lib/grouplib.php

   1 <?php  //$Id$
   2
   3 /**
   4  * No groups used?
   5  */
   6 define('NOGROUPS', 0);
   7
   8 /**
   9  * Groups used?
  10  */
  11 define('SEPARATEGROUPS', 1);
  12
  13 /**
  14  * Groups visible?
  15  */
  16 define('VISIBLEGROUPS', 2);
  17
  18
  19 /**
  20  * Determines if a group with a given groupid exists.
  21  * @param int $groupid The groupid to check for
  22  * @return boolean True if the group exists, false otherwise or if an error
  23  * occurred.
  24  */
  25 function groups_group_exists($groupid) {
  26     return record_exists('groups', 'id', $groupid);
  27 }
  28
  29 /**
  30  * Gets the name of a group with a specified id
  31  * @param int $groupid The id of the group
  32  * @return string The name of the group
  33  */
  34 function groups_get_group_name($groupid) {
  35     return get_field('groups', 'name', 'id', $groupid);
  36 }
  37
  38 /**
  39  * Returns the groupid of a group with the name specified for the course.
  40  * Group names should be unique in course
  41  * @param int $courseid The id of the course
  42  * @param string $name name of group (without magic quotes)
  43  * @return int $groupid
  44  */
  45 function groups_get_group_by_name($courseid, $name) {
  46     if ($groups = get_records_select('groups', "courseid=$courseid AND name='".addslashes($name)."'")) {
  47         return key($groups);
  48     }
  49     return false;
  50 }
  51
  52 /**
  53  * Returns the groupingid of a grouping with the name specified for the course.
  54  * Grouping names should be unique in course
  55  * @param int $courseid The id of the course
  56  * @param string $name name of group (without magic quotes)
  57  * @return int $groupid
  58  */
  59 function groups_get_grouping_by_name($courseid, $name) {
  60     if ($groupings = get_records_select('groupings', "courseid=$courseid AND name='".addslashes($name)."'")) {
  61         return key($groupings);
  62     }
  63     return false;
  64 }
  65
  66 /**
  67  * Get the group object
  68  * @param groupid ID of the group.
  69  * @return group object
  70  */
  71 function groups_get_group($groupid) {
  72     return get_record('groups', 'id', $groupid);
  73 }
  74
  75 /**
  76  * Gets array of all groups in a specified course.
  77  * @param int $courseid The id of the course.
  78  * @param int $userid optional user id, returns only groups of the user.
  79  * @param int $groupingid optional returns only groups in the specified grouping.
  80  * @return array | false Returns an array of the group IDs or false if no records
  81  * or an error occurred.
  82  */
  83 function groups_get_all_groups($courseid, $userid=0, $groupingid=0) {
  84     global $CFG;
  85
  86     // groupings are ignored when not enabled
  87     if (empty($CFG->enablegroupings)) {
  88         $groupingid = 0;
  89     }
  90
  91     if (!empty($userid)) {
  92         $userfrom  = ", {$CFG->prefix}groups_members gm";
  93         $userwhere = "AND g.id = gm.groupid AND gm.userid = '$userid'";
  94     } else {
  95         $userfrom  = "";
  96         $userwhere = "";
  97     }
  98
  99     if (!empty($groupingid)) {
 100         $groupingfrom  = ", {$CFG->prefix}groupings_groups gg";
 101         $groupingwhere = "AND g.id = gg.groupid AND gg.groupingid = '$groupingid'";
 102     } else {
 103         $groupingfrom  = "";
 104         $groupingwhere = "";
 105     }
 106
 107     return get_records_sql("SELECT g.*
 108                               FROM {$CFG->prefix}groups g $userfrom $groupingfrom
 109                              WHERE g.courseid = '$courseid' $userwhere $groupingwhere
 110                           ORDER BY name ASC");
 111 }
 112
 113 /**
 114  * Determines if the user is a member of the given group.
 115  *
 116  * @uses $USER If $userid is null, use the global object.
 117  * @param int $groupid The group to check for membership.
 118  * @param int $userid The user to check against the group.
 119  * @return boolean True if the user is a member, false otherwise.
 120  */
 121 function groups_is_member($groupid, $userid=null) {
 122     global $USER;
 123
 124     if (!$userid) {
 125         $userid = $USER->id;
 126     }
 127
 128     return record_exists('groups_members', 'groupid', $groupid, 'userid', $userid);
 129 }
 130
 131 /**
 132  * Determines if current or specified is member of any active group in activity
 133  * @param object $cm coruse module object
 134  * @param int $userid id of user, null menas $USER->id
 135  * @return booelan true if user member of at least one group used in activity
 136  */
 137 function groups_has_membership($cm, $userid=null) {
 138     global $CFG, $USER;
 139
 140     static $cache = array();
 141
 142     // groupings are ignored when not enabled
 143     if (empty($CFG->enablegroupings)) {
 144         $cm->groupingid = 0;
 145     }
 146
 147     if (empty($userid)) {
 148         $userid = $USER->id;
 149     }
 150
 151     $cachekey = $userid.'|'.$cm->course.'|'.$cm->groupingid;
 152     if (isset($cache[$cachekey])) {
 153         return($cache[$cachekey]);
 154     }
 155
 156     if ($cm->groupingid) {
 157         // find out if member of any group in selected activity grouping
 158         $sql = "SELECT 'x'
 159                   FROM {$CFG->prefix}groups_members gm, {$CFG->prefix}groupings_groups gg
 160                  WHERE gm.userid = $userid AND gm.groupid = gg.groupid AND gg.groupingid = {$cm->groupingid}";
 161
 162     } else {
 163         // no grouping used - check all groups in course
 164         $sql = "SELECT 'x'
 165                   FROM {$CFG->prefix}groups_members gm, {$CFG->prefix}groups g
 166                  WHERE gm.userid = $userid AND gm.groupid = g.id AND g.courseid = {$cm->course}";
 167     }
 168
 169     $cache[$cachekey] = record_exists_sql($sql);
 170
 171     return $cache[$cachekey];
 172 }
 173
 174 /**
 175  * Returns the users in the specified group.
 176  * @param int $groupid The groupid to get the users for
 177  * @param int $fields The fields to return
 178  * @param int $sort optional sorting of returned users
 179  * @return array | false Returns an array of the users for the specified
 180  * group or false if no users or an error returned.
 181  */
 182 function groups_get_members($groupid, $fields='u.*', $sort='lastname ASC') {
 183     global $CFG;
 184
 185     return get_records_sql("SELECT $fields
 186                               FROM {$CFG->prefix}user u, {$CFG->prefix}groups_members gm
 187                              WHERE u.id = gm.userid AND gm.groupid = '$groupid'
 188                           ORDER BY $sort");
 189 }
 190
 191
 192 /**
 193  * Returns the users in the specified grouping.
 194  * @param int $groupingid The groupingid to get the users for
 195  * @param int $fields The fields to return
 196  * @param int $sort optional sorting of returned users
 197  * @return array | false Returns an array of the users for the specified
 198  * group or false if no users or an error returned.
 199  */
 200 function groups_get_grouping_members($groupingid, $fields='u.*', $sort='lastname ASC') {
 201     global $CFG;
 202
 203     return get_records_sql("SELECT $fields
 204                               FROM {$CFG->prefix}user u
 205                                 INNER JOIN {$CFG->prefix}groups_members gm ON u.id = gm.userid
 206                                 INNER JOIN {$CFG->prefix}groupings_groups gg ON gm.groupid = gg.groupid
 207                              WHERE  gg.groupingid = $groupingid
 208                           ORDER BY $sort");
 209 }
 210
 211 /**
 212  * Returns effective groupmode used in activity, course setting
 213  * overrides activity setting if groupmodeforce enabled.
 214  * @return integer group mode
 215  */
 216 function groups_get_activity_groupmode($cm) {
 217     global $COURSE;
 218
 219     // get course object (reuse COURSE if possible)
 220     if ($cm->course == $COURSE->id) {
 221         $course = $COURSE;
 222     } else {
 223         if (!$course = get_record('course', 'id', $cm->course)) {
 224             error('Incorrect course id in cm');
 225         }
 226     }
 227
 228     return empty($course->groupmodeforce) ? $cm->groupmode : $course->groupmode;
 229 }
 230
 231 /**
 232  * Print group menu selector for activity.
 233  * @param object $cm course module object
 234  * @param string $urlroot return address
 235  * @param boolean $return return as string instead of printing
 236  * @return mixed void or string depending on $return param
 237  */
 238 function groups_print_activity_menu($cm, $urlroot, $return=false) {
 239     global $CFG, $USER;
 240
 241     // groupings are ignored when not enabled
 242     if (empty($CFG->enablegroupings)) {
 243         $cm->groupingid = 0;
 244     }
 245
 246     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 247         if ($return) {
 248             return '';
 249         } else {
 250             return;
 251         }
 252     }
 253
 254     $context = get_context_instance(CONTEXT_MODULE, $cm->id);
 255     if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
 256         $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid); // any group in grouping (all if groupings not used)
 257     } else {
 258         $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid); // only assigned groups
 259     }
 260
 261     $activegroup = groups_get_activity_group($cm, true);
 262
 263     $groupsmenu = array();
 264     if (!$allowedgroups or $groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
 265         $groupsmenu[0] = get_string('allparticipants');
 266     }
 267
 268     if ($allowedgroups) {
 269         foreach ($allowedgroups as $group) {
 270             $groupsmenu[$group->id] = format_string($group->name);
 271         }
 272     }
 273
 274     if ($groupmode == VISIBLEGROUPS) {
 275         $grouplabel = get_string('groupsvisible');
 276     } else {
 277         $grouplabel = get_string('groupsseparate');
 278     }
 279
 280     if (count($groupsmenu) == 1) {
 281         $groupname = reset($groupsmenu);
 282         $output = $grouplabel.': '.$groupname;
 283     } else {
 284         $output = popup_form($urlroot.'&amp;group=', $groupsmenu, 'selectgroup', $activegroup, '', '', '', true, 'self', $grouplabel);
 285     }
 286
 287     $output = '<div class="groupselector">'.$output.'</div>';
 288
 289     if ($return) {
 290         return $output;
 291     } else {
 292         echo $output;
 293     }
 294 }
 295
 296 /**
 297  * Returns group active in activity, changes the group by default if 'group' page param present
 298  *
 299  * @param object $cm course module object
 300  * @param boolean $update change active group if group param submitted
 301  * @return mixed false if groups not used, int if groups used, 0 means all groups (access must be verified in SEPARATE mode)
 302  */
 303 function groups_get_activity_group($cm, $update=false) {
 304     global $CFG, $USER, $SESSION;
 305
 306     // groupings are ignored when not enabled
 307     if (empty($CFG->enablegroupings)) {
 308         $cm->groupingid = 0;
 309     }
 310
 311     if (!$groupmode = groups_get_activity_groupmode($cm)) {
 312         // NOGROUPS used
 313         return false;
 314     }
 315
 316     // innit activegroup array
 317     if (!array_key_exists('activegroup', $SESSION)) {
 318         $SESSION->activegroup = array();
 319     }
 320     if (!array_key_exists($cm->course, $SESSION->activegroup)) {
 321         $SESSION->activegroup[$cm->course] = array(SEPARATEGROUPS=>array(), VISIBLEGROUPS=>array());
 322     }
 323
 324     // grouping used the first time - add first user group as default
 325     if (!array_key_exists($cm->groupingid, $SESSION->activegroup[$cm->course][$groupmode])) {
 326         if ($usergroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid)) {
 327             $fistgroup = reset($usergroups);
 328             $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = $fistgroup->id;
 329         } else {
 330             // this happen when user not assigned into group in SEPARATEGROUPS mode or groups do not exist yet
 331             // mod authors must add extra checks for this when SEPARATEGROUPS mode used (such as when posting to forum)
 332             $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = 0;
 333         }
 334     }
 335
 336     // set new active group if requested
 337     $changegroup = optional_param('group', -1, PARAM_INT);
 338     if ($update and $changegroup != -1) {
 339         $context = get_context_instance(CONTEXT_MODULE, $cm->id);
 340
 341         if ($changegroup == 0) {
 342             // do not allow changing to all groups without accessallgroups capability
 343             if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
 344                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = 0;
 345             }
 346
 347         } else {
 348             // first make list of allowed groups
 349             if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {
 350                 $allowedgroups = groups_get_all_groups($cm->course, 0, $cm->groupingid); // any group in grouping (all if groupings not used)
 351             } else {
 352                 $allowedgroups = groups_get_all_groups($cm->course, $USER->id, $cm->groupingid); // only assigned groups
 353             }
 354
 355             if ($allowedgroups and array_key_exists($changegroup, $allowedgroups)) {
 356                 $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid] = $changegroup;
 357             }
 358         }
 359     }
 360
 361     return $SESSION->activegroup[$cm->course][$groupmode][$cm->groupingid];
 362 }
 363
 364 /**
 365  * Determine if a course module is currently visible to a user
 366  * @uses $USER If $userid is null, use the global object.
 367  * @param int $cm The course module
 368  * @param int $userid The user to check against the group.
 369  * @return boolean True if the user can view the course module, false otherwise.
 370  */
 371 function groups_course_module_visible($cm, $userid=null) {
 372     global $CFG, $USER;
 373
 374     if (empty($userid)) {
 375         $userid = $USER->id;
 376     }
 377     if (empty($CFG->enablegroupings)) {
 378         return(true);
 379     }
 380     if (empty($cm->groupmembersonly)) {
 381         return(true);
 382     }
 383     if (groups_has_membership($cm, $userid) || has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id), $userid)) {
 384         return(true);
 385     }
 386     return(false);
 387 }
 388
 389 ?>