lib/completionlib.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  * Contains classes, functions and constants used during the tracking
  19  * of activity completion for users.
  20  *
  21  * Completion top-level options (admin setting enablecompletion)
  22  *
  23  * @package core_completion
  24  * @category completion
  25  * @copyright 1999 onwards Martin Dougiamas   {@link http://moodle.com}
  26  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  27  */
  28
  29 defined('MOODLE_INTERNAL') || die();
  30
  31 /**
  32  * Include the required completion libraries
  33  */
  34 require_once $CFG->dirroot.'/completion/completion_aggregation.php';
  35 require_once $CFG->dirroot.'/completion/criteria/completion_criteria.php';
  36 require_once $CFG->dirroot.'/completion/completion_completion.php';
  37 require_once $CFG->dirroot.'/completion/completion_criteria_completion.php';
  38
  39
  40 /**
  41  * The completion system is enabled in this site/course
  42  */
  43 define('COMPLETION_ENABLED', 1);
  44 /**
  45  * The completion system is not enabled in this site/course
  46  */
  47 define('COMPLETION_DISABLED', 0);
  48
  49 /**
  50  * Completion tracking is disabled for this activity
  51  * This is a completion tracking option per-activity  (course_modules/completion)
  52  */
  53 define('COMPLETION_TRACKING_NONE', 0);
  54
  55 /**
  56  * Manual completion tracking (user ticks box) is enabled for this activity
  57  * This is a completion tracking option per-activity  (course_modules/completion)
  58  */
  59 define('COMPLETION_TRACKING_MANUAL', 1);
  60 /**
  61  * Automatic completion tracking (system ticks box) is enabled for this activity
  62  * This is a completion tracking option per-activity  (course_modules/completion)
  63  */
  64 define('COMPLETION_TRACKING_AUTOMATIC', 2);
  65
  66 /**
  67  * The user has not completed this activity.
  68  * This is a completion state value (course_modules_completion/completionstate)
  69  */
  70 define('COMPLETION_INCOMPLETE', 0);
  71 /**
  72  * The user has completed this activity. It is not specified whether they have
  73  * passed or failed it.
  74  * This is a completion state value (course_modules_completion/completionstate)
  75  */
  76 define('COMPLETION_COMPLETE', 1);
  77 /**
  78  * The user has completed this activity with a grade above the pass mark.
  79  * This is a completion state value (course_modules_completion/completionstate)
  80  */
  81 define('COMPLETION_COMPLETE_PASS', 2);
  82 /**
  83  * The user has completed this activity but their grade is less than the pass mark
  84  * This is a completion state value (course_modules_completion/completionstate)
  85  */
  86 define('COMPLETION_COMPLETE_FAIL', 3);
  87
  88 /**
  89  * The effect of this change to completion status is unknown.
  90  * A completion effect changes (used only in update_state)
  91  */
  92 define('COMPLETION_UNKNOWN', -1);
  93 /**
  94  * The user's grade has changed, so their new state might be
  95  * COMPLETION_COMPLETE_PASS or COMPLETION_COMPLETE_FAIL.
  96  * A completion effect changes (used only in update_state)
  97  */
  98 define('COMPLETION_GRADECHANGE', -2);
  99
 100 /**
 101  * User must view this activity.
 102  * Whether view is required to create an activity (course_modules/completionview)
 103  */
 104 define('COMPLETION_VIEW_REQUIRED', 1);
 105 /**
 106  * User does not need to view this activity
 107  * Whether view is required to create an activity (course_modules/completionview)
 108  */
 109 define('COMPLETION_VIEW_NOT_REQUIRED', 0);
 110
 111 /**
 112  * User has viewed this activity.
 113  * Completion viewed state (course_modules_completion/viewed)
 114  */
 115 define('COMPLETION_VIEWED', 1);
 116 /**
 117  * User has not viewed this activity.
 118  * Completion viewed state (course_modules_completion/viewed)
 119  */
 120 define('COMPLETION_NOT_VIEWED', 0);
 121
 122 /**
 123  * Cache expiry time in seconds (10 minutes)
 124  * Completion cacheing
 125  */
 126 define('COMPLETION_CACHE_EXPIRY', 10*60);
 127
 128 /**
 129  * Completion details should be ORed together and you should return false if
 130  * none apply.
 131  */
 132 define('COMPLETION_OR', false);
 133 /**
 134  * Completion details should be ANDed together and you should return true if
 135  * none apply
 136  */
 137 define('COMPLETION_AND', true);
 138
 139 /**
 140  * Course completion criteria aggregation method.
 141  */
 142 define('COMPLETION_AGGREGATION_ALL', 1);
 143 /**
 144  * Course completion criteria aggregation method.
 145  */
 146 define('COMPLETION_AGGREGATION_ANY', 2);
 147
 148
 149 /**
 150  * Class represents completion information for a course.
 151  *
 152  * Does not contain any data, so you can safely construct it multiple times
 153  * without causing any problems.
 154  *
 155  * @package core
 156  * @category completion
 157  * @copyright 2008 Sam Marshall
 158  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 159  */
 160 class completion_info {
 161
 162     /* @var stdClass Course object passed during construction */
 163     private $course;
 164
 165     /* @var int Course id */
 166     public $course_id;
 167
 168     /* @var array Completion criteria {@link completion_info::get_criteria()}  */
 169     private $criteria;
 170
 171     /**
 172      * Return array of aggregation methods
 173      * @return array
 174      */
 175     public static function get_aggregation_methods() {
 176         return array(
 177             COMPLETION_AGGREGATION_ALL => get_string('all'),
 178             COMPLETION_AGGREGATION_ANY => get_string('any', 'completion'),
 179         );
 180     }
 181
 182     /**
 183      * Constructs with course details.
 184      *
 185      * When instantiating a new completion info object you must provide a course
 186      * object with at least id, and enablecompletion properties.
 187      *
 188      * @param stdClass $course Moodle course object.
 189      */
 190     public function __construct($course) {
 191         $this->course = $course;
 192         $this->course_id = $course->id;
 193     }
 194
 195     /**
 196      * Determines whether completion is enabled across entire site.
 197      *
 198      * @return bool COMPLETION_ENABLED (true) if completion is enabled for the site,
 199      *     COMPLETION_DISABLED (false) if it's complete
 200      */
 201     public static function is_enabled_for_site() {
 202         global $CFG;
 203         return !empty($CFG->enablecompletion);
 204     }
 205
 206     /**
 207      * Checks whether completion is enabled in a particular course and possibly
 208      * activity.
 209      *
 210      * @param stdClass|cm_info $cm Course-module object. If not specified, returns the course
 211      *   completion enable state.
 212      * @return mixed COMPLETION_ENABLED or COMPLETION_DISABLED (==0) in the case of
 213      *   site and course; COMPLETION_TRACKING_MANUAL, _AUTOMATIC or _NONE (==0)
 214      *   for a course-module.
 215      */
 216     public function is_enabled($cm = null) {
 217         global $CFG, $DB;
 218
 219         // First check global completion
 220         if (!isset($CFG->enablecompletion) || $CFG->enablecompletion == COMPLETION_DISABLED) {
 221             return COMPLETION_DISABLED;
 222         }
 223
 224         // Load data if we do not have enough
 225         if (!isset($this->course->enablecompletion)) {
 226             $this->course->enablecompletion = $DB->get_field('course', 'enablecompletion', array('id' => $this->course->id));
 227         }
 228
 229         // Check course completion
 230         if ($this->course->enablecompletion == COMPLETION_DISABLED) {
 231             return COMPLETION_DISABLED;
 232         }
 233
 234         // If there was no $cm and we got this far, then it's enabled
 235         if (!$cm) {
 236             return COMPLETION_ENABLED;
 237         }
 238
 239         // Return course-module completion value
 240         return $cm->completion;
 241     }
 242
 243     /**
 244      * Displays the 'Your progress' help icon, if completion tracking is enabled.
 245      * Just prints the result of display_help_icon().
 246      *
 247      * @deprecated since Moodle 2.0 - Use display_help_icon instead.
 248      */
 249     public function print_help_icon() {
 250         print $this->display_help_icon();
 251     }
 252
 253     /**
 254      * Returns the 'Your progress' help icon, if completion tracking is enabled.
 255      *
 256      * @return string HTML code for help icon, or blank if not needed
 257      */
 258     public function display_help_icon() {
 259         global $PAGE, $OUTPUT;
 260         $result = '';
 261         if ($this->is_enabled() && !$PAGE->user_is_editing() && isloggedin() && !isguestuser()) {
 262             $result .= html_writer::tag('div', get_string('yourprogress','completion') .
 263                     $OUTPUT->help_icon('completionicons', 'completion'), array('id' => 'completionprogressid',
 264                     'class' => 'completionprogress'));
 265         }
 266         return $result;
 267     }
 268
 269     /**
 270      * Get a course completion for a user
 271      *
 272      * @param int $user_id User id
 273      * @param int $criteriatype Specific criteria type to return
 274      * @return bool|completion_criteria_completion returns false on fail
 275      */
 276     public function get_completion($user_id, $criteriatype) {
 277         $completions = $this->get_completions($user_id, $criteriatype);
 278
 279         if (empty($completions)) {
 280             return false;
 281         } elseif (count($completions) > 1) {
 282             print_error('multipleselfcompletioncriteria', 'completion');
 283         }
 284
 285         return $completions[0];
 286     }
 287
 288     /**
 289      * Get all course criteria's completion objects for a user
 290      *
 291      * @param int $user_id User id
 292      * @param int $criteriatype Specific criteria type to return (optional)
 293      * @return array
 294      */
 295     public function get_completions($user_id, $criteriatype = null) {
 296         $criterion = $this->get_criteria($criteriatype);
 297
 298         $completions = array();
 299
 300         foreach ($criterion as $criteria) {
 301             $params = array(
 302                 'course'        => $this->course_id,
 303                 'userid'        => $user_id,
 304                 'criteriaid'    => $criteria->id
 305             );
 306
 307             $completion = new completion_criteria_completion($params);
 308             $completion->attach_criteria($criteria);
 309
 310             $completions[] = $completion;
 311         }
 312
 313         return $completions;
 314     }
 315
 316     /**
 317      * Get completion object for a user and a criteria
 318      *
 319      * @param int $user_id User id
 320      * @param completion_criteria $criteria Criteria object
 321      * @return completion_criteria_completion
 322      */
 323     public function get_user_completion($user_id, $criteria) {
 324         $params = array(
 325             'course'        => $this->course_id,
 326             'userid'        => $user_id,
 327             'criteriaid'    => $criteria->id,
 328         );
 329
 330         $completion = new completion_criteria_completion($params);
 331         return $completion;
 332     }
 333
 334     /**
 335      * Check if course has completion criteria set
 336      *
 337      * @return bool Returns true if there are criteria
 338      */
 339     public function has_criteria() {
 340         $criteria = $this->get_criteria();
 341
 342         return (bool) count($criteria);
 343     }
 344
 345     /**
 346      * Get course completion criteria
 347      *
 348      * @param int $criteriatype Specific criteria type to return (optional)
 349      */
 350     public function get_criteria($criteriatype = null) {
 351
 352         // Fill cache if empty
 353         if (!is_array($this->criteria)) {
 354             global $DB;
 355
 356             $params = array(
 357                 'course'    => $this->course->id
 358             );
 359
 360             // Load criteria from database
 361             $records = (array)$DB->get_records('course_completion_criteria', $params);
 362
 363             // Build array of criteria objects
 364             $this->criteria = array();
 365             foreach ($records as $record) {
 366                 $this->criteria[$record->id] = completion_criteria::factory((array)$record);
 367             }
 368         }
 369
 370         // If after all criteria
 371         if ($criteriatype === null) {
 372             return $this->criteria;
 373         }
 374
 375         // If we are only after a specific criteria type
 376         $criteria = array();
 377         foreach ($this->criteria as $criterion) {
 378
 379             if ($criterion->criteriatype != $criteriatype) {
 380                 continue;
 381             }
 382
 383             $criteria[$criterion->id] = $criterion;
 384         }
 385
 386         return $criteria;
 387     }
 388
 389     /**
 390      * Get aggregation method
 391      *
 392      * @param int $criteriatype If none supplied, get overall aggregation method (optional)
 393      * @return int One of COMPLETION_AGGREGATION_ALL or COMPLETION_AGGREGATION_ANY
 394      */
 395     public function get_aggregation_method($criteriatype = null) {
 396         $params = array(
 397             'course'        => $this->course_id,
 398             'criteriatype'  => $criteriatype
 399         );
 400
 401         $aggregation = new completion_aggregation($params);
 402
 403         if (!$aggregation->id) {
 404             $aggregation->method = COMPLETION_AGGREGATION_ALL;
 405         }
 406
 407         return $aggregation->method;
 408     }
 409
 410     /**
 411      * Get incomplete course completion criteria
 412      *
 413      * @return array
 414      */
 415     public function get_incomplete_criteria() {
 416         $incomplete = array();
 417
 418         foreach ($this->get_criteria() as $criteria) {
 419             if (!$criteria->is_complete()) {
 420                 $incomplete[] = $criteria;
 421             }
 422         }
 423
 424         return $incomplete;
 425     }
 426
 427     /**
 428      * Clear old course completion criteria
 429      */
 430     public function clear_criteria() {
 431         global $DB;
 432         $DB->delete_records('course_completion_criteria', array('course' => $this->course_id));
 433         $DB->delete_records('course_completion_aggr_methd', array('course' => $this->course_id));
 434
 435         $this->delete_course_completion_data();
 436     }
 437
 438     /**
 439      * Has the supplied user completed this course
 440      *
 441      * @param int $user_id User's id
 442      * @return boolean
 443      */
 444     public function is_course_complete($user_id) {
 445         $params = array(
 446             'userid'    => $user_id,
 447             'course'  => $this->course_id
 448         );
 449
 450         $ccompletion = new completion_completion($params);
 451         return $ccompletion->is_complete();
 452     }
 453
 454     /**
 455      * Updates (if necessary) the completion state of activity $cm for the given
 456      * user.
 457      *
 458      * For manual completion, this function is called when completion is toggled
 459      * with $possibleresult set to the target state.
 460      *
 461      * For automatic completion, this function should be called every time a module
 462      * does something which might influence a user's completion state. For example,
 463      * if a forum provides options for marking itself 'completed' once a user makes
 464      * N posts, this function should be called every time a user makes a new post.
 465      * [After the post has been saved to the database]. When calling, you do not
 466      * need to pass in the new completion state. Instead this function carries out
 467      * completion calculation by checking grades and viewed state itself, and
 468      * calling the involved module via modulename_get_completion_state() to check
 469      * module-specific conditions.
 470      *
 471      * @param stdClass|cm_info $cm Course-module
 472      * @param int $possibleresult Expected completion result. If the event that
 473      *   has just occurred (e.g. add post) can only result in making the activity
 474      *   complete when it wasn't before, use COMPLETION_COMPLETE. If the event that
 475      *   has just occurred (e.g. delete post) can only result in making the activity
 476      *   not complete when it was previously complete, use COMPLETION_INCOMPLETE.
 477      *   Otherwise use COMPLETION_UNKNOWN. Setting this value to something other than
 478      *   COMPLETION_UNKNOWN significantly improves performance because it will abandon
 479      *   processing early if the user's completion state already matches the expected
 480      *   result. For manual events, COMPLETION_COMPLETE or COMPLETION_INCOMPLETE
 481      *   must be used; these directly set the specified state.
 482      * @param int $userid User ID to be updated. Default 0 = current user
 483      * @return void
 484      */
 485     public function update_state($cm, $possibleresult=COMPLETION_UNKNOWN, $userid=0) {
 486         global $USER, $SESSION;
 487
 488         // Do nothing if completion is not enabled for that activity
 489         if (!$this->is_enabled($cm)) {
 490             return;
 491         }
 492
 493         // Get current value of completion state and do nothing if it's same as
 494         // the possible result of this change. If the change is to COMPLETE and the
 495         // current value is one of the COMPLETE_xx subtypes, ignore that as well
 496         $current = $this->get_data($cm, false, $userid);
 497         if ($possibleresult == $current->completionstate ||
 498             ($possibleresult == COMPLETION_COMPLETE &&
 499                 ($current->completionstate == COMPLETION_COMPLETE_PASS ||
 500                 $current->completionstate == COMPLETION_COMPLETE_FAIL))) {
 501             return;
 502         }
 503
 504         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 505             // For manual tracking we set the result directly
 506             switch($possibleresult) {
 507                 case COMPLETION_COMPLETE:
 508                 case COMPLETION_INCOMPLETE:
 509                     $newstate = $possibleresult;
 510                     break;
 511                 default:
 512                     $this->internal_systemerror("Unexpected manual completion state for {$cm->id}: $possibleresult");
 513             }
 514
 515         } else {
 516             // Automatic tracking; get new state
 517             $newstate = $this->internal_get_state($cm, $userid, $current);
 518         }
 519
 520         // If changed, update
 521         if ($newstate != $current->completionstate) {
 522             $current->completionstate = $newstate;
 523             $current->timemodified    = time();
 524             $this->internal_set_data($cm, $current);
 525         }
 526     }
 527
 528     /**
 529      * Calculates the completion state for an activity and user.
 530      *
 531      * Internal function. Not private, so we can unit-test it.
 532      *
 533      * @param stdClass|cm_info $cm Activity
 534      * @param int $userid ID of user
 535      * @param stdClass $current Previous completion information from database
 536      * @return mixed
 537      */
 538     public function internal_get_state($cm, $userid, $current) {
 539         global $USER, $DB, $CFG;
 540
 541         // Get user ID
 542         if (!$userid) {
 543             $userid = $USER->id;
 544         }
 545
 546         // Check viewed
 547         if ($cm->completionview == COMPLETION_VIEW_REQUIRED &&
 548             $current->viewed == COMPLETION_NOT_VIEWED) {
 549
 550             return COMPLETION_INCOMPLETE;
 551         }
 552
 553         // Modname hopefully is provided in $cm but just in case it isn't, let's grab it
 554         if (!isset($cm->modname)) {
 555             $cm->modname = $DB->get_field('modules', 'name', array('id'=>$cm->module));
 556         }
 557
 558         $newstate = COMPLETION_COMPLETE;
 559
 560         // Check grade
 561         if (!is_null($cm->completiongradeitemnumber)) {
 562             require_once($CFG->libdir.'/gradelib.php');
 563             $item = grade_item::fetch(array('courseid'=>$cm->course, 'itemtype'=>'mod',
 564                 'itemmodule'=>$cm->modname, 'iteminstance'=>$cm->instance,
 565                 'itemnumber'=>$cm->completiongradeitemnumber));
 566             if ($item) {
 567                 // Fetch 'grades' (will be one or none)
 568                 $grades = grade_grade::fetch_users_grades($item, array($userid), false);
 569                 if (empty($grades)) {
 570                     // No grade for user
 571                     return COMPLETION_INCOMPLETE;
 572                 }
 573                 if (count($grades) > 1) {
 574                     $this->internal_systemerror("Unexpected result: multiple grades for
 575                         item '{$item->id}', user '{$userid}'");
 576                 }
 577                 $newstate = self::internal_get_grade_state($item, reset($grades));
 578                 if ($newstate == COMPLETION_INCOMPLETE) {
 579                     return COMPLETION_INCOMPLETE;
 580                 }
 581
 582             } else {
 583                 $this->internal_systemerror("Cannot find grade item for '{$cm->modname}'
 584                     cm '{$cm->id}' matching number '{$cm->completiongradeitemnumber}'");
 585             }
 586         }
 587
 588         if (plugin_supports('mod', $cm->modname, FEATURE_COMPLETION_HAS_RULES)) {
 589             $function = $cm->modname.'_get_completion_state';
 590             if (!function_exists($function)) {
 591                 $this->internal_systemerror("Module {$cm->modname} claims to support
 592                     FEATURE_COMPLETION_HAS_RULES but does not have required
 593                     {$cm->modname}_get_completion_state function");
 594             }
 595             if (!$function($this->course, $cm, $userid, COMPLETION_AND)) {
 596                 return COMPLETION_INCOMPLETE;
 597             }
 598         }
 599
 600         return $newstate;
 601
 602     }
 603
 604     /**
 605      * Marks a module as viewed.
 606      *
 607      * Should be called whenever a module is 'viewed' (it is up to the module how to
 608      * determine that). Has no effect if viewing is not set as a completion condition.
 609      *
 610      * Note that this function must be called before you print the page header because
 611      * it is possible that the navigation block may depend on it. If you call it after
 612      * printing the header, it shows a developer debug warning.
 613      *
 614      * @param stdClass|cm_info $cm Activity
 615      * @param int $userid User ID or 0 (default) for current user
 616      * @return void
 617      */
 618     public function set_module_viewed($cm, $userid=0) {
 619         global $PAGE;
 620         if ($PAGE->headerprinted) {
 621             debugging('set_module_viewed must be called before header is printed',
 622                     DEBUG_DEVELOPER);
 623         }
 624
 625         // Don't do anything if view condition is not turned on
 626         if ($cm->completionview == COMPLETION_VIEW_NOT_REQUIRED || !$this->is_enabled($cm)) {
 627             return;
 628         }
 629
 630         // Get current completion state
 631         $data = $this->get_data($cm, false, $userid);
 632
 633         // If we already viewed it, don't do anything
 634         if ($data->viewed == COMPLETION_VIEWED) {
 635             return;
 636         }
 637
 638         // OK, change state, save it, and update completion
 639         $data->viewed = COMPLETION_VIEWED;
 640         $this->internal_set_data($cm, $data);
 641         $this->update_state($cm, COMPLETION_COMPLETE, $userid);
 642     }
 643
 644     /**
 645      * Determines how much completion data exists for an activity. This is used when
 646      * deciding whether completion information should be 'locked' in the module
 647      * editing form.
 648      *
 649      * @param cm_info $cm Activity
 650      * @return int The number of users who have completion data stored for this
 651      *   activity, 0 if none
 652      */
 653     public function count_user_data($cm) {
 654         global $DB;
 655
 656         return $DB->get_field_sql("
 657     SELECT
 658         COUNT(1)
 659     FROM
 660         {course_modules_completion}
 661     WHERE
 662         coursemoduleid=? AND completionstate<>0", array($cm->id));
 663     }
 664
 665     /**
 666      * Determines how much course completion data exists for a course. This is used when
 667      * deciding whether completion information should be 'locked' in the completion
 668      * settings form and activity completion settings.
 669      *
 670      * @param int $user_id Optionally only get course completion data for a single user
 671      * @return int The number of users who have completion data stored for this
 672      *     course, 0 if none
 673      */
 674     public function count_course_user_data($user_id = null) {
 675         global $DB;
 676
 677         $sql = '
 678     SELECT
 679         COUNT(1)
 680     FROM
 681         {course_completion_crit_compl}
 682     WHERE
 683         course = ?
 684         ';
 685
 686         $params = array($this->course_id);
 687
 688         // Limit data to a single user if an ID is supplied
 689         if ($user_id) {
 690             $sql .= ' AND userid = ?';
 691             $params[] = $user_id;
 692         }
 693
 694         return $DB->get_field_sql($sql, $params);
 695     }
 696
 697     /**
 698      * Check if this course's completion criteria should be locked
 699      *
 700      * @return boolean
 701      */
 702     public function is_course_locked() {
 703         return (bool) $this->count_course_user_data();
 704     }
 705
 706     /**
 707      * Deletes all course completion completion data.
 708      *
 709      * Intended to be used when unlocking completion criteria settings.
 710      */
 711     public function delete_course_completion_data() {
 712         global $DB;
 713
 714         $DB->delete_records('course_completions', array('course' => $this->course_id));
 715         $DB->delete_records('course_completion_crit_compl', array('course' => $this->course_id));
 716     }
 717
 718     /**
 719      * Deletes all activity and course completion data for an entire course
 720      * (the below delete_all_state function does this for a single activity).
 721      *
 722      * Used by course reset page.
 723      */
 724     public function delete_all_completion_data() {
 725         global $DB, $SESSION;
 726
 727         // Delete from database.
 728         $DB->delete_records_select('course_modules_completion',
 729                 'coursemoduleid IN (SELECT id FROM {course_modules} WHERE course=?)',
 730                 array($this->course_id));
 731
 732         // Reset cache for current user.
 733         if (isset($SESSION->completioncache) &&
 734             array_key_exists($this->course_id, $SESSION->completioncache)) {
 735
 736             unset($SESSION->completioncache[$this->course_id]);
 737         }
 738
 739         // Wipe course completion data too.
 740         $this->delete_course_completion_data();
 741     }
 742
 743     /**
 744      * Deletes completion state related to an activity for all users.
 745      *
 746      * Intended for use only when the activity itself is deleted.
 747      *
 748      * @param stdClass|cm_info $cm Activity
 749      */
 750     public function delete_all_state($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      * @param stcClass|cm_info $cm Activity
 793      */
 794     public function reset_all_state($cm) {
 795         global $DB;
 796
 797         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 798             $this->delete_all_state($cm);
 799             return;
 800         }
 801         // Get current list of users with completion state
 802         $rs = $DB->get_recordset('course_modules_completion', array('coursemoduleid'=>$cm->id), '', 'userid');
 803         $keepusers = array();
 804         foreach ($rs as $rec) {
 805             $keepusers[] = $rec->userid;
 806         }
 807         $rs->close();
 808
 809         // Delete all existing state [also clears session cache for current user]
 810         $this->delete_all_state($cm);
 811
 812         // Merge this with list of planned users (according to roles)
 813         $trackedusers = $this->get_tracked_users();
 814         foreach ($trackedusers as $trackeduser) {
 815             $keepusers[] = $trackeduser->id;
 816         }
 817         $keepusers = array_unique($keepusers);
 818
 819         // Recalculate state for each kept user
 820         foreach ($keepusers as $keepuser) {
 821             $this->update_state($cm, COMPLETION_UNKNOWN, $keepuser);
 822         }
 823     }
 824
 825     /**
 826      * Obtains completion data for a particular activity and user (from the
 827      * session cache if available, or by SQL query)
 828      *
 829      * @param stcClass|cm_info $cm Activity; only required field is ->id
 830      * @param bool $wholecourse If true (default false) then, when necessary to
 831      *   fill the cache, retrieves information from the entire course not just for
 832      *   this one activity
 833      * @param int $userid User ID or 0 (default) for current user
 834      * @param array $modinfo Supply the value here - this is used for unit
 835      *   testing and so that it can be called recursively from within
 836      *   get_fast_modinfo. (Needs only list of all CMs with IDs.)
 837      *   Otherwise the method calls get_fast_modinfo itself.
 838      * @return object Completion data (record from course_modules_completion)
 839      */
 840     public function get_data($cm, $wholecourse = false, $userid = 0, $modinfo = null) {
 841         global $USER, $CFG, $SESSION, $DB;
 842
 843         // Get user ID
 844         if (!$userid) {
 845             $userid = $USER->id;
 846         }
 847
 848         // Is this the current user?
 849         $currentuser = $userid==$USER->id;
 850
 851         if ($currentuser && is_object($SESSION)) {
 852             // Make sure cache is present and is for current user (loginas
 853             // changes this)
 854             if (!isset($SESSION->completioncache) || $SESSION->completioncacheuserid!=$USER->id) {
 855                 $SESSION->completioncache = array();
 856                 $SESSION->completioncacheuserid = $USER->id;
 857             }
 858             // Expire any old data from cache
 859             foreach ($SESSION->completioncache as $courseid=>$activities) {
 860                 if (empty($activities['updated']) || $activities['updated'] < time()-COMPLETION_CACHE_EXPIRY) {
 861                     unset($SESSION->completioncache[$courseid]);
 862                 }
 863             }
 864             // See if requested data is present, if so use cache to get it
 865             if (isset($SESSION->completioncache) &&
 866                 array_key_exists($this->course->id, $SESSION->completioncache) &&
 867                 array_key_exists($cm->id, $SESSION->completioncache[$this->course->id])) {
 868                 return $SESSION->completioncache[$this->course->id][$cm->id];
 869             }
 870         }
 871
 872         // Not there, get via SQL
 873         if ($currentuser && $wholecourse) {
 874             // Get whole course data for cache
 875             $alldatabycmc = $DB->get_records_sql("
 876     SELECT
 877         cmc.*
 878     FROM
 879         {course_modules} cm
 880         INNER JOIN {course_modules_completion} cmc ON cmc.coursemoduleid=cm.id
 881     WHERE
 882         cm.course=? AND cmc.userid=?", array($this->course->id, $userid));
 883
 884             // Reindex by cm id
 885             $alldata = array();
 886             if ($alldatabycmc) {
 887                 foreach ($alldatabycmc as $data) {
 888                     $alldata[$data->coursemoduleid] = $data;
 889                 }
 890             }
 891
 892             // Get the module info and build up condition info for each one
 893             if (empty($modinfo)) {
 894                 $modinfo = get_fast_modinfo($this->course, $userid);
 895             }
 896             foreach ($modinfo->cms as $othercm) {
 897                 if (array_key_exists($othercm->id, $alldata)) {
 898                     $data = $alldata[$othercm->id];
 899                 } else {
 900                     // Row not present counts as 'not complete'
 901                     $data = new StdClass;
 902                     $data->id              = 0;
 903                     $data->coursemoduleid  = $othercm->id;
 904                     $data->userid          = $userid;
 905                     $data->completionstate = 0;
 906                     $data->viewed          = 0;
 907                     $data->timemodified    = 0;
 908                 }
 909                 $SESSION->completioncache[$this->course->id][$othercm->id] = $data;
 910             }
 911             $SESSION->completioncache[$this->course->id]['updated'] = time();
 912
 913             if (!isset($SESSION->completioncache[$this->course->id][$cm->id])) {
 914                 $this->internal_systemerror("Unexpected error: course-module {$cm->id} could not be found on course {$this->course->id}");
 915             }
 916             return $SESSION->completioncache[$this->course->id][$cm->id];
 917
 918         } else {
 919             // Get single record
 920             $data = $DB->get_record('course_modules_completion', array('coursemoduleid'=>$cm->id, 'userid'=>$userid));
 921             if ($data == false) {
 922                 // Row not present counts as 'not complete'
 923                 $data = new StdClass;
 924                 $data->id              = 0;
 925                 $data->coursemoduleid  = $cm->id;
 926                 $data->userid          = $userid;
 927                 $data->completionstate = 0;
 928                 $data->viewed          = 0;
 929                 $data->timemodified    = 0;
 930             }
 931
 932             // Put in cache
 933             if ($currentuser) {
 934                 $SESSION->completioncache[$this->course->id][$cm->id] = $data;
 935                 // For single updates, only set date if it was empty before
 936                 if (empty($SESSION->completioncache[$this->course->id]['updated'])) {
 937                     $SESSION->completioncache[$this->course->id]['updated'] = time();
 938                 }
 939             }
 940         }
 941
 942         return $data;
 943     }
 944
 945     /**
 946      * Updates completion data for a particular coursemodule and user (user is
 947      * determined from $data).
 948      *
 949      * (Internal function. Not private, so we can unit-test it.)
 950      *
 951      * @param stdClass|cm_info $cm Activity
 952      * @param stdClass $data Data about completion for that user
 953      */
 954     public function internal_set_data($cm, $data) {
 955         global $USER, $SESSION, $DB;
 956
 957         $transaction = $DB->start_delegated_transaction();
 958         if (!$data->id) {
 959             // Check there isn't really a row
 960             $data->id = $DB->get_field('course_modules_completion', 'id',
 961                     array('coursemoduleid'=>$data->coursemoduleid, 'userid'=>$data->userid));
 962         }
 963         if (!$data->id) {
 964             // Didn't exist before, needs creating
 965             $data->id = $DB->insert_record('course_modules_completion', $data);
 966         } else {
 967             // Has real (nonzero) id meaning that a database row exists, update
 968             $DB->update_record('course_modules_completion', $data);
 969         }
 970         $transaction->allow_commit();
 971
 972         if ($data->userid == $USER->id) {
 973             $SESSION->completioncache[$cm->course][$cm->id] = $data;
 974             // reset modinfo for user (no need to call rebuild_course_cache())
 975             get_fast_modinfo($cm->course, 0, true);
 976         }
 977     }
 978
 979     /**
 980      * Obtains a list of activities for which completion is enabled on the
 981      * course. The list is ordered by the section order of those activities.
 982      *
 983      * @param array $modinfo For unit testing only, supply the value
 984      *   here. Otherwise the method calls get_fast_modinfo
 985      * @return array Array from $cmid => $cm of all activities with completion enabled,
 986      *   empty array if none
 987      */
 988     public function get_activities($modinfo=null) {
 989         global $DB;
 990
 991         // Obtain those activities which have completion turned on
 992         $withcompletion = $DB->get_records_select('course_modules', 'course='.$this->course->id.
 993           ' AND completion<>'.COMPLETION_TRACKING_NONE);
 994         if (!$withcompletion) {
 995             return array();
 996         }
 997
 998         // Use modinfo to get section order and also add in names
 999         if (empty($modinfo)) {
1000             $modinfo = get_fast_modinfo($this->course);
1001         }
1002         $result = array();
1003         foreach ($modinfo->sections as $sectioncms) {
1004             foreach ($sectioncms as $cmid) {
1005                 if (array_key_exists($cmid, $withcompletion)) {
1006                     $result[$cmid] = $withcompletion[$cmid];
1007                     $result[$cmid]->modname = $modinfo->cms[$cmid]->modname;
1008                     $result[$cmid]->name    = $modinfo->cms[$cmid]->name;
1009                 }
1010             }
1011         }
1012
1013         return $result;
1014     }
1015
1016     /**
1017      * Checks to see if the userid supplied has a tracked role in
1018      * this course
1019      *
1020      * @param int $userid User id
1021      * @return bool
1022      */
1023     public function is_tracked_user($userid) {
1024         return is_enrolled(context_course::instance($this->course->id), $userid, '', true);
1025     }
1026
1027     /**
1028      * Returns the number of users whose progress is tracked in this course.
1029      *
1030      * Optionally supply a search's where clause, or a group id.
1031      *
1032      * @param string $where Where clause sql (use 'u.whatever' for user table fields)
1033      * @param array $whereparams Where clause params
1034      * @param int $groupid Group id
1035      * @return int Number of tracked users
1036      */
1037     public function get_num_tracked_users($where = '', $whereparams = array(), $groupid = 0) {
1038         global $DB;
1039
1040         list($enrolledsql, $enrolledparams) = get_enrolled_sql(
1041                 context_course::instance($this->course->id), '', $groupid, true);
1042         $sql  = 'SELECT COUNT(eu.id) FROM (' . $enrolledsql . ') eu JOIN {user} u ON u.id = eu.id';
1043         if ($where) {
1044             $sql .= " WHERE $where";
1045         }
1046
1047         $params = array_merge($enrolledparams, $whereparams);
1048         return $DB->count_records_sql($sql, $params);
1049     }
1050
1051     /**
1052      * Return array of users whose progress is tracked in this course.
1053      *
1054      * Optionally supply a search's where clause, group id, sorting, paging.
1055      *
1056      * @param string $where Where clause sql, referring to 'u.' fields (optional)
1057      * @param array $whereparams Where clause params (optional)
1058      * @param int $groupid Group ID to restrict to (optional)
1059      * @param string $sort Order by clause (optional)
1060      * @param int $limitfrom Result start (optional)
1061      * @param int $limitnum Result max size (optional)
1062      * @param context $extracontext If set, includes extra user information fields
1063      *   as appropriate to display for current user in this context
1064      * @return array Array of user objects with standard user fields
1065      */
1066     public function get_tracked_users($where = '', $whereparams = array(), $groupid = 0,
1067              $sort = '', $limitfrom = '', $limitnum = '', context $extracontext = null) {
1068
1069         global $DB;
1070
1071         list($enrolledsql, $params) = get_enrolled_sql(
1072                 context_course::instance($this->course->id),
1073                 'moodle/course:isincompletionreports', $groupid, true);
1074
1075         $sql = 'SELECT u.id, u.firstname, u.lastname, u.idnumber';
1076         if ($extracontext) {
1077             $sql .= get_extra_user_fields_sql($extracontext, 'u', '', array('idnumber'));
1078         }
1079         $sql .= ' FROM (' . $enrolledsql . ') eu JOIN {user} u ON u.id = eu.id';
1080
1081         if ($where) {
1082             $sql .= " AND $where";
1083             $params = array_merge($params, $whereparams);
1084         }
1085
1086         if ($sort) {
1087             $sql .= " ORDER BY $sort";
1088         }
1089
1090         return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
1091     }
1092
1093     /**
1094      * Obtains progress information across a course for all users on that course, or
1095      * for all users in a specific group. Intended for use when displaying progress.
1096      *
1097      * This includes only users who, in course context, have one of the roles for
1098      * which progress is tracked (the gradebookroles admin option) and are enrolled in course.
1099      *
1100      * Users are included (in the first array) even if they do not have
1101      * completion progress for any course-module.
1102      *
1103      * @param bool $sortfirstname If true, sort by first name, otherwise sort by
1104      *   last name
1105      * @param string $where Where clause sql (optional)
1106      * @param array $where_params Where clause params (optional)
1107      * @param int $groupid Group ID or 0 (default)/false for all groups
1108      * @param int $pagesize Number of users to actually return (optional)
1109      * @param int $start User to start at if paging (optional)
1110      * @param context $extracontext If set, includes extra user information fields
1111      *   as appropriate to display for current user in this context
1112      * @return stdClass with ->total and ->start (same as $start) and ->users;
1113      *   an array of user objects (like mdl_user id, firstname, lastname)
1114      *   containing an additional ->progress array of coursemoduleid => completionstate
1115      */
1116     public function get_progress_all($where = '', $where_params = array(), $groupid = 0,
1117             $sort = '', $pagesize = '', $start = '', context $extracontext = null) {
1118         global $CFG, $DB;
1119
1120         // Get list of applicable users
1121         $users = $this->get_tracked_users($where, $where_params, $groupid, $sort,
1122                 $start, $pagesize, $extracontext);
1123
1124         // Get progress information for these users in groups of 1, 000 (if needed)
1125         // to avoid making the SQL IN too long
1126         $results = array();
1127         $userids = array();
1128         foreach ($users as $user) {
1129             $userids[] = $user->id;
1130             $results[$user->id] = $user;
1131             $results[$user->id]->progress = array();
1132         }
1133
1134         for($i=0; $i<count($userids); $i+=1000) {
1135             $blocksize = count($userids)-$i < 1000 ? count($userids)-$i : 1000;
1136
1137             list($insql, $params) = $DB->get_in_or_equal(array_slice($userids, $i, $blocksize));
1138             array_splice($params, 0, 0, array($this->course->id));
1139             $rs = $DB->get_recordset_sql("
1140                 SELECT
1141                     cmc.*
1142                 FROM
1143                     {course_modules} cm
1144                     INNER JOIN {course_modules_completion} cmc ON cm.id=cmc.coursemoduleid
1145                 WHERE
1146                     cm.course=? AND cmc.userid $insql", $params);
1147             foreach ($rs as $progress) {
1148                 $progress = (object)$progress;
1149                 $results[$progress->userid]->progress[$progress->coursemoduleid] = $progress;
1150             }
1151             $rs->close();
1152         }
1153
1154         return $results;
1155     }
1156
1157     /**
1158      * Called by grade code to inform the completion system when a grade has
1159      * been changed. If the changed grade is used to determine completion for
1160      * the course-module, then the completion status will be updated.
1161      *
1162      * @param stdClass|cm_info $cm Course-module for item that owns grade
1163      * @param grade_item $item Grade item
1164      * @param stdClass $grade
1165      * @param bool $deleted
1166      */
1167     public function inform_grade_changed($cm, $item, $grade, $deleted) {
1168         // Bail out now if completion is not enabled for course-module, it is enabled
1169         // but is set to manual, grade is not used to compute completion, or this
1170         // is a different numbered grade
1171         if (!$this->is_enabled($cm) ||
1172             $cm->completion == COMPLETION_TRACKING_MANUAL ||
1173             is_null($cm->completiongradeitemnumber) ||
1174             $item->itemnumber != $cm->completiongradeitemnumber) {
1175             return;
1176         }
1177
1178         // What is the expected result based on this grade?
1179         if ($deleted) {
1180             // Grade being deleted, so only change could be to make it incomplete
1181             $possibleresult = COMPLETION_INCOMPLETE;
1182         } else {
1183             $possibleresult = self::internal_get_grade_state($item, $grade);
1184         }
1185
1186         // OK, let's update state based on this
1187         $this->update_state($cm, $possibleresult, $grade->userid);
1188     }
1189
1190     /**
1191      * Calculates the completion state that would result from a graded item
1192      * (where grade-based completion is turned on) based on the actual grade
1193      * and settings.
1194      *
1195      * Internal function. Not private, so we can unit-test it.
1196      *
1197      * @param grade_item $item an instance of grade_item
1198      * @param grade_grade $grade an instance of grade_grade
1199      * @return int Completion state e.g. COMPLETION_INCOMPLETE
1200      */
1201     public static function internal_get_grade_state($item, $grade) {
1202         if (!$grade) {
1203             return COMPLETION_INCOMPLETE;
1204         }
1205         // Conditions to show pass/fail:
1206         // a) Grade has pass mark (default is 0.00000 which is boolean true so be careful)
1207         // b) Grade is visible (neither hidden nor hidden-until)
1208         if ($item->gradepass && $item->gradepass > 0.000009 && !$item->hidden) {
1209             // Use final grade if set otherwise raw grade
1210             $score = !is_null($grade->finalgrade) ? $grade->finalgrade : $grade->rawgrade;
1211
1212             // We are displaying and tracking pass/fail
1213             if ($score >= $item->gradepass) {
1214                 return COMPLETION_COMPLETE_PASS;
1215             } else {
1216                 return COMPLETION_COMPLETE_FAIL;
1217             }
1218         } else {
1219             // Not displaying pass/fail, so just if there is a grade
1220             if (!is_null($grade->finalgrade) || !is_null($grade->rawgrade)) {
1221                 // Grade exists, so maybe complete now
1222                 return COMPLETION_COMPLETE;
1223             } else {
1224                 // Grade does not exist, so maybe incomplete now
1225                 return COMPLETION_INCOMPLETE;
1226             }
1227         }
1228     }
1229
1230     /**
1231      * Aggregate activity completion state
1232      *
1233      * @param   int     $type   Aggregation type (COMPLETION_* constant)
1234      * @param   bool    $old    Old state
1235      * @param   bool    $new    New state
1236      * @return  bool
1237      */
1238     public static function aggregate_completion_states($type, $old, $new) {
1239         if ($type == COMPLETION_AND) {
1240             return $old && $new;
1241         } else {
1242             return $old || $new;
1243         }
1244     }
1245
1246     /**
1247      * This is to be used only for system errors (things that shouldn't happen)
1248      * and not user-level errors.
1249      *
1250      * @global type $CFG
1251      * @param string $error Error string (will not be displayed to user unless debugging is enabled)
1252      * @throws moodle_exception Exception with the error string as debug info
1253      */
1254     public function internal_systemerror($error) {
1255         global $CFG;
1256         throw new moodle_exception('err_system','completion',
1257             $CFG->wwwroot.'/course/view.php?id='.$this->course->id,null,$error);
1258     }
1259
1260     /**
1261      * For testing only. Wipes information cached in user session.
1262      */
1263     public static function wipe_session_cache() {
1264         global $SESSION;
1265         unset($SESSION->completioncache);
1266         unset($SESSION->completioncacheuserid);
1267     }
1268 }