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