lib/completionlib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Contains classes, functions and constants used during the tracking
  19  * of activity completion for users.
  20  *
  21  * Completion top-level options (admin setting enablecompletion)
  22  *
  23  * @package core_completion
  24  * @category completion
  25  * @copyright 1999 onwards Martin Dougiamas   {@link http://moodle.com}
  26  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  27  */
  28
  29 defined('MOODLE_INTERNAL') || die();
  30
  31 /**
  32  * Include the required completion libraries
  33  */
  34 require_once $CFG->dirroot.'/completion/completion_aggregation.php';
  35 require_once $CFG->dirroot.'/completion/criteria/completion_criteria.php';
  36 require_once $CFG->dirroot.'/completion/completion_completion.php';
  37 require_once $CFG->dirroot.'/completion/completion_criteria_completion.php';
  38
  39
  40 /**
  41  * The completion system is enabled in this site/course
  42  */
  43 define('COMPLETION_ENABLED', 1);
  44 /**
  45  * The completion system is not enabled in this site/course
  46  */
  47 define('COMPLETION_DISABLED', 0);
  48
  49 /**
  50  * Completion tracking is disabled for this activity
  51  * This is a completion tracking option per-activity  (course_modules/completion)
  52  */
  53 define('COMPLETION_TRACKING_NONE', 0);
  54
  55 /**
  56  * Manual completion tracking (user ticks box) is enabled for this activity
  57  * This is a completion tracking option per-activity  (course_modules/completion)
  58  */
  59 define('COMPLETION_TRACKING_MANUAL', 1);
  60 /**
  61  * Automatic completion tracking (system ticks box) is enabled for this activity
  62  * This is a completion tracking option per-activity  (course_modules/completion)
  63  */
  64 define('COMPLETION_TRACKING_AUTOMATIC', 2);
  65
  66 /**
  67  * The user has not completed this activity.
  68  * This is a completion state value (course_modules_completion/completionstate)
  69  */
  70 define('COMPLETION_INCOMPLETE', 0);
  71 /**
  72  * The user has completed this activity. It is not specified whether they have
  73  * passed or failed it.
  74  * This is a completion state value (course_modules_completion/completionstate)
  75  */
  76 define('COMPLETION_COMPLETE', 1);
  77 /**
  78  * The user has completed this activity with a grade above the pass mark.
  79  * This is a completion state value (course_modules_completion/completionstate)
  80  */
  81 define('COMPLETION_COMPLETE_PASS', 2);
  82 /**
  83  * The user has completed this activity but their grade is less than the pass mark
  84  * This is a completion state value (course_modules_completion/completionstate)
  85  */
  86 define('COMPLETION_COMPLETE_FAIL', 3);
  87
  88 /**
  89  * The effect of this change to completion status is unknown.
  90  * A completion effect changes (used only in update_state)
  91  */
  92 define('COMPLETION_UNKNOWN', -1);
  93 /**
  94  * The user's grade has changed, so their new state might be
  95  * COMPLETION_COMPLETE_PASS or COMPLETION_COMPLETE_FAIL.
  96  * A completion effect changes (used only in update_state)
  97  */
  98 define('COMPLETION_GRADECHANGE', -2);
  99
 100 /**
 101  * User must view this activity.
 102  * Whether view is required to create an activity (course_modules/completionview)
 103  */
 104 define('COMPLETION_VIEW_REQUIRED', 1);
 105 /**
 106  * User does not need to view this activity
 107  * Whether view is required to create an activity (course_modules/completionview)
 108  */
 109 define('COMPLETION_VIEW_NOT_REQUIRED', 0);
 110
 111 /**
 112  * User has viewed this activity.
 113  * Completion viewed state (course_modules_completion/viewed)
 114  */
 115 define('COMPLETION_VIEWED', 1);
 116 /**
 117  * User has not viewed this activity.
 118  * Completion viewed state (course_modules_completion/viewed)
 119  */
 120 define('COMPLETION_NOT_VIEWED', 0);
 121
 122 /**
 123  * Cache expiry time in seconds (10 minutes)
 124  * Completion cacheing
 125  */
 126 define('COMPLETION_CACHE_EXPIRY', 10*60);
 127
 128 /**
 129  * Completion details should be ORed together and you should return false if
 130  * none apply.
 131  */
 132 define('COMPLETION_OR', false);
 133 /**
 134  * Completion details should be ANDed together and you should return true if
 135  * none apply
 136  */
 137 define('COMPLETION_AND', true);
 138
 139 /**
 140  * Course completion criteria aggregation method.
 141  */
 142 define('COMPLETION_AGGREGATION_ALL', 1);
 143 /**
 144  * Course completion criteria aggregation method.
 145  */
 146 define('COMPLETION_AGGREGATION_ANY', 2);
 147
 148
 149 /**
 150  * Utility function for checking if the logged in user can view
 151  * another's completion data for a particular course
 152  *
 153  * @access  public
 154  * @param   int         $userid     Completion data's owner
 155  * @param   mixed       $course     Course object or Course ID (optional)
 156  * @return  boolean
 157  */
 158 function completion_can_view_data($userid, $course = null) {
 159     global $USER;
 160
 161     if (!isloggedin()) {
 162         return false;
 163     }
 164
 165     if (!is_object($course)) {
 166         $cid = $course;
 167         $course = new object();
 168         $course->id = $cid;
 169     }
 170
 171     // Check if this is the site course
 172     if ($course->id == SITEID) {
 173         $course = null;
 174     }
 175
 176     // Check if completion is enabled
 177     if ($course) {
 178         $cinfo = new completion_info($course);
 179         if (!$cinfo->is_enabled()) {
 180             return false;
 181         }
 182     } else {
 183         if (!completion_info::is_enabled_for_site()) {
 184             return false;
 185         }
 186     }
 187
 188     // Is own user's data?
 189     if ($USER->id == $userid) {
 190         return true;
 191     }
 192
 193     // Check capabilities
 194     $personalcontext = context_user::instance($userid);
 195
 196     if (has_capability('moodle/user:viewuseractivitiesreport', $personalcontext)) {
 197         return true;
 198     } elseif (has_capability('report/completion:view', $personalcontext)) {
 199         return true;
 200     }
 201
 202     if ($course->id) {
 203         $coursecontext = context_course::instance($course->id);
 204     } else {
 205         $coursecontext = context_system::instance();
 206     }
 207
 208     if (has_capability('report/completion:view', $coursecontext)) {
 209         return true;
 210     }
 211
 212     return false;
 213 }
 214
 215
 216 /**
 217  * Class represents completion information for a course.
 218  *
 219  * Does not contain any data, so you can safely construct it multiple times
 220  * without causing any problems.
 221  *
 222  * @package core
 223  * @category completion
 224  * @copyright 2008 Sam Marshall
 225  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 226  */
 227 class completion_info {
 228
 229     /* @var stdClass Course object passed during construction */
 230     private $course;
 231
 232     /* @var int Course id */
 233     public $course_id;
 234
 235     /* @var array Completion criteria {@link completion_info::get_criteria()}  */
 236     private $criteria;
 237
 238     /**
 239      * Return array of aggregation methods
 240      * @return array
 241      */
 242     public static function get_aggregation_methods() {
 243         return array(
 244             COMPLETION_AGGREGATION_ALL => get_string('all'),
 245             COMPLETION_AGGREGATION_ANY => get_string('any', 'completion'),
 246         );
 247     }
 248
 249     /**
 250      * Constructs with course details.
 251      *
 252      * When instantiating a new completion info object you must provide a course
 253      * object with at least id, and enablecompletion properties.
 254      *
 255      * @param stdClass $course Moodle course object.
 256      */
 257     public function __construct($course) {
 258         $this->course = $course;
 259         $this->course_id = $course->id;
 260     }
 261
 262     /**
 263      * Determines whether completion is enabled across entire site.
 264      *
 265      * @return bool COMPLETION_ENABLED (true) if completion is enabled for the site,
 266      *     COMPLETION_DISABLED (false) if it's complete
 267      */
 268     public static function is_enabled_for_site() {
 269         global $CFG;
 270         return !empty($CFG->enablecompletion);
 271     }
 272
 273     /**
 274      * Checks whether completion is enabled in a particular course and possibly
 275      * activity.
 276      *
 277      * @param stdClass|cm_info $cm Course-module object. If not specified, returns the course
 278      *   completion enable state.
 279      * @return mixed COMPLETION_ENABLED or COMPLETION_DISABLED (==0) in the case of
 280      *   site and course; COMPLETION_TRACKING_MANUAL, _AUTOMATIC or _NONE (==0)
 281      *   for a course-module.
 282      */
 283     public function is_enabled($cm = null) {
 284         global $CFG, $DB;
 285
 286         // First check global completion
 287         if (!isset($CFG->enablecompletion) || $CFG->enablecompletion == COMPLETION_DISABLED) {
 288             return COMPLETION_DISABLED;
 289         }
 290
 291         // Load data if we do not have enough
 292         if (!isset($this->course->enablecompletion)) {
 293             $this->course->enablecompletion = $DB->get_field('course', 'enablecompletion', array('id' => $this->course->id));
 294         }
 295
 296         // Check course completion
 297         if ($this->course->enablecompletion == COMPLETION_DISABLED) {
 298             return COMPLETION_DISABLED;
 299         }
 300
 301         // If there was no $cm and we got this far, then it's enabled
 302         if (!$cm) {
 303             return COMPLETION_ENABLED;
 304         }
 305
 306         // Return course-module completion value
 307         return $cm->completion;
 308     }
 309
 310     /**
 311      * Displays the 'Your progress' help icon, if completion tracking is enabled.
 312      * Just prints the result of display_help_icon().
 313      *
 314      * @deprecated since Moodle 2.0 - Use display_help_icon instead.
 315      */
 316     public function print_help_icon() {
 317         print $this->display_help_icon();
 318     }
 319
 320     /**
 321      * Returns the 'Your progress' help icon, if completion tracking is enabled.
 322      *
 323      * @return string HTML code for help icon, or blank if not needed
 324      */
 325     public function display_help_icon() {
 326         global $PAGE, $OUTPUT;
 327         $result = '';
 328         if ($this->is_enabled() && !$PAGE->user_is_editing() && isloggedin() && !isguestuser()) {
 329             $result .= html_writer::tag('div', get_string('yourprogress','completion') .
 330                     $OUTPUT->help_icon('completionicons', 'completion'), array('id' => 'completionprogressid',
 331                     'class' => 'completionprogress'));
 332         }
 333         return $result;
 334     }
 335
 336     /**
 337      * Get a course completion for a user
 338      *
 339      * @param int $user_id User id
 340      * @param int $criteriatype Specific criteria type to return
 341      * @return bool|completion_criteria_completion returns false on fail
 342      */
 343     public function get_completion($user_id, $criteriatype) {
 344         $completions = $this->get_completions($user_id, $criteriatype);
 345
 346         if (empty($completions)) {
 347             return false;
 348         } elseif (count($completions) > 1) {
 349             print_error('multipleselfcompletioncriteria', 'completion');
 350         }
 351
 352         return $completions[0];
 353     }
 354
 355     /**
 356      * Get all course criteria's completion objects for a user
 357      *
 358      * @param int $user_id User id
 359      * @param int $criteriatype Specific criteria type to return (optional)
 360      * @return array
 361      */
 362     public function get_completions($user_id, $criteriatype = null) {
 363         $criterion = $this->get_criteria($criteriatype);
 364
 365         $completions = array();
 366
 367         foreach ($criterion as $criteria) {
 368             $params = array(
 369                 'course'        => $this->course_id,
 370                 'userid'        => $user_id,
 371                 'criteriaid'    => $criteria->id
 372             );
 373
 374             $completion = new completion_criteria_completion($params);
 375             $completion->attach_criteria($criteria);
 376
 377             $completions[] = $completion;
 378         }
 379
 380         return $completions;
 381     }
 382
 383     /**
 384      * Get completion object for a user and a criteria
 385      *
 386      * @param int $user_id User id
 387      * @param completion_criteria $criteria Criteria object
 388      * @return completion_criteria_completion
 389      */
 390     public function get_user_completion($user_id, $criteria) {
 391         $params = array(
 392             'course'        => $this->course_id,
 393             'userid'        => $user_id,
 394             'criteriaid'    => $criteria->id,
 395         );
 396
 397         $completion = new completion_criteria_completion($params);
 398         return $completion;
 399     }
 400
 401     /**
 402      * Check if course has completion criteria set
 403      *
 404      * @return bool Returns true if there are criteria
 405      */
 406     public function has_criteria() {
 407         $criteria = $this->get_criteria();
 408
 409         return (bool) count($criteria);
 410     }
 411
 412     /**
 413      * Get course completion criteria
 414      *
 415      * @param int $criteriatype Specific criteria type to return (optional)
 416      */
 417     public function get_criteria($criteriatype = null) {
 418
 419         // Fill cache if empty
 420         if (!is_array($this->criteria)) {
 421             global $DB;
 422
 423             $params = array(
 424                 'course'    => $this->course->id
 425             );
 426
 427             // Load criteria from database
 428             $records = (array)$DB->get_records('course_completion_criteria', $params);
 429
 430             // Build array of criteria objects
 431             $this->criteria = array();
 432             foreach ($records as $record) {
 433                 $this->criteria[$record->id] = completion_criteria::factory((array)$record);
 434             }
 435         }
 436
 437         // If after all criteria
 438         if ($criteriatype === null) {
 439             return $this->criteria;
 440         }
 441
 442         // If we are only after a specific criteria type
 443         $criteria = array();
 444         foreach ($this->criteria as $criterion) {
 445
 446             if ($criterion->criteriatype != $criteriatype) {
 447                 continue;
 448             }
 449
 450             $criteria[$criterion->id] = $criterion;
 451         }
 452
 453         return $criteria;
 454     }
 455
 456     /**
 457      * Get aggregation method
 458      *
 459      * @param int $criteriatype If none supplied, get overall aggregation method (optional)
 460      * @return int One of COMPLETION_AGGREGATION_ALL or COMPLETION_AGGREGATION_ANY
 461      */
 462     public function get_aggregation_method($criteriatype = null) {
 463         $params = array(
 464             'course'        => $this->course_id,
 465             'criteriatype'  => $criteriatype
 466         );
 467
 468         $aggregation = new completion_aggregation($params);
 469
 470         if (!$aggregation->id) {
 471             $aggregation->method = COMPLETION_AGGREGATION_ALL;
 472         }
 473
 474         return $aggregation->method;
 475     }
 476
 477     /**
 478      * Get incomplete course completion criteria
 479      *
 480      * @return array
 481      */
 482     public function get_incomplete_criteria() {
 483         $incomplete = array();
 484
 485         foreach ($this->get_criteria() as $criteria) {
 486             if (!$criteria->is_complete()) {
 487                 $incomplete[] = $criteria;
 488             }
 489         }
 490
 491         return $incomplete;
 492     }
 493
 494     /**
 495      * Clear old course completion criteria
 496      */
 497     public function clear_criteria() {
 498         global $DB;
 499         $DB->delete_records('course_completion_criteria', array('course' => $this->course_id));
 500         $DB->delete_records('course_completion_aggr_methd', array('course' => $this->course_id));
 501
 502         $this->delete_course_completion_data();
 503     }
 504
 505     /**
 506      * Has the supplied user completed this course
 507      *
 508      * @param int $user_id User's id
 509      * @return boolean
 510      */
 511     public function is_course_complete($user_id) {
 512         $params = array(
 513             'userid'    => $user_id,
 514             'course'  => $this->course_id
 515         );
 516
 517         $ccompletion = new completion_completion($params);
 518         return $ccompletion->is_complete();
 519     }
 520
 521     /**
 522      * Updates (if necessary) the completion state of activity $cm for the given
 523      * user.
 524      *
 525      * For manual completion, this function is called when completion is toggled
 526      * with $possibleresult set to the target state.
 527      *
 528      * For automatic completion, this function should be called every time a module
 529      * does something which might influence a user's completion state. For example,
 530      * if a forum provides options for marking itself 'completed' once a user makes
 531      * N posts, this function should be called every time a user makes a new post.
 532      * [After the post has been saved to the database]. When calling, you do not
 533      * need to pass in the new completion state. Instead this function carries out
 534      * completion calculation by checking grades and viewed state itself, and
 535      * calling the involved module via modulename_get_completion_state() to check
 536      * module-specific conditions.
 537      *
 538      * @param stdClass|cm_info $cm Course-module
 539      * @param int $possibleresult Expected completion result. If the event that
 540      *   has just occurred (e.g. add post) can only result in making the activity
 541      *   complete when it wasn't before, use COMPLETION_COMPLETE. If the event that
 542      *   has just occurred (e.g. delete post) can only result in making the activity
 543      *   not complete when it was previously complete, use COMPLETION_INCOMPLETE.
 544      *   Otherwise use COMPLETION_UNKNOWN. Setting this value to something other than
 545      *   COMPLETION_UNKNOWN significantly improves performance because it will abandon
 546      *   processing early if the user's completion state already matches the expected
 547      *   result. For manual events, COMPLETION_COMPLETE or COMPLETION_INCOMPLETE
 548      *   must be used; these directly set the specified state.
 549      * @param int $userid User ID to be updated. Default 0 = current user
 550      * @return void
 551      */
 552     public function update_state($cm, $possibleresult=COMPLETION_UNKNOWN, $userid=0) {
 553         global $USER, $SESSION;
 554
 555         // Do nothing if completion is not enabled for that activity
 556         if (!$this->is_enabled($cm)) {
 557             return;
 558         }
 559
 560         // Get current value of completion state and do nothing if it's same as
 561         // the possible result of this change. If the change is to COMPLETE and the
 562         // current value is one of the COMPLETE_xx subtypes, ignore that as well
 563         $current = $this->get_data($cm, false, $userid);
 564         if ($possibleresult == $current->completionstate ||
 565             ($possibleresult == COMPLETION_COMPLETE &&
 566                 ($current->completionstate == COMPLETION_COMPLETE_PASS ||
 567                 $current->completionstate == COMPLETION_COMPLETE_FAIL))) {
 568             return;
 569         }
 570
 571         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 572             // For manual tracking we set the result directly
 573             switch($possibleresult) {
 574                 case COMPLETION_COMPLETE:
 575                 case COMPLETION_INCOMPLETE:
 576                     $newstate = $possibleresult;
 577                     break;
 578                 default:
 579                     $this->internal_systemerror("Unexpected manual completion state for {$cm->id}: $possibleresult");
 580             }
 581
 582         } else {
 583             // Automatic tracking; get new state
 584             $newstate = $this->internal_get_state($cm, $userid, $current);
 585         }
 586
 587         // If changed, update
 588         if ($newstate != $current->completionstate) {
 589             $current->completionstate = $newstate;
 590             $current->timemodified    = time();
 591             $this->internal_set_data($cm, $current);
 592         }
 593     }
 594
 595     /**
 596      * Calculates the completion state for an activity and user.
 597      *
 598      * Internal function. Not private, so we can unit-test it.
 599      *
 600      * @param stdClass|cm_info $cm Activity
 601      * @param int $userid ID of user
 602      * @param stdClass $current Previous completion information from database
 603      * @return mixed
 604      */
 605     public function internal_get_state($cm, $userid, $current) {
 606         global $USER, $DB, $CFG;
 607
 608         // Get user ID
 609         if (!$userid) {
 610             $userid = $USER->id;
 611         }
 612
 613         // Check viewed
 614         if ($cm->completionview == COMPLETION_VIEW_REQUIRED &&
 615             $current->viewed == COMPLETION_NOT_VIEWED) {
 616
 617             return COMPLETION_INCOMPLETE;
 618         }
 619
 620         // Modname hopefully is provided in $cm but just in case it isn't, let's grab it
 621         if (!isset($cm->modname)) {
 622             $cm->modname = $DB->get_field('modules', 'name', array('id'=>$cm->module));
 623         }
 624
 625         $newstate = COMPLETION_COMPLETE;
 626
 627         // Check grade
 628         if (!is_null($cm->completiongradeitemnumber)) {
 629             require_once($CFG->libdir.'/gradelib.php');
 630             $item = grade_item::fetch(array('courseid'=>$cm->course, 'itemtype'=>'mod',
 631                 'itemmodule'=>$cm->modname, 'iteminstance'=>$cm->instance,
 632                 'itemnumber'=>$cm->completiongradeitemnumber));
 633             if ($item) {
 634                 // Fetch 'grades' (will be one or none)
 635                 $grades = grade_grade::fetch_users_grades($item, array($userid), false);
 636                 if (empty($grades)) {
 637                     // No grade for user
 638                     return COMPLETION_INCOMPLETE;
 639                 }
 640                 if (count($grades) > 1) {
 641                     $this->internal_systemerror("Unexpected result: multiple grades for
 642                         item '{$item->id}', user '{$userid}'");
 643                 }
 644                 $newstate = self::internal_get_grade_state($item, reset($grades));
 645                 if ($newstate == COMPLETION_INCOMPLETE) {
 646                     return COMPLETION_INCOMPLETE;
 647                 }
 648
 649             } else {
 650                 $this->internal_systemerror("Cannot find grade item for '{$cm->modname}'
 651                     cm '{$cm->id}' matching number '{$cm->completiongradeitemnumber}'");
 652             }
 653         }
 654
 655         if (plugin_supports('mod', $cm->modname, FEATURE_COMPLETION_HAS_RULES)) {
 656             $function = $cm->modname.'_get_completion_state';
 657             if (!function_exists($function)) {
 658                 $this->internal_systemerror("Module {$cm->modname} claims to support
 659                     FEATURE_COMPLETION_HAS_RULES but does not have required
 660                     {$cm->modname}_get_completion_state function");
 661             }
 662             if (!$function($this->course, $cm, $userid, COMPLETION_AND)) {
 663                 return COMPLETION_INCOMPLETE;
 664             }
 665         }
 666
 667         return $newstate;
 668
 669     }
 670
 671     /**
 672      * Marks a module as viewed.
 673      *
 674      * Should be called whenever a module is 'viewed' (it is up to the module how to
 675      * determine that). Has no effect if viewing is not set as a completion condition.
 676      *
 677      * Note that this function must be called before you print the page header because
 678      * it is possible that the navigation block may depend on it. If you call it after
 679      * printing the header, it shows a developer debug warning.
 680      *
 681      * @param stdClass|cm_info $cm Activity
 682      * @param int $userid User ID or 0 (default) for current user
 683      * @return void
 684      */
 685     public function set_module_viewed($cm, $userid=0) {
 686         global $PAGE;
 687         if ($PAGE->headerprinted) {
 688             debugging('set_module_viewed must be called before header is printed',
 689                     DEBUG_DEVELOPER);
 690         }
 691
 692         // Don't do anything if view condition is not turned on
 693         if ($cm->completionview == COMPLETION_VIEW_NOT_REQUIRED || !$this->is_enabled($cm)) {
 694             return;
 695         }
 696
 697         // Get current completion state
 698         $data = $this->get_data($cm, false, $userid);
 699
 700         // If we already viewed it, don't do anything
 701         if ($data->viewed == COMPLETION_VIEWED) {
 702             return;
 703         }
 704
 705         // OK, change state, save it, and update completion
 706         $data->viewed = COMPLETION_VIEWED;
 707         $this->internal_set_data($cm, $data);
 708         $this->update_state($cm, COMPLETION_COMPLETE, $userid);
 709     }
 710
 711     /**
 712      * Determines how much completion data exists for an activity. This is used when
 713      * deciding whether completion information should be 'locked' in the module
 714      * editing form.
 715      *
 716      * @param cm_info $cm Activity
 717      * @return int The number of users who have completion data stored for this
 718      *   activity, 0 if none
 719      */
 720     public function count_user_data($cm) {
 721         global $DB;
 722
 723         return $DB->get_field_sql("
 724     SELECT
 725         COUNT(1)
 726     FROM
 727         {course_modules_completion}
 728     WHERE
 729         coursemoduleid=? AND completionstate<>0", array($cm->id));
 730     }
 731
 732     /**
 733      * Determines how much course completion data exists for a course. This is used when
 734      * deciding whether completion information should be 'locked' in the completion
 735      * settings form and activity completion settings.
 736      *
 737      * @param int $user_id Optionally only get course completion data for a single user
 738      * @return int The number of users who have completion data stored for this
 739      *     course, 0 if none
 740      */
 741     public function count_course_user_data($user_id = null) {
 742         global $DB;
 743
 744         $sql = '
 745     SELECT
 746         COUNT(1)
 747     FROM
 748         {course_completion_crit_compl}
 749     WHERE
 750         course = ?
 751         ';
 752
 753         $params = array($this->course_id);
 754
 755         // Limit data to a single user if an ID is supplied
 756         if ($user_id) {
 757             $sql .= ' AND userid = ?';
 758             $params[] = $user_id;
 759         }
 760
 761         return $DB->get_field_sql($sql, $params);
 762     }
 763
 764     /**
 765      * Check if this course's completion criteria should be locked
 766      *
 767      * @return boolean
 768      */
 769     public function is_course_locked() {
 770         return (bool) $this->count_course_user_data();
 771     }
 772
 773     /**
 774      * Deletes all course completion completion data.
 775      *
 776      * Intended to be used when unlocking completion criteria settings.
 777      */
 778     public function delete_course_completion_data() {
 779         global $DB;
 780
 781         $DB->delete_records('course_completions', array('course' => $this->course_id));
 782         $DB->delete_records('course_completion_crit_compl', array('course' => $this->course_id));
 783     }
 784
 785     /**
 786      * Deletes all activity and course completion data for an entire course
 787      * (the below delete_all_state function does this for a single activity).
 788      *
 789      * Used by course reset page.
 790      */
 791     public function delete_all_completion_data() {
 792         global $DB, $SESSION;
 793
 794         // Delete from database.
 795         $DB->delete_records_select('course_modules_completion',
 796                 'coursemoduleid IN (SELECT id FROM {course_modules} WHERE course=?)',
 797                 array($this->course_id));
 798
 799         // Reset cache for current user.
 800         if (isset($SESSION->completioncache) &&
 801             array_key_exists($this->course_id, $SESSION->completioncache)) {
 802
 803             unset($SESSION->completioncache[$this->course_id]);
 804         }
 805
 806         // Wipe course completion data too.
 807         $this->delete_course_completion_data();
 808     }
 809
 810     /**
 811      * Deletes completion state related to an activity for all users.
 812      *
 813      * Intended for use only when the activity itself is deleted.
 814      *
 815      * @param stdClass|cm_info $cm Activity
 816      */
 817     public function delete_all_state($cm) {
 818         global $SESSION, $DB;
 819
 820         // Delete from database
 821         $DB->delete_records('course_modules_completion', array('coursemoduleid'=>$cm->id));
 822
 823         // Erase cache data for current user if applicable
 824         if (isset($SESSION->completioncache) &&
 825             array_key_exists($cm->course, $SESSION->completioncache) &&
 826             array_key_exists($cm->id, $SESSION->completioncache[$cm->course])) {
 827
 828             unset($SESSION->completioncache[$cm->course][$cm->id]);
 829         }
 830
 831         // Check if there is an associated course completion criteria
 832         $criteria = $this->get_criteria(COMPLETION_CRITERIA_TYPE_ACTIVITY);
 833         $acriteria = false;
 834         foreach ($criteria as $criterion) {
 835             if ($criterion->moduleinstance == $cm->id) {
 836                 $acriteria = $criterion;
 837                 break;
 838             }
 839         }
 840
 841         if ($acriteria) {
 842             // Delete all criteria completions relating to this activity
 843             $DB->delete_records('course_completion_crit_compl', array('course' => $this->course_id, 'criteriaid' => $acriteria->id));
 844             $DB->delete_records('course_completions', array('course' => $this->course_id));
 845         }
 846     }
 847
 848     /**
 849      * Recalculates completion state related to an activity for all users.
 850      *
 851      * Intended for use if completion conditions change. (This should be avoided
 852      * as it may cause some things to become incomplete when they were previously
 853      * complete, with the effect - for example - of hiding a later activity that
 854      * was previously available.)
 855      *
 856      * Resetting state of manual tickbox has same result as deleting state for
 857      * it.
 858      *
 859      * @param stcClass|cm_info $cm Activity
 860      */
 861     public function reset_all_state($cm) {
 862         global $DB;
 863
 864         if ($cm->completion == COMPLETION_TRACKING_MANUAL) {
 865             $this->delete_all_state($cm);
 866             return;
 867         }
 868         // Get current list of users with completion state
 869         $rs = $DB->get_recordset('course_modules_completion', array('coursemoduleid'=>$cm->id), '', 'userid');
 870         $keepusers = array();
 871         foreach ($rs as $rec) {
 872             $keepusers[] = $rec->userid;
 873         }
 874         $rs->close();
 875
 876         // Delete all existing state [also clears session cache for current user]
 877         $this->delete_all_state($cm);
 878
 879         // Merge this with list of planned users (according to roles)
 880         $trackedusers = $this->get_tracked_users();
 881         foreach ($trackedusers as $trackeduser) {
 882             $keepusers[] = $trackeduser->id;
 883         }
 884         $keepusers = array_unique($keepusers);
 885
 886         // Recalculate state for each kept user
 887         foreach ($keepusers as $keepuser) {
 888             $this->update_state($cm, COMPLETION_UNKNOWN, $keepuser);
 889         }
 890     }
 891
 892     /**
 893      * Obtains completion data for a particular activity and user (from the
 894      * session cache if available, or by SQL query)
 895      *
 896      * @param stcClass|cm_info $cm Activity; only required field is ->id
 897      * @param bool $wholecourse If true (default false) then, when necessary to
 898      *   fill the cache, retrieves information from the entire course not just for
 899      *   this one activity
 900      * @param int $userid User ID or 0 (default) for current user
 901      * @param array $modinfo Supply the value here - this is used for unit
 902      *   testing and so that it can be called recursively from within
 903      *   get_fast_modinfo. (Needs only list of all CMs with IDs.)
 904      *   Otherwise the method calls get_fast_modinfo itself.
 905      * @return object Completion data (record from course_modules_completion)
 906      */
 907     public function get_data($cm, $wholecourse = false, $userid = 0, $modinfo = null) {
 908         global $USER, $CFG, $SESSION, $DB;
 909
 910         // Get user ID
 911         if (!$userid) {
 912             $userid = $USER->id;
 913         }
 914
 915         // Is this the current user?
 916         $currentuser = $userid==$USER->id;
 917
 918         if ($currentuser && is_object($SESSION)) {
 919             // Make sure cache is present and is for current user (loginas
 920             // changes this)
 921             if (!isset($SESSION->completioncache) || $SESSION->completioncacheuserid!=$USER->id) {
 922                 $SESSION->completioncache = array();
 923                 $SESSION->completioncacheuserid = $USER->id;
 924             }
 925             // Expire any old data from cache
 926             foreach ($SESSION->completioncache as $courseid=>$activities) {
 927                 if (empty($activities['updated']) || $activities['updated'] < time()-COMPLETION_CACHE_EXPIRY) {
 928                     unset($SESSION->completioncache[$courseid]);
 929                 }
 930             }
 931             // See if requested data is present, if so use cache to get it
 932             if (isset($SESSION->completioncache) &&
 933                 array_key_exists($this->course->id, $SESSION->completioncache) &&
 934                 array_key_exists($cm->id, $SESSION->completioncache[$this->course->id])) {
 935                 return $SESSION->completioncache[$this->course->id][$cm->id];
 936             }
 937         }
 938
 939         // Not there, get via SQL
 940         if ($currentuser && $wholecourse) {
 941             // Get whole course data for cache
 942             $alldatabycmc = $DB->get_records_sql("
 943     SELECT
 944         cmc.*
 945     FROM
 946         {course_modules} cm
 947         INNER JOIN {course_modules_completion} cmc ON cmc.coursemoduleid=cm.id
 948     WHERE
 949         cm.course=? AND cmc.userid=?", array($this->course->id, $userid));
 950
 951             // Reindex by cm id
 952             $alldata = array();
 953             if ($alldatabycmc) {
 954                 foreach ($alldatabycmc as $data) {
 955                     $alldata[$data->coursemoduleid] = $data;
 956                 }
 957             }
 958
 959             // Get the module info and build up condition info for each one
 960             if (empty($modinfo)) {
 961                 $modinfo = get_fast_modinfo($this->course, $userid);
 962             }
 963             foreach ($modinfo->cms as $othercm) {
 964                 if (array_key_exists($othercm->id, $alldata)) {
 965                     $data = $alldata[$othercm->id];
 966                 } else {
 967                     // Row not present counts as 'not complete'
 968                     $data = new StdClass;
 969                     $data->id              = 0;
 970                     $data->coursemoduleid  = $othercm->id;
 971                     $data->userid          = $userid;
 972                     $data->completionstate = 0;
 973                     $data->viewed          = 0;
 974                     $data->timemodified    = 0;
 975                 }
 976                 $SESSION->completioncache[$this->course->id][$othercm->id] = $data;
 977             }
 978             $SESSION->completioncache[$this->course->id]['updated'] = time();
 979
 980             if (!isset($SESSION->completioncache[$this->course->id][$cm->id])) {
 981                 $this->internal_systemerror("Unexpected error: course-module {$cm->id} could not be found on course {$this->course->id}");
 982             }
 983             return $SESSION->completioncache[$this->course->id][$cm->id];
 984
 985         } else {
 986             // Get single record
 987             $data = $DB->get_record('course_modules_completion', array('coursemoduleid'=>$cm->id, 'userid'=>$userid));
 988             if ($data == false) {
 989                 // Row not present counts as 'not complete'
 990                 $data = new StdClass;
 991                 $data->id              = 0;
 992                 $data->coursemoduleid  = $cm->id;
 993                 $data->userid          = $userid;
 994                 $data->completionstate = 0;
 995                 $data->viewed          = 0;
 996                 $data->timemodified    = 0;
 997             }
 998
 999             // Put in cache
1000             if ($currentuser) {
1001                 $SESSION->completioncache[$this->course->id][$cm->id] = $data;
1002                 // For single updates, only set date if it was empty before
1003                 if (empty($SESSION->completioncache[$this->course->id]['updated'])) {
1004                     $SESSION->completioncache[$this->course->id]['updated'] = time();
1005                 }
1006             }
1007         }
1008
1009         return $data;
1010     }
1011
1012     /**
1013      * Updates completion data for a particular coursemodule and user (user is
1014      * determined from $data).
1015      *
1016      * (Internal function. Not private, so we can unit-test it.)
1017      *
1018      * @param stdClass|cm_info $cm Activity
1019      * @param stdClass $data Data about completion for that user
1020      */
1021     public function internal_set_data($cm, $data) {
1022         global $USER, $SESSION, $DB;
1023
1024         $transaction = $DB->start_delegated_transaction();
1025         if (!$data->id) {
1026             // Check there isn't really a row
1027             $data->id = $DB->get_field('course_modules_completion', 'id',
1028                     array('coursemoduleid'=>$data->coursemoduleid, 'userid'=>$data->userid));
1029         }
1030         if (!$data->id) {
1031             // Didn't exist before, needs creating
1032             $data->id = $DB->insert_record('course_modules_completion', $data);
1033         } else {
1034             // Has real (nonzero) id meaning that a database row exists, update
1035             $DB->update_record('course_modules_completion', $data);
1036         }
1037         $transaction->allow_commit();
1038
1039         events_trigger('activity_completion_changed', $data);
1040
1041         if ($data->userid == $USER->id) {
1042             $SESSION->completioncache[$cm->course][$cm->id] = $data;
1043             // reset modinfo for user (no need to call rebuild_course_cache())
1044             get_fast_modinfo($cm->course, 0, true);
1045         }
1046     }
1047
1048      /**
1049      * Return whether or not the course has activities with completion enabled.
1050      *
1051      * @return boolean true when there is at least one activity with completion enabled.
1052      */
1053     public function has_activities() {
1054         $modinfo = get_fast_modinfo($this->course);
1055         foreach ($modinfo->get_cms() as $cm) {
1056             if ($cm->completion != COMPLETION_TRACKING_NONE) {
1057                 return true;
1058             }
1059         }
1060         return false;
1061     }
1062
1063     /**
1064      * Obtains a list of activities for which completion is enabled on the
1065      * course. The list is ordered by the section order of those activities.
1066      *
1067      * @return array Array from $cmid => $cm of all activities with completion enabled,
1068      *   empty array if none
1069      */
1070     public function get_activities() {
1071         $modinfo = get_fast_modinfo($this->course);
1072         $result = array();
1073         foreach ($modinfo->get_cms() as $cm) {
1074             if ($cm->completion != COMPLETION_TRACKING_NONE) {
1075                 $result[$cm->id] = $cm;
1076             }
1077         }
1078         return $result;
1079     }
1080
1081     /**
1082      * Checks to see if the userid supplied has a tracked role in
1083      * this course
1084      *
1085      * @param int $userid User id
1086      * @return bool
1087      */
1088     public function is_tracked_user($userid) {
1089         return is_enrolled(context_course::instance($this->course->id), $userid, 'moodle/course:isincompletionreports', true);
1090     }
1091
1092     /**
1093      * Returns the number of users whose progress is tracked in this course.
1094      *
1095      * Optionally supply a search's where clause, or a group id.
1096      *
1097      * @param string $where Where clause sql (use 'u.whatever' for user table fields)
1098      * @param array $whereparams Where clause params
1099      * @param int $groupid Group id
1100      * @return int Number of tracked users
1101      */
1102     public function get_num_tracked_users($where = '', $whereparams = array(), $groupid = 0) {
1103         global $DB;
1104
1105         list($enrolledsql, $enrolledparams) = get_enrolled_sql(
1106                 context_course::instance($this->course->id), 'moodle/course:isincompletionreports', $groupid, true);
1107         $sql  = 'SELECT COUNT(eu.id) FROM (' . $enrolledsql . ') eu JOIN {user} u ON u.id = eu.id';
1108         if ($where) {
1109             $sql .= " WHERE $where";
1110         }
1111
1112         $params = array_merge($enrolledparams, $whereparams);
1113         return $DB->count_records_sql($sql, $params);
1114     }
1115
1116     /**
1117      * Return array of users whose progress is tracked in this course.
1118      *
1119      * Optionally supply a search's where clause, group id, sorting, paging.
1120      *
1121      * @param string $where Where clause sql, referring to 'u.' fields (optional)
1122      * @param array $whereparams Where clause params (optional)
1123      * @param int $groupid Group ID to restrict to (optional)
1124      * @param string $sort Order by clause (optional)
1125      * @param int $limitfrom Result start (optional)
1126      * @param int $limitnum Result max size (optional)
1127      * @param context $extracontext If set, includes extra user information fields
1128      *   as appropriate to display for current user in this context
1129      * @return array Array of user objects with standard user fields
1130      */
1131     public function get_tracked_users($where = '', $whereparams = array(), $groupid = 0,
1132              $sort = '', $limitfrom = '', $limitnum = '', context $extracontext = null) {
1133
1134         global $DB;
1135
1136         list($enrolledsql, $params) = get_enrolled_sql(
1137                 context_course::instance($this->course->id),
1138                 'moodle/course:isincompletionreports', $groupid, true);
1139
1140         $sql = 'SELECT u.id, u.firstname, u.lastname, u.idnumber';
1141         if ($extracontext) {
1142             $sql .= get_extra_user_fields_sql($extracontext, 'u', '', array('idnumber'));
1143         }
1144         $sql .= ' FROM (' . $enrolledsql . ') eu JOIN {user} u ON u.id = eu.id';
1145
1146         if ($where) {
1147             $sql .= " AND $where";
1148             $params = array_merge($params, $whereparams);
1149         }
1150
1151         if ($sort) {
1152             $sql .= " ORDER BY $sort";
1153         }
1154
1155         return $DB->get_records_sql($sql, $params, $limitfrom, $limitnum);
1156     }
1157
1158     /**
1159      * Obtains progress information across a course for all users on that course, or
1160      * for all users in a specific group. Intended for use when displaying progress.
1161      *
1162      * This includes only users who, in course context, have one of the roles for
1163      * which progress is tracked (the gradebookroles admin option) and are enrolled in course.
1164      *
1165      * Users are included (in the first array) even if they do not have
1166      * completion progress for any course-module.
1167      *
1168      * @param bool $sortfirstname If true, sort by first name, otherwise sort by
1169      *   last name
1170      * @param string $where Where clause sql (optional)
1171      * @param array $where_params Where clause params (optional)
1172      * @param int $groupid Group ID or 0 (default)/false for all groups
1173      * @param int $pagesize Number of users to actually return (optional)
1174      * @param int $start User to start at if paging (optional)
1175      * @param context $extracontext If set, includes extra user information fields
1176      *   as appropriate to display for current user in this context
1177      * @return stdClass with ->total and ->start (same as $start) and ->users;
1178      *   an array of user objects (like mdl_user id, firstname, lastname)
1179      *   containing an additional ->progress array of coursemoduleid => completionstate
1180      */
1181     public function get_progress_all($where = '', $where_params = array(), $groupid = 0,
1182             $sort = '', $pagesize = '', $start = '', context $extracontext = null) {
1183         global $CFG, $DB;
1184
1185         // Get list of applicable users
1186         $users = $this->get_tracked_users($where, $where_params, $groupid, $sort,
1187                 $start, $pagesize, $extracontext);
1188
1189         // Get progress information for these users in groups of 1, 000 (if needed)
1190         // to avoid making the SQL IN too long
1191         $results = array();
1192         $userids = array();
1193         foreach ($users as $user) {
1194             $userids[] = $user->id;
1195             $results[$user->id] = $user;
1196             $results[$user->id]->progress = array();
1197         }
1198
1199         for($i=0; $i<count($userids); $i+=1000) {
1200             $blocksize = count($userids)-$i < 1000 ? count($userids)-$i : 1000;
1201
1202             list($insql, $params) = $DB->get_in_or_equal(array_slice($userids, $i, $blocksize));
1203             array_splice($params, 0, 0, array($this->course->id));
1204             $rs = $DB->get_recordset_sql("
1205                 SELECT
1206                     cmc.*
1207                 FROM
1208                     {course_modules} cm
1209                     INNER JOIN {course_modules_completion} cmc ON cm.id=cmc.coursemoduleid
1210                 WHERE
1211                     cm.course=? AND cmc.userid $insql", $params);
1212             foreach ($rs as $progress) {
1213                 $progress = (object)$progress;
1214                 $results[$progress->userid]->progress[$progress->coursemoduleid] = $progress;
1215             }
1216             $rs->close();
1217         }
1218
1219         return $results;
1220     }
1221
1222     /**
1223      * Called by grade code to inform the completion system when a grade has
1224      * been changed. If the changed grade is used to determine completion for
1225      * the course-module, then the completion status will be updated.
1226      *
1227      * @param stdClass|cm_info $cm Course-module for item that owns grade
1228      * @param grade_item $item Grade item
1229      * @param stdClass $grade
1230      * @param bool $deleted
1231      */
1232     public function inform_grade_changed($cm, $item, $grade, $deleted) {
1233         // Bail out now if completion is not enabled for course-module, it is enabled
1234         // but is set to manual, grade is not used to compute completion, or this
1235         // is a different numbered grade
1236         if (!$this->is_enabled($cm) ||
1237             $cm->completion == COMPLETION_TRACKING_MANUAL ||
1238             is_null($cm->completiongradeitemnumber) ||
1239             $item->itemnumber != $cm->completiongradeitemnumber) {
1240             return;
1241         }
1242
1243         // What is the expected result based on this grade?
1244         if ($deleted) {
1245             // Grade being deleted, so only change could be to make it incomplete
1246             $possibleresult = COMPLETION_INCOMPLETE;
1247         } else {
1248             $possibleresult = self::internal_get_grade_state($item, $grade);
1249         }
1250
1251         // OK, let's update state based on this
1252         $this->update_state($cm, $possibleresult, $grade->userid);
1253     }
1254
1255     /**
1256      * Calculates the completion state that would result from a graded item
1257      * (where grade-based completion is turned on) based on the actual grade
1258      * and settings.
1259      *
1260      * Internal function. Not private, so we can unit-test it.
1261      *
1262      * @param grade_item $item an instance of grade_item
1263      * @param grade_grade $grade an instance of grade_grade
1264      * @return int Completion state e.g. COMPLETION_INCOMPLETE
1265      */
1266     public static function internal_get_grade_state($item, $grade) {
1267         if (!$grade) {
1268             return COMPLETION_INCOMPLETE;
1269         }
1270         // Conditions to show pass/fail:
1271         // a) Grade has pass mark (default is 0.00000 which is boolean true so be careful)
1272         // b) Grade is visible (neither hidden nor hidden-until)
1273         if ($item->gradepass && $item->gradepass > 0.000009 && !$item->hidden) {
1274             // Use final grade if set otherwise raw grade
1275             $score = !is_null($grade->finalgrade) ? $grade->finalgrade : $grade->rawgrade;
1276
1277             // We are displaying and tracking pass/fail
1278             if ($score >= $item->gradepass) {
1279                 return COMPLETION_COMPLETE_PASS;
1280             } else {
1281                 return COMPLETION_COMPLETE_FAIL;
1282             }
1283         } else {
1284             // Not displaying pass/fail, so just if there is a grade
1285             if (!is_null($grade->finalgrade) || !is_null($grade->rawgrade)) {
1286                 // Grade exists, so maybe complete now
1287                 return COMPLETION_COMPLETE;
1288             } else {
1289                 // Grade does not exist, so maybe incomplete now
1290                 return COMPLETION_INCOMPLETE;
1291             }
1292         }
1293     }
1294
1295     /**
1296      * Aggregate activity completion state
1297      *
1298      * @param   int     $type   Aggregation type (COMPLETION_* constant)
1299      * @param   bool    $old    Old state
1300      * @param   bool    $new    New state
1301      * @return  bool
1302      */
1303     public static function aggregate_completion_states($type, $old, $new) {
1304         if ($type == COMPLETION_AND) {
1305             return $old && $new;
1306         } else {
1307             return $old || $new;
1308         }
1309     }
1310
1311     /**
1312      * This is to be used only for system errors (things that shouldn't happen)
1313      * and not user-level errors.
1314      *
1315      * @global type $CFG
1316      * @param string $error Error string (will not be displayed to user unless debugging is enabled)
1317      * @throws moodle_exception Exception with the error string as debug info
1318      */
1319     public function internal_systemerror($error) {
1320         global $CFG;
1321         throw new moodle_exception('err_system','completion',
1322             $CFG->wwwroot.'/course/view.php?id='.$this->course->id,null,$error);
1323     }
1324
1325     /**
1326      * For testing only. Wipes information cached in user session.
1327      */
1328     public static function wipe_session_cache() {
1329         global $SESSION;
1330         unset($SESSION->completioncache);
1331         unset($SESSION->completioncacheuserid);
1332     }
1333 }