion_criteria     Criteria object
 292      * @return  completion_criteria_completion
 293      */
 294     public function get_user_completion($user_id, $criteria) {
 295         $params = array(
 296             'course'        => $this->course_id,
 297             'userid'        => $user_id,
 298             'criteriaid'    => $criteria->id,
 299         );
 300
 301         $completion = new completion_criteria_completion($params);
 302         return $completion;
 303     }
 304
 305     /**
 306      * Check if course has completion criteria set
 307      *
 308      * @access  public
 309      * @return  bool
 310      */
 311     public function has_criteria() {
 312         $criteria = $this->get_criteria();
 313
 314         return (bool) count($criteria);
 315     }
 316
 317
 318     /**
 319      * Get course completion criteria
 320      * @access  public
 321      * @param   $criteriatype   int     optional    Specific criteria type to return
 322      * @return  void
 323      */
 324     public function get_criteria($criteriatype = null) {
 325
 326         // Fill cache if empty
 327         if (!is_array($this->criteria)) {
 328             global $DB;
 329
 330             $params = array(
 331                 'course'    => $this->course->id
 332             );
 333
 334             // Load criteria from database
 335             $records = (array)$DB->get_records('course_completion_criteria', $params);
 336
 337             // Build array of criteria objects
 338             $this->criteria = array();
 339             foreach ($records as $record) {
 340                 $this->criteria[$record->id] = completion_criteria::factory((array)$record);
 341             }
 342         }
 343
 344         // If after all criteria
 345         if ($criteriatype === null) {
 346             return $this->criteria;
 347         }
 348
 349         // If we are only after a specific criteria type
 350         $criteria = array();
 351         foreach ($this->criteria as $criterion) {
 352
 353             if ($criterion->criteriatype != $criteriatype) {
 354                 continue;
 355             }
 356
 357             $criteria[$criterion->id] = $criterion;
 358         }
 359
 360         return $criteria;
 361     }
 362
 363     /**
 364      * Get aggregation method
 365      * @access  public
 366      * @param   $criteriatype   int     optional    If none supplied, get overall aggregation method
 367      * @return  int
 368      */
 369     public function get_aggregation_method($criteriatype = null) {
 370         $params = array(
 371             'course'        => $this->course_id,
 372             'criteriatype'  => $criteriatype
 373         );
 374
 375         $aggregation = new completion_aggregation($params);
 376
 377         if (!$aggregation->id) {
 378             $aggregation->method = COMPLETION_AGGREGATION_ALL;
 379         }
 380
 381         return $aggregation->method;
 382     }
 383
 384     /**
 385      * Get incomplete course completion criteria
 386      * @access  public
 387      * @return  void
 388      */
 389     public function get_incomplete_criteria() {
 390         $incomplete = array();
 391
 392         foreach ($this->get_criteria() as $criteria) {
 393             if (!$criteria->is_complete()) {
 394                 $incomplete[] = $criteria;
 395             }
 396         }
 397
 398         return $incomplete;
 399     }
 400
 401     /**
 402      * Clear old course completion criteria
 403      */
 404     public function clear_criteria() {
 405         global $DB;
 406         $DB->delete_records('course_completion_criteria', array('course' => $this->course_id));
 407         $DB->delete_records('course_completion_aggr_methd', array('course' => $this->course_id));
 408
 409         $this->delete_course_completion_data();
 410     }
 411
 412     /**
 413      * Has the supplied user completed this course
 414      * @access  public
 415      * @param   $user_id    int     User's id
 416      * @return  boolean
 417      */
 418     public function is_course_complete($user_id) {
 419         $params = array(
 420             'userid'    => $user_id,
 421             'course'  => $this->course_id
 422         );
 423
 424         $ccompletion = new completion_completion($params);
 425         return $ccompletion->is_complete();
 426     }
 427
 428     /**
 429      * Updates (if necessary) the completion state of activity $cm for the given
 430      * user.
 431      *
 432      * For manual completion, this function is called when completion is toggled
 433      * with $possibleresult set to the target state.
 434      *
 435      * For automatic completion, this function should be called every time a module
 436      * does something which might influence a user's completion state. For example,
 437      * if a forum provides options for marking itself 'completed' once a user makes
 438      * N posts, this function should be called every time a user makes a new post.
 439      * [After the post has been saved to the database]. When calling, you do not
 440      * need to pass in the new completion state. Instead this function carries out
 441      * completion calculation by checking grades and viewed state itself, and
 442      * calling the involved module via modulename_get_completion_state() to check
 443      * module-specific conditions.
 444      *
 445      * @global object
 446      * @global object
 447      * @uses COMPLETION_COMPLETE
 448      * @uses COMPLETION_INCOMPLETE
 449      * @uses COMPLETION_COMPLETE_PASS
 450      * @uses COMPLETION_COMPLETE_FAIL
 451      * @uses COMPLETION_TRACKING_MANUAL
 452      * @param object $cm Course-module
 453      * @param int $possibleresult Expected completion result. If the event that
 454      *   has just occurred (e.g. add post) can only result in making the activity
 455      *   complete when it wasn't before, use COMPLETION_COMPLETE. If the event that
 456      *   has just occurred (e.g. delete post) can only result in making the activity
 457      *   not complete when it was previously complete, use COMPLETION_INCOMPLETE.
 458      *   Otherwise use COMPLETION_UNKNOWN. Setting this value to something other than
 459      *   COMPLETION_UNKNOWN significantly improves performance because it will abandon
 460      *   processing early if the user's completion state already matches the expected
 461      *   result. For manual events, COMPLETION_COMPLETE or COMPLETION_INCOMPLETE
 462      *   must be used; these directly set the specified state.
 463      * @param int $userid User ID to be updated. Default 0 = current user
 464      * @return void
 465      */
 466     public function update_state($cm, $possibleresult=COMPLETION_UNKNOWN, $userid=0) {
 467         global $USER, $SESSION;
 468
 469         // Do nothing if completion is not enabled for that activity
 470         if (!$this->is_enabled($cm)) {
 471             return;
 472         }
 473
 474         // Get current value of completion state and do nothing if it's same as
 475         // the possible result of this change. If the change is to COMPLETE and the
 476         // current value is one of the COMPLETE_xx subtypes, ignore that as well
 477         $current = $this->get_data($cm, false, $userid);
 478         if ($possibleresult == $current->completionstate ||
 479             ($possibleresult == COMPLETION_COMPLETE &&
 480                 ($current->completionstate == COMPLETION_COMPLETE_PASS ||
 481                 $current->completionstate == COMPLETION_COMPLETE_FAIL))) {
 482             return;
 483         }
 484
 485         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 486             // For manual tracking we set the result directly
 487             switch($possibleresult) {
 488                 case COMPLETION_COMPLETE:
 489                 case COMPLETION_INCOMPLETE:
 490                     $newstate = $possibleresult;
 491                     break;
 492                 default:
 493                     $this->internal_systemerror("Unexpected manual completion state for {$cm->id}: $possibleresult");
 494             }
 495
 496         } else {
 497             // Automatic tracking; get new state
 498             $newstate = $this->internal_get_state($cm, $userid, $current);
 499         }
 500
 501         // If changed, update
 502         if ($newstate != $current->completionstate) {
 503             $current->completionstate = $newstate;
 504             $current->timemodified    = time();
 505             $this->internal_set_data($cm, $current);
 506         }
 507     }
 508
 509     /**
 510      * Calculates the completion state for an activity and user.
 511      *
 512      * Internal function. Not private, so we can unit-test it.
 513      *
 514      * @global object
 515      * @global object
 516      * @global object
 517      * @uses COMPLETION_VIEW_REQUIRED
 518      * @uses COMPLETION_NOT_VIEWED
 519      * @uses COMPLETION_INCOMPLETE
 520      * @uses FEATURE_COMPLETION_HAS_RULES
 521      * @uses COMPLETION_COMPLETE
 522      * @uses COMPLETION_AND
 523      * @param object $cm Activity
 524      * @param int $userid ID of user
 525      * @param object $current Previous completion information from database
 526      * @return mixed
 527      */
 528     function internal_get_state($cm, $userid, $current) {
 529         global $USER, $DB, $CFG;
 530
 531         // Get user ID
 532         if (!$userid) {
 533             $userid = $USER->id;
 534         }
 535
 536         // Check viewed
 537         if ($cm->completionview == COMPLETION_VIEW_REQUIRED &&
 538             $current->viewed == COMPLETION_NOT_VIEWED) {
 539
 540             return COMPLETION_INCOMPLETE;
 541         }
 542
 543         // Modname hopefully is provided in $cm but just in case it isn't, let's grab it
 544         if (!isset($cm->modname)) {
 545             $cm->modname = $DB->get_field('modules', 'name', array('id'=>$cm->module));
 546         }
 547
 548         $newstate = COMPLETION_COMPLETE;
 549
 550         // Check grade
 551         if (!is_null($cm->completiongradeitemnumber)) {
 552             require_once($CFG->libdir.'/gradelib.php');
 553             $item = grade_item::fetch(array('courseid'=>$cm->course, 'itemtype'=>'mod',
 554                 'itemmodule'=>$cm->modname, 'iteminstance'=>$cm->instance,
 555                 'itemnumber'=>$cm->completiongradeitemnumber));
 556             if ($item) {
 557                 // Fetch 'grades' (will be one or none)
 558                 $grades = grade_grade::fetch_users_grades($item, array($userid), false);
 559                 if (empty($grades)) {
 560                     // No grade for user
 561                     return COMPLETION_INCOMPLETE;
 562                 }
 563                 if (count($grades) > 1) {
 564                     $this->internal_systemerror("Unexpected result: multiple grades for
 565                         item '{$item->id}', user '{$userid}'");
 566                 }
 567                 $newstate = $this->internal_get_grade_state($item, reset($grades));
 568                 if ($newstate == COMPLETION_INCOMPLETE) {
 569                     return COMPLETION_INCOMPLETE;
 570                 }
 571
 572             } else {
 573                 $this->internal_systemerror("Cannot find grade item for '{$cm->modname}'
 574                     cm '{$cm->id}' matching number '{$cm->completiongradeitemnumber}'");
 575             }
 576         }
 577
 578         if (plugin_supports('mod', $cm->modname, FEATURE_COMPLETION_HAS_RULES)) {
 579             $function = $cm->modname.'_get_completion_state';
 580             if (!function_exists($function)) {
 581                 $this->internal_systemerror("Module {$cm->modname} claims to support
 582                     FEATURE_COMPLETION_HAS_RULES but does not have required
 583                     {$cm->modname}_get_completion_state function");
 584             }
 585             if (!$function($this->course, $cm, $userid, COMPLETION_AND)) {
 586                 return COMPLETION_INCOMPLETE;
 587             }
 588         }
 589
 590         return $newstate;
 591
 592     }
 593
 594
 595     /**
 596      * Marks a module as viewed.
 597      *
 598      * Should be called whenever a module is 'viewed' (it is up to the module how to
 599      * determine that). Has no effect if viewing is not set as a completion condition.
 600      *
 601      * Note that this function must be called before you print the page header because
 602      * it is possible that the navigation block may depend on it. If you call it after
 603      * printing the header, it shows a developer debug warning.
 604      * @uses COMPLETION_VIEW_NOT_REQUIRED
 605      * @uses COMPLETION_VIEWED
 606      * @uses COMPLETION_COMPLETE
 607      * @param object $cm Activity
 608      * @param int $userid User ID or 0 (default) for current user
 609      * @return void
 610      */
 611     public function set_module_viewed($cm, $userid=0) {
 612         global $PAGE, $UNITTEST;
 613         if ($PAGE->headerprinted && empty($UNITTEST->running)) {
 614             debugging('set_module_viewed must be called before header is printed',
 615                     DEBUG_DEVELOPER);
 616         }
 617
 618         // Don't do anything if view condition is not turned on
 619         if ($cm->completionview == COMPLETION_VIEW_NOT_REQUIRED || !$this->is_enabled($cm)) {
 620             return;
 621         }
 622
 623         // Get current completion state
 624         $data = $this->get_data($cm, false, $userid);
 625
 626         // If we already viewed it, don't do anything
 627         if ($data->viewed == COMPLETION_VIEWED) {
 628             return;
 629         }
 630
 631         // OK, change state, save it, and update completion
 632         $data->viewed = COMPLETION_VIEWED;
 633         $this->internal_set_data($cm, $data);
 634         $this->update_state($cm, COMPLETION_COMPLETE, $userid);
 635     }
 636
 637     /**
 638      * Determines how much completion data exists for an activity. This is used when
 639      * deciding whether completion information should be 'locked' in the module
 640      * editing form.
 641      *
 642      * @global object
 643      * @param object $cm Activity
 644      * @return int The number of users who have completion data stored for this
 645      *   activity, 0 if none
 646      */
 647     public function count_user_data($cm) {
 648         global $DB;
 649
 650         return $DB->get_field_sql("
 651     SELECT
 652         COUNT(1)
 653     FROM
 654         {course_modules_completion}
 655     WHERE
 656         coursemoduleid=? AND completionstate<>0", array($cm->id));
 657     }
 658
 659     /**
 660      * Determines how much course completion data exists for a course. This is used when
 661      * deciding whether completion information should be 'locked' in the completion
 662      * settings form and activity completion settings.
 663      *
 664      * @global object
 665      * @param  int $user_id Optionally only get course completion data for a single user
 666      * @return int The number of users who have completion data stored for this
 667      *   course, 0 if none
 668      */
 669     public function count_course_user_data($user_id = null) {
 670         global $DB;
 671
 672         $sql = '
 673     SELECT
 674         COUNT(1)
 675     FROM
 676         {course_completion_crit_compl}
 677     WHERE
 678         course = ?
 679         ';
 680
 681         $params = array($this->course_id);
 682
 683         // Limit data to a single user if an ID is supplied
 684         if ($user_id) {
 685             $sql .= ' AND userid = ?';
 686             $params[] = $user_id;
 687         }
 688
 689         return $DB->get_field_sql($sql, $params);
 690     }
 691
 692     /**
 693      * Check if this course's completion criteria should be locked
 694      *
 695      * @return  boolean
 696      */
 697     public function is_course_locked() {
 698         return (bool) $this->count_course_user_data();
 699     }
 700
 701     /**
 702      * Deletes all course completion completion data.
 703      *
 704      * Intended to be used when unlocking completion criteria settings.
 705      *
 706      * @global  object
 707      * @return  void
 708      */
 709     public function delete_course_completion_data() {
 710         global $DB;
 711
 712         $DB->delete_records('course_completions', array('course' => $this->course_id));
 713         $DB->delete_records('course_completion_crit_compl', array('course' => $this->course_id));
 714     }
 715
 716     /**
 717      * Deletes all activity and course completion data for an entire course
 718      * (the below delete_all_state function does this for a single activity).
 719      *
 720      * Used by course reset page.
 721      */
 722     public function delete_all_completion_data() {
 723         global $DB, $SESSION;
 724
 725         // Delete from database.
 726         $DB->delete_records_select('course_modules_completion',
 727                 'coursemoduleid IN (SELECT id FROM {course_modules} WHERE course=?)',
 728                 array($this->course_id));
 729
 730         // Reset cache for current user.
 731         if (isset($SESSION->completioncache) &&
 732             array_key_exists($this->course_id, $SESSION->completioncache)) {
 733
 734             unset($SESSION->completioncache[$this->course_id]);
 735         }
 736
 737         // Wipe course completion data too.
 738         $this->delete_course_completion_data();
 739     }
 740
 741     /**
 742      * Deletes completion state related to an activity for all users.
 743      *
 744      * Intended for use only when the activity itself is deleted.
 745      *
 746      * @global object
 747      * @global object
 748      * @param object $cm Activity
 749      */
 750     public function delete_all_state($cm) {
 751         global $SESSION, $DB;
 752
 753         // Delete from database
 754         $DB->delete_records('course_modules_completion', array('coursemoduleid'=>$cm->id));
 755
 756         // Erase cache data for current user if applicable
 757         if (isset($SESSION->completioncache) &&
 758             array_key_exists($cm->course, $SESSION->completioncache) &&
 759             array_key_exists($cm->id, $SESSION->completioncache[$cm->course])) {
 760
 761             unset($SESSION->completioncache[$cm->course][$cm->id]);
 762         }
 763
 764         // Check if there is an associated course completion criteria
 765         $criteria = $this->get_criteria(COMPLETION_CRITERIA_TYPE_ACTIVITY);
 766         $acriteria = false;
 767         foreach ($criteria as $criterion) {
 768             if ($criterion->moduleinstance == $cm->id) {
 769                 $acriteria = $criterion;
 770                 break;
 771     }
 772         }
 773
 774         if ($acriteria) {
 775             // Delete all criteria completions relating to this activity
 776             $DB->delete_records('course_completion_crit_compl', array('course' => $this->course_id, 'criteriaid' => $acriteria->id));
 777             $DB->delete_records('course_completions', array('course' => $this->course_id));
 778         }
 779     }
 780
 781     /**
 782      * Recalculates completion state related to an activity for all users.
 783      *
 784      * Intended for use if completion conditions change. (This should be avoided
 785      * as it may cause some things to become incomplete when they were previously
 786      * complete, with the effect - for example - of hiding a later activity that
 787      * was previously available.)
 788      *
 789      * Resetting state of manual tickbox has same result as deleting state for
 790      * it.
 791      *
 792      * @global object
 793      * @uses COMPLETION_TRACKING_MANUAL
 794      * @uses COMPLETION_UNKNOWN
 795      * @param object $cm Activity
 796      */
 797     public function reset_all_state($cm) {
 798         global $DB;
 799
 800         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 801             $this->delete_all_state($cm);
 802             return;
 803         }
 804         // Get current list of users with completion state
 805         $rs = $DB->get_recordset('course_modules_completion', array('coursemoduleid'=>$cm->id), '', 'userid');
 806         $keepusers = array();
 807         foreach ($rs as $rec) {
 808             $keepusers[] = $rec->userid;
 809         }
 810         $rs->close();
 811
 812         // Delete all existing state [also clears session cache for current user]
 813         $this->delete_all_state($cm);
 814
 815         // Merge this with list of planned users (according to roles)
 816         $trackedusers = $this->get_tracked_users();
 817         foreach ($trackedusers as $trackeduser) {
 818             $keepusers[] = $trackeduser->id;
 819         }
 820         $keepusers = array_unique($keepusers);
 821
 822         // Recalculate state for each kept user
 823         foreach ($keepusers as $keepuser) {
 824             $this->update_state($cm, COMPLETION_UNKNOWN, $keepuser);
 825         }
 826     }
 827
 828     /**
 829      * Obtains completion data for a particular activity and user (from the
 830      * session cache if available, or by SQL query)
 831      *
 832      * @global object
 833      * @global object
 834      * @global object
 835      * @global object
 836      * @uses COMPLETION_CACHE_EXPIRY
 837      * @param object $cm Activity; only required field is ->id
 838      * @param bool $wholecourse If true (default false) then, when necessary to
 839      *   fill the cache, retrieves information from the entire course not just for
 840      *   this one activity
 841      * @param int $userid User ID or 0 (default) for current user
 842      * @param array $modinfo Supply the value here - this is used for unit
 843      *   testing and so that it can be called recursively from within
 844      *   get_fast_modinfo. (Needs only list of all CMs with IDs.)
 845      *   Otherwise the method calls get_fast_modinfo itself.
 846      * @return object Completion data (record from course_modules_completion)
 847      */
 848     public function get_data($cm, $wholecourse=false, $userid=0, $modinfo=null) {
 849         global $USER, $CFG, $SESSION, $DB;
 850
 851         // Get user ID
 852         if (!$userid) {
 853             $userid = $USER->id;
 854         }
 855
 856         // Is this the current user?
 857         $currentuser = $userid==$USER->id;
 858
 859         if ($currentuser && is_object($SESSION)) {
 860             // Make sure cache is present and is for current user (loginas
 861             // changes this)
 862             if (!isset($SESSION->completioncache) || $SESSION->completioncacheuserid!=$USER->id) {
 863                 $SESSION->completioncache = array();
 864                 $SESSION->completioncacheuserid = $USER->id;
 865             }
 866             // Expire any old data from cache
 867             foreach ($SESSION->completioncache as $courseid=>$activities) {
 868                 if (empty($activities['updated']) || $activities['updated'] < time()-COMPLETION_CACHE_EXPIRY) {
 869                     unset($SESSION->completioncache[$courseid]);
 870                 }
 871             }
 872             // See if requested data is present, if so use cache to get it
 873             if (isset($SESSION->completioncache) &&
 874                 array_key_exists($this->course->id, $SESSION->completioncache) &&
 875                 array_key_exists($cm->id, $SESSION->completioncache[$this->course->id])) {
 876                 return $SESSION->completioncache[$this->course->id][$cm->id];
 877             }
 878         }
 879
 880         // Not there, get via SQL
 881         if ($currentuser && $wholecourse) {
 882             // Get whole course data for cache
 883             $alldatabycmc = $DB->get_records_sql("
 884     SELECT
 885         cmc.*
 886     FROM
 887         {course_modules} cm
 888         INNER JOIN {course_modules_completion} cmc ON cmc.coursemoduleid=cm.id
 889     WHERE
 890         cm.course=? AND cmc.userid=?", array($this->course->id, $userid));
 891
 892             // Reindex by cm id
 893             $alldata = array();
 894             if ($alldatabycmc) {
 895                 foreach ($alldatabycmc as $data) {
 896                     $alldata[$data->coursemoduleid] = $data;
 897                 }
 898             }
 899
 900             // Get the module info and build up condition info for each one
 901             if (empty($modinfo)) {
 902                 $modinfo = get_fast_modinfo($this->course, $userid);
 903             }
 904             foreach ($modinfo->cms as $othercm) {
 905                 if (array_key_exists($othercm->id, $alldata)) {
 906                     $data = $alldata[$othercm->id];
 907                 } else {
 908                     // Row not present counts as 'not complete'
 909                     $data = new StdClass;
 910                     $data->id              = 0;
 911                     $data->coursemoduleid  = $othercm->id;
 912                     $data->userid          = $userid;
 913                     $data->completionstate = 0;
 914                     $data->viewed          = 0;
 915                     $data->timemodified    = 0;
 916                 }
 917                 $SESSION->completioncache[$this->course->id][$othercm->id] = $data;
 918             }
 919             $SESSION->completioncache[$this->course->id]['updated'] = time();
 920
 921             if (!isset($SESSION->completioncache[$this->course->id][$cm->id])) {
 922                 $this->internal_systemerror("Unexpected error: course-module {$cm->id} could not be found on course {$this->course->id}");
 923             }
 924             return $SESSION->completioncache[$this->course->id][$cm->id];
 925
 926         } else {
 927             // Get single record
 928             $data = $DB->get_record('course_modules_completion', array('coursemoduleid'=>$cm->id, 'userid'=>$userid));
 929             if ($data == false) {
 930                 // Row not present counts as 'not complete'
 931                 $data = new StdClass;
 932                 $data->id              = 0;
 933                 $data->coursemoduleid  = $cm->id;
 934                 $data->userid          = $userid;
 935                 $data->completionstate = 0;
 936                 $data->viewed          = 0;
 937                 $data->timemodified    = 0;
 938             }
 939
 940             // Put in cache
 941             if ($currentuser) {
 942                 $SESSION->completioncache[$this->course->id][$cm->id] = $data;
 943                 // For single updates, only set date if it was empty before
 944                 if (empty($SESSION->completioncache[$this->course->id]['updated'])) {
 945                     $SESSION->completioncache[$this->course->id]['updated'] = time();
 946                 }
 947             }
 948         }
 949
 950         return $data;
 951     }
 952
 953     /**
 954      * Updates completion data for a particular coursemodule and user (user is
 955      * determined from $data).
 956      *
 957      * (Internal function. Not private, so we can unit-test it.)
 958      *
 959      * @global object
 960      * @global object
 961      * @global object
 962      * @param object $cm Activity
 963      * @param object $data Data about completion for that user
 964      */
 965     function internal_set_data($cm, $data) {
 966         global $USER, $SESSION, $DB;
 967
 968         $transaction = $DB->start_delegated_transaction();
 969         if (!$data->id) {
 970             // Check there isn't really a row
 971             $data->id = $DB->get_field('course_modules_completion', 'id',
 972                     array('coursemoduleid'=>$data->coursemoduleid, 'userid'=>$data->userid));
 973         }
 974         if (!$data->id) {
 975             // Didn't exist before, needs creating
 976             $data->id = $DB->insert_record('course_modules_completion', $data);
 977         } else {
 978             // Has real (nonzero) id meaning that a database row exists, update
 979             $DB->update_record('course_modules_completion', $data);
 980         }
 981         $transaction->allow_commit();
 982
 983         if ($data->userid == $USER->id) {
 984             $SESSION->completioncache[$cm->course][$cm->id] = $data;
 985             $reset = 'reset';
 986             get_fast_modinfo($reset);
 987         }
 988     }
 989
 990     /**
 991      * Obtains a list of activities for which completion is enabled on the
 992      * course. The list is ordered by the section order of those activities.
 993      *
 994      * @global object
 995      * @uses COMPLETION_TRACKING_NONE
 996      * @param array $modinfo For unit testing only, supply the value
 997      *   here. Otherwise the method calls get_fast_modinfo
 998      * @return array Array from $cmid => $cm of all activities with completion enabled,
 999      *   empty array if none
1000      */
1001     public function get_activities($modinfo=null) {
1002         global $DB;
1003
1004         // Obtain those activities which have completion turned on
1005         $withcompletion = $DB->get_records_select('course_modules', 'course='.$this->course->id.
1006           ' AND completion<>'.COMPLETION_TRACKING_NONE);
1007         if (!$withcompletion) {
1008             return array();
1009         }
1010
1011         // Use modinfo to get section order and also add in names
1012         if (empty($modinfo)) {
1013             $modinfo = get_fast_modinfo($this->course);
1014         }
1015         $result = array();
1016         foreach ($modinfo->sections as $sectioncms) {
1017             foreach ($sectioncms as $cmid) {
1018                 if (array_key_exists($cmid, $withcompletion)) {
1019                     $result[$cmid] = $withcompletion[$cmid];
1020                     $result[$cmid]->modname = $modinfo->cms[$cmid]->modname;
1021                     $result[$cmid]->name    = $modinfo->cms[$cmid]->name;
1022                 }
1023             }
1024         }
1025
1026         return $result;
1027     }
1028
1029
1030     /**
1031      * Checks to see if the userid supplied has a tracked role in
1032      * this course
1033      *
1034      * @param   $userid     User id
1035      * @return  bool
1036      */
1037     function is_tracked_user($userid) {
1038         global $DB;
1039
1040         $tracked = $this->generate_tracked_user_sql();
1041
1042         $sql  = "SELECT u.id ";
1043         $sql .= $tracked->sql;
1044         $sql .= ' AND u.id = :userid';
1045
1046         $params = $tracked->data;
1047         $params['userid'] = (int)$userid;
1048         return $DB->record_exists_sql($sql, $params);
1049     }
1050
1051
1052     /**
1053      * Return number of users whose progress is tracked in this course
1054      *
1055      * Optionally supply a search's where clause, or a group id
1056      *
1057      * @param   string  $where          Where clause sql
1058      * @param   array   $where_params   Where clause params
1059      * @param   int     $groupid    Group id
1060      * @return  int
1061      */
1062     function get_num_tracked_users($where = '', $where_params = array(), $groupid = 0) {
1063         global $DB;
1064
1065         $tracked = $this->generate_tracked_user_sql($groupid);
1066
1067         $sql  = "SELECT COUNT(u.id) ";
1068         $sql .= $tracked->sql;
1069
1070         if ($where) {
1071             $sql .= " AND $where";
1072         }
1073
1074         $params = array_merge($tracked->data, $where_params);
1075         return $DB->count_records_sql($sql, $params);
1076     }
1077
1078
1079     /**
1080      * Return array of users whose progress is tracked in this course
1081      *
1082      * Optionally supply a search's where caluse, group id, sorting, paging
1083      *
1084      * @param   string      $where          Where clause sql (optional)
1085      * @param   array       $where_params   Where clause params (optional)
1086      * @param   integer     $groupid    Group ID to restrict to (optional)
1087      * @param   string      $sort       Order by clause (optional)
1088      * @param   integer     $limitfrom  Result start (optional)
1089      * @param   integer     $limitnum   Result max size (optional)
1090      * @param context $extracontext If set, includes extra user information fields
1091      *   as appropriate to display for current user in this context
1092      * @return  array
1093      */
1094     function get_tracked_users($where = '', $where_params = array(), $groupid = 0,
1095              $sort = '', $limitfrom = '', $limitnum = '', context $extracontext = null) {
1096
1097         global $DB;
1098
1099         $tracked = $this->generate_tracked_user_sql($groupid);
1100         $params = $tracked->data;
1101
1102         $sql = "
1103             SELECT
1104                 u.id,
1105                 u.firstname,
1106                 u.lastname,
1107                 u.idnumber
1108         ";
1109         if ($extracontext) {
1110             $sql .= get_extra_user_fields_sql($extracontext, 'u', '', array('idnumber'));
1111         }
1112
1113         $sql .= $tracked->sql;
1114
1115         if ($where) {
1116             $sql .= " AND $where";
1117             $params = array_merge($params, $where_params);
1118         }
1119
1120         if ($sort) {
1121             $sql .= " ORDER BY $sort";
1122         }
1123
1124         $users = $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
1125         return $users ? $users : array(); // In case it returns false
1126     }
1127
1128
1129     /**
1130      * Generate the SQL for finding tracked users in this course
1131      *
1132      * Returns an object containing the sql fragment and an array of
1133      * bound data params.
1134      *
1135      * @param   integer $groupid
1136      * @return  object
1137      */
1138     function generate_tracked_user_sql($groupid = 0) {
1139         global $CFG;
1140
1141         $return = new stdClass();
1142         $return->sql = '';
1143         $return->data = array();
1144
1145         if (!empty($CFG->gradebookroles)) {
1146             $roles = ' AND ra.roleid IN ('.$CFG->gradebookroles.')';
1147         } else {
1148             // This causes it to default to everyone (if there is no student role)
1149             $roles = '';
1150         }
1151
1152         // Build context sql
1153         $context = get_context_instance(CONTEXT_COURSE, $this->course->id);
1154         $parentcontexts = substr($context->path, 1); // kill leading slash
1155         $parentcontexts = str_replace('/', ',', $parentcontexts);
1156         if ($parentcontexts !== '') {
1157             $parentcontexts = ' OR ra.contextid IN ('.$parentcontexts.' )';
1158         }
1159
1160         $groupjoin   = '';
1161         $groupselect = '';
1162         if ($groupid) {
1163             $groupjoin   = "JOIN {groups_members} gm
1164                               ON gm.userid = u.id";
1165             $groupselect = " AND gm.groupid = :groupid ";
1166
1167             $return->data['groupid'] = $groupid;
1168         }
1169
1170         $return->sql = "
1171             FROM
1172                 {user} u
1173             INNER JOIN
1174                 {role_assignments} ra
1175              ON ra.userid = u.id
1176             INNER JOIN
1177                 {role} r
1178              ON r.id = ra.roleid
1179             INNER JOIN
1180                 {user_enrolments} ue
1181              ON ue.userid = u.id
1182             INNER JOIN
1183                 {enrol} e
1184              ON e.id = ue.enrolid
1185             INNER JOIN
1186                 {course} c
1187              ON c.id = e.courseid
1188             $groupjoin
1189             WHERE
1190                 (ra.contextid = :contextid $parentcontexts)
1191             AND c.id = :courseid
1192             AND ue.status = 0
1193             AND e.status = 0
1194             AND ue.timestart < :now1
1195             AND (ue.timeend > :now2 OR ue.timeend = 0)
1196                 $groupselect
1197                 $roles
1198         ";
1199
1200         $now = time();
1201         $return->data['now1'] = $now;
1202         $return->data['now2'] = $now;
1203         $return->data['contextid'] = $context->id;
1204         $return->data['courseid'] = $this->course->id;
1205
1206         return $return;
1207     }
1208
1209     /**
1210      * Obtains progress information across a course for all users on that course, or
1211      * for all users in a specific group. Intended for use when displaying progress.
1212      *
1213      * This includes only users who, in course context, have one of the roles for
1214      * which progress is tracked (the gradebookroles admin option) and are enrolled in course.
1215      *
1216      * Users are included (in the first array) even if they do not have
1217      * completion progress for any course-module.
1218      *
1219      * @global object
1220      * @global object
1221      * @param bool $sortfirstname If true, sort by first name, otherwise sort by
1222      *   last name
1223      * @param string $where Where clause sql (optional)
1224      * @param array $where_params Where clause params (optional)
1225      * @param int $groupid Group ID or 0 (default)/false for all groups
1226      * @param int $pagesize Number of users to actually return (optional)
1227      * @param int $start User to start at if paging (optional)
1228      * @param context $extracontext If set, includes extra user information fields
1229      *   as appropriate to display for current user in this context
1230      * @return Object with ->total and ->start (same as $start) and ->users;
1231      *   an array of user objects (like mdl_user id, firstname, lastname)
1232      *   containing an additional ->progress array of coursemoduleid => completionstate
1233      */
1234     public function get_progress_all($where = '', $where_params = array(), $groupid = 0,
1235             $sort = '', $pagesize = '', $start = '', context $extracontext = null) {
1236         global $CFG, $DB;
1237
1238         // Get list of applicable users
1239         $users = $this->get_tracked_users($where, $where_params, $groupid, $sort,
1240                 $start, $pagesize, $extracontext);
1241
1242         // Get progress information for these users in groups of 1, 000 (if needed)
1243         // to avoid making the SQL IN too long
1244         $results = array();
1245         $userids = array();
1246         foreach ($users as $user) {
1247             $userids[] = $user->id;
1248             $results[$user->id] = $user;
1249             $results[$user->id]->progress = array();
1250         }
1251
1252         for($i=0; $i<count($userids); $i+=1000) {
1253             $blocksize = count($userids)-$i < 1000 ? count($userids)-$i : 1000;
1254
1255             list($insql, $params) = $DB->get_in_or_equal(array_slice($userids, $i, $blocksize));
1256             array_splice($params, 0, 0, array($this->course->id));
1257             $rs = $DB->get_recordset_sql("
1258                 SELECT
1259                     cmc.*
1260                 FROM
1261                     {course_modules} cm
1262                     INNER JOIN {course_modules_completion} cmc ON cm.id=cmc.coursemoduleid
1263                 WHERE
1264                     cm.course=? AND cmc.userid $insql
1265     ", $params);
1266             foreach ($rs as $progress) {
1267                 $progress = (object)$progress;
1268                 $results[$progress->userid]->progress[$progress->coursemoduleid] = $progress;
1269             }
1270             $rs->close();
1271         }
1272
1273         return $results;
1274     }
1275
1276     /**
1277      * Called by grade code to inform the completion system when a grade has
1278      * been changed. If the changed grade is used to determine completion for
1279      * the course-module, then the completion status will be updated.
1280      *
1281      * @uses COMPLETION_TRACKING_MANUAL
1282      * @uses COMPLETION_INCOMPLETE
1283      * @param object $cm Course-module for item that owns grade
1284      * @param grade_item $item Grade item
1285      * @param object $grade
1286      * @param bool $deleted
1287      * @return void
1288      */
1289     public function inform_grade_changed($cm, $item, $grade, $deleted) {
1290         // Bail out now if completion is not enabled for course-module, it is enabled
1291         // but is set to manual, grade is not used to compute completion, or this
1292         // is a different numbered grade
1293         if (!$this->is_enabled($cm) ||
1294             $cm->completion == COMPLETION_TRACKING_MANUAL ||
1295             is_null($cm->completiongradeitemnumber) ||
1296             $item->itemnumber != $cm->completiongradeitemnumber) {
1297             return;
1298         }
1299
1300         // What is the expected result based on this grade?
1301         if ($deleted) {
1302             // Grade being deleted, so only change could be to make it incomplete
1303             $possibleresult = COMPLETION_INCOMPLETE;
1304         } else {
1305             $possibleresult = $this->internal_get_grade_state($item, $grade);
1306         }
1307
1308         // OK, let's update state based on this
1309         $this->update_state($cm, $possibleresult, $grade->userid);
1310     }
1311
1312     /**
1313      * Calculates the completion state that would result from a graded item
1314      * (where grade-based completion is turned on) based on the actual grade
1315      * and settings.
1316      *
1317      * Internal function. Not private, so we can unit-test it.
1318      *
1319      * @uses COMPLETION_INCOMPLETE
1320      * @uses COMPLETION_COMPLETE_PASS
1321      * @uses COMPLETION_COMPLETE_FAIL
1322      * @uses COMPLETION_COMPLETE
1323      * @param object $item grade_item
1324      * @param object $grade grade_grade
1325      * @return int Completion state e.g. COMPLETION_INCOMPLETE
1326      */
1327     function internal_get_grade_state($item, $grade) {
1328         if (!$grade) {
1329             return COMPLETION_INCOMPLETE;
1330         }
1331         // Conditions to show pass/fail:
1332         // a) Grade has pass mark (default is 0.00000 which is boolean true so be careful)
1333         // b) Grade is visible (neither hidden nor hidden-until)
1334         if ($item->gradepass && $item->gradepass > 0.000009 && !$item->hidden) {
1335             // Use final grade if set otherwise raw grade
1336             $score = !is_null($grade->finalgrade) ? $grade->finalgrade : $grade->rawgrade;
1337
1338             // We are displaying and tracking pass/fail
1339             if ($score >= $item->gradepass) {
1340                 return COMPLETION_COMPLETE_PASS;
1341             } else {
1342                 return COMPLETION_COMPLETE_FAIL;
1343             }
1344         } else {
1345             // Not displaying pass/fail, so just if there is a grade
1346             if (!is_null($grade->finalgrade) || !is_null($grade->rawgrade)) {
1347                 // Grade exists, so maybe complete now
1348                 return COMPLETION_COMPLETE;
1349             } else {
1350                 // Grade does not exist, so maybe incomplete now
1351                 return COMPLETION_INCOMPLETE;
1352             }
1353         }
1354     }
1355
1356     /**
1357      * This is to be used only for system errors (things that shouldn't happen)
1358      * and not user-level errors.
1359      *
1360      * @global object
1361      * @param string $error Error string (will not be displayed to user unless
1362      *   debugging is enabled)
1363      * @return void Throws moodle_exception Exception with the error string as debug info
1364      */
1365     function internal_systemerror($error) {
1366         global $CFG;
1367         throw new moodle_exception('err_system','completion',
1368             $CFG->wwwroot.'/course/view.php?id='.$this->course->id,null,$error);
1369     }
1370
1371     /**
1372      * For testing only. Wipes information cached in user session.
1373      *
1374      * @global object
1375      */
1376     static function wipe_session_cache() {
1377         global $SESSION;
1378         unset($SESSION->completioncache);
1379         unset($SESSION->completioncacheuserid);
1380     }
1381 }