lib/completionlib.php

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