lib/grade/grade_outcome.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  * Definition of grade outcome class
  19  *
  20  * @package   core_grades
  21  * @category  grade
  22  * @copyright 2006 Nicolas Connault
  23  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26 defined('MOODLE_INTERNAL') || die();
  27
  28 require_once('grade_object.php');
  29
  30 /**
  31  * Class representing a grade outcome.
  32  *
  33  * It is responsible for handling its DB representation, modifying and returning its metadata.
  34  *
  35  * @package   core_grades
  36  * @category  grade
  37  * @copyright 2006 Nicolas Connault
  38  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  39  */
  40 class grade_outcome extends grade_object {
  41     /**
  42      * DB Table (used by grade_object).
  43      * @var string $table
  44      */
  45     public $table = 'grade_outcomes';
  46
  47     /**
  48      * Array of required table fields, must start with 'id'.
  49      * @var array $required_fields
  50      */
  51     public $required_fields = array('id', 'courseid', 'shortname', 'fullname', 'scaleid','description',
  52                                  'descriptionformat', 'timecreated', 'timemodified', 'usermodified');
  53
  54     /**
  55      * The course this outcome belongs to.
  56      * @var int $courseid
  57      */
  58     public $courseid;
  59
  60     /**
  61      * The shortname of the outcome.
  62      * @var string $shortname
  63      */
  64     public $shortname;
  65
  66     /**
  67      * The fullname of the outcome.
  68      * @var string $fullname
  69      */
  70     public $fullname;
  71
  72     /**
  73      * A full grade_scale object referenced by $this->scaleid.
  74      * @var object $scale
  75      */
  76     public $scale;
  77
  78     /**
  79      * The id of the scale referenced by this outcome.
  80      * @var int $scaleid
  81      */
  82     public $scaleid;
  83
  84     /**
  85      * The description of this outcome - FORMAT_MOODLE.
  86      * @var string $description
  87      */
  88     public $description;
  89
  90     /**
  91      * The userid of the person who last modified this outcome.
  92      *
  93      * @var int $usermodified
  94      */
  95     public $usermodified;
  96
  97     /**
  98      * Deletes this outcome from the database.
  99      *
 100      * @param string $source from where was the object deleted (mod/forum, manual, etc.)
 101      * @return bool success
 102      */
 103     public function delete($source=null) {
 104         global $DB;
 105         if (!empty($this->courseid)) {
 106             $DB->delete_records('grade_outcomes_courses', array('outcomeid' => $this->id, 'courseid' => $this->courseid));
 107         }
 108         if (parent::delete($source)) {
 109             $context = context_system::instance();
 110             $fs = get_file_storage();
 111             $files = $fs->get_area_files($context->id, 'grade', 'outcome', $this->id);
 112             foreach ($files as $file) {
 113                 $file->delete();
 114             }
 115             return true;
 116         }
 117         return false;
 118     }
 119
 120     /**
 121      * Records this object in the Database, sets its id to the returned value, and returns that value.
 122      * If successful this function also fetches the new object data from database and stores it
 123      * in object properties.
 124      *
 125      * @param string $source from where was the object inserted (mod/forum, manual, etc.)
 126      * @return int PK ID if successful, false otherwise
 127      */
 128     public function insert($source=null) {
 129         global $DB;
 130
 131         $this->timecreated = $this->timemodified = time();
 132
 133         if ($result = parent::insert($source)) {
 134             if (!empty($this->courseid)) {
 135                 $goc = new stdClass();
 136                 $goc->courseid = $this->courseid;
 137                 $goc->outcomeid = $this->id;
 138                 $DB->insert_record('grade_outcomes_courses', $goc);
 139             }
 140         }
 141         return $result;
 142     }
 143
 144     /**
 145      * In addition to update() it also updates grade_outcomes_courses if needed
 146      *
 147      * @param string $source from where was the object inserted
 148      * @return bool success
 149      */
 150     public function update($source=null) {
 151         $this->timemodified = time();
 152
 153         if ($result = parent::update($source)) {
 154             if (!empty($this->courseid)) {
 155                 $this->use_in($this->courseid);
 156             }
 157         }
 158         return $result;
 159     }
 160
 161     /**
 162      * Mark outcome as used in a course
 163      *
 164      * @param int $courseid
 165      * @return False if invalid courseid requested
 166      */
 167     public function use_in($courseid) {
 168         global $DB;
 169         if (!empty($this->courseid) and $courseid != $this->courseid) {
 170             return false;
 171         }
 172
 173         if (!$DB->record_exists('grade_outcomes_courses', array('courseid' => $courseid, 'outcomeid' => $this->id))) {
 174             $goc = new stdClass();
 175             $goc->courseid  = $courseid;
 176             $goc->outcomeid = $this->id;
 177             $DB->insert_record('grade_outcomes_courses', $goc);
 178         }
 179         return true;
 180     }
 181
 182     /**
 183      * Finds and returns a grade_outcome instance based on params.
 184      *
 185      * @static
 186      * @param array $params associative arrays varname=>value
 187      * @return object grade_outcome instance or false if none found.
 188      */
 189     public static function fetch($params) {
 190         return grade_object::fetch_helper('grade_outcomes', 'grade_outcome', $params);
 191     }
 192
 193     /**
 194      * Finds and returns all grade_outcome instances based on params.
 195      *
 196      * @static
 197      * @param array $params associative arrays varname=>value
 198      * @return array array of grade_outcome insatnces or false if none found.
 199      */
 200     public static function fetch_all($params) {
 201         return grade_object::fetch_all_helper('grade_outcomes', 'grade_outcome', $params);
 202     }
 203
 204     /**
 205      * Instantiates a grade_scale object whose data is retrieved from the database
 206      *
 207      * @return grade_scale
 208      */
 209     public function load_scale() {
 210         if (empty($this->scale->id) or $this->scale->id != $this->scaleid) {
 211             $this->scale = grade_scale::fetch(array('id'=>$this->scaleid));
 212             $this->scale->load_items();
 213         }
 214         return $this->scale;
 215     }
 216
 217     /**
 218      * Static function returning all global outcomes
 219      *
 220      * @static
 221      * @return array
 222      */
 223     public static function fetch_all_global() {
 224         if (!$outcomes = grade_outcome::fetch_all(array('courseid'=>null))) {
 225             $outcomes = array();
 226         }
 227         return $outcomes;
 228     }
 229
 230     /**
 231      * Static function returning all local course outcomes
 232      *
 233      * @static
 234      * @param int $courseid
 235      * @return array
 236      */
 237     public static function fetch_all_local($courseid) {
 238         if (!$outcomes =grade_outcome::fetch_all(array('courseid'=>$courseid))) {
 239             $outcomes = array();
 240         }
 241         return $outcomes;
 242     }
 243
 244     /**
 245      * Static method that returns all outcomes available in course
 246      *
 247      * @static
 248      * @param int $courseid
 249      * @return array
 250      */
 251     public static function fetch_all_available($courseid) {
 252         global $CFG, $DB;
 253
 254         $result = array();
 255         $params = array($courseid);
 256         $sql = "SELECT go.*
 257                   FROM {grade_outcomes} go, {grade_outcomes_courses} goc
 258                  WHERE go.id = goc.outcomeid AND goc.courseid = ?
 259               ORDER BY go.id ASC";
 260
 261         if ($datas = $DB->get_records_sql($sql, $params)) {
 262             foreach($datas as $data) {
 263                 $instance = new grade_outcome();
 264                 grade_object::set_properties($instance, $data);
 265                 $result[$instance->id] = $instance;
 266             }
 267         }
 268         return $result;
 269     }
 270
 271
 272     /**
 273      * Returns the most descriptive field for this object. This is a standard method used
 274      * when we do not know the exact type of an object.
 275      *
 276      * @return string name
 277      */
 278     public function get_name() {
 279         return format_string($this->fullname);
 280     }
 281
 282     /**
 283      * Returns unique outcome short name.
 284      *
 285      * @return string name
 286      */
 287     public function get_shortname() {
 288         return $this->shortname;
 289     }
 290
 291     /**
 292      * Returns the formatted grade description with URLs converted
 293      *
 294      * @return string
 295      */
 296     public function get_description() {
 297         global $CFG;
 298         require_once($CFG->libdir . '/filelib.php');
 299
 300         $options = new stdClass;
 301         $options->noclean = true;
 302         $systemcontext = context_system::instance();
 303         $description = file_rewrite_pluginfile_urls($this->description, 'pluginfile.php', $systemcontext->id, 'grade', 'outcome', $this->id);
 304         return format_text($description, $this->descriptionformat, $options);
 305     }
 306
 307     /**
 308      * Checks if outcome can be deleted.
 309      *
 310      * @return bool
 311      */
 312     public function can_delete() {
 313         if ($this->get_item_uses_count()) {
 314             return false;
 315         }
 316         if (empty($this->courseid)) {
 317             if ($this->get_course_uses_count()) {
 318                 return false;
 319             }
 320         }
 321         return true;
 322     }
 323
 324     /**
 325      * Returns the number of places where outcome is used.
 326      *
 327      * @return int
 328      */
 329     public function get_course_uses_count() {
 330         global $DB;
 331
 332         if (!empty($this->courseid)) {
 333             return 1;
 334         }
 335
 336         return $DB->count_records('grade_outcomes_courses', array('outcomeid' => $this->id));
 337     }
 338
 339     /**
 340      * Returns the number of grade items that use this grade outcome
 341      *
 342      * @return int
 343      */
 344     public function get_item_uses_count() {
 345         global $DB;
 346         return $DB->count_records('grade_items', array('outcomeid' => $this->id));
 347     }
 348
 349     /**
 350      * Computes then returns extra information about this outcome and other objects that are linked to it.
 351      * The average of all grades that use this outcome, for all courses (or 1 course if courseid is given) can
 352      * be requested, and is returned as a float if requested alone. If the list of items that use this outcome
 353      * is also requested, then a single array is returned, which contains the grade_items AND the average grade
 354      * if such is still requested (array('items' => array(...), 'avg' => 2.30)). This combining of two
 355      * methods into one is to save on DB queries, since both queries are similar and can be performed together.
 356      *
 357      * @param int $courseid An optional courseid to narrow down the average to 1 course only
 358      * @param bool $average Whether or not to return the average grade for this outcome
 359      * @param bool $items Whether or not to return the list of items using this outcome
 360      * @return float
 361      */
 362     public function get_grade_info($courseid=null, $average=true, $items=false) {
 363         global $CFG, $DB;
 364
 365         if (!isset($this->id)) {
 366             debugging("You must setup the outcome's id before calling its get_grade_info() method!");
 367             return false; // id must be defined for this to work
 368         }
 369
 370         if ($average === false && $items === false) {
 371             debugging('Either the 1st or 2nd param of grade_outcome::get_grade_info() must be true, or both, but not both false!');
 372             return false;
 373         }
 374
 375         $params = array($this->id);
 376
 377         $wheresql = '';
 378         if (!is_null($courseid)) {
 379             $wheresql = " AND {grade_items}.courseid = ? ";
 380             $params[] = $courseid;
 381         }
 382
 383         $selectadd = '';
 384         if ($items !== false) {
 385             $selectadd = ", {grade_items}.* ";
 386         }
 387
 388         $sql = "SELECT finalgrade $selectadd
 389                   FROM {grade_grades}, {grade_items}, {grade_outcomes}
 390                  WHERE {grade_outcomes}.id = {grade_items}.outcomeid
 391                    AND {grade_items}.id = {grade_grades}.itemid
 392                    AND {grade_outcomes}.id = ?
 393                    $wheresql";
 394
 395         $grades = $DB->get_records_sql($sql, $params);
 396         $retval = array();
 397
 398         if ($average !== false && count($grades) > 0) {
 399             $count = 0;
 400             $total = 0;
 401
 402             foreach ($grades as $k => $grade) {
 403                 // Skip null finalgrades
 404                 if (!is_null($grade->finalgrade)) {
 405                     $total += $grade->finalgrade;
 406                     $count++;
 407                 }
 408                 unset($grades[$k]->finalgrade);
 409             }
 410
 411             $retval['avg'] = $total / $count;
 412         }
 413
 414         if ($items !== false) {
 415             foreach ($grades as $grade) {
 416                 $retval['items'][$grade->id] = new grade_item($grade);
 417             }
 418         }
 419
 420         return $retval;
 421     }
 422 }