lib/grouplib.php

   1 <?php  //$Id$
   2
   3
   4 /**
   5  * Determines if a group with a given groupid exists.
   6  * @param int $groupid The groupid to check for
   7  * @return boolean True if the group exists, false otherwise or if an error
   8  * occurred.
   9  */
  10 function groups_group_exists($groupid) {
  11     return record_exists('groups', 'id', $groupid);
  12 }
  13
  14 /**
  15  * Gets the name of a group with a specified id
  16  * @param int $groupid The id of the group
  17  * @return string The name of the group
  18  */
  19 function groups_get_group_name($groupid) {
  20     return get_field('groups', 'name', 'id', $groupid);
  21 }
  22
  23 /**
  24  * Returns the groupid of a group with the name specified for the course.
  25  * Group names should be unique in course
  26  * @param int $courseid The id of the course
  27  * @param string $name name of group (without magic quotes)
  28  * @return int $groupid
  29  */
  30 function groups_get_group_by_name($courseid, $name) {
  31     if ($groups = get_records_select('groups', "courseid=$courseid AND name='".addslashes($name)."'")) {
  32         return key($groups);
  33     }
  34     return false;
  35 }
  36
  37 /**
  38  * Returns the groupingid of a grouping with the name specified for the course.
  39  * Grouping names should be unique in course
  40  * @param int $courseid The id of the course
  41  * @param string $name name of group (without magic quotes)
  42  * @return int $groupid
  43  */
  44 function groups_get_grouping_by_name($courseid, $name) {
  45     if ($groupings = get_records_select('groupings', "courseid=$courseid AND name='".addslashes($name)."'")) {
  46         return key($groupings);
  47     }
  48     return false;
  49 }
  50
  51 /**
  52  * Get the group object
  53  * @param groupid ID of the group.
  54  * @return group object
  55  */
  56 function groups_get_group($groupid) {
  57     return get_record('groups', 'id', $groupid);
  58 }
  59
  60 /**
  61  * Gets array of all groups in a specified course.
  62  * @param int $courseid The id of the course.
  63  * @param int $userid optional user id, returns only groups of the user.
  64  * @param int $groupingid optional returns only groups in the specified grouping.
  65  * @return array | false Returns an array of the group IDs or false if no records
  66  * or an error occurred.
  67  */
  68 function groups_get_all_groups($courseid, $userid=0, $groupingid=0) {
  69     global $CFG;
  70
  71     if (!empty($userid)) {
  72         $userfrom  = ", {$CFG->prefix}groups_members gm";
  73         $userwhere = "AND g.id = gm.groupid AND gm.userid = '$userid'";
  74     } else {
  75         $userfrom  = "";
  76         $userwhere = "";
  77     }
  78
  79     if (!empty($groupingid)) {
  80         $groupingfrom  = ", {$CFG->prefix}groupings_groups gg";
  81         $groupingwhere = "AND g.id = gg.groupid AND gg.groupingid = '$groupingid'";
  82     } else {
  83         $groupingfrom  = "";
  84         $groupingwhere = "";
  85     }
  86
  87     return get_records_sql("SELECT g.*
  88                               FROM {$CFG->prefix}groups g $userfrom $groupingfrom
  89                              WHERE g.courseid = '$courseid' $userwhere $groupingwhere
  90                           ORDER BY name ASC");
  91 }
  92
  93 /**
  94  * Determines if the user is a member of the given group.
  95  *
  96  * @uses $USER If $userid is null, use the global object.
  97  * @param int $groupid The group to check for membership.
  98  * @param int $userid The user to check against the group.
  99  * @return boolean True if the user is a member, false otherwise.
 100  */
 101 function groups_is_member($groupid, $userid=null) {
 102     global $USER;
 103
 104     if (!$userid) {
 105         $userid = $USER->id;
 106     }
 107
 108     return record_exists('groups_members', 'groupid', $groupid, 'userid', $userid);
 109 }
 110
 111 /**
 112  * Determines if current or specified is member of any active group in activity
 113  * @param object $cm coruse module object
 114  * @param int $userid id of user, null menas $USER->id
 115  * @return booelan true if user member of at least one group used in activity
 116  */
 117 function groups_has_membership($cm, $userid=null) {
 118     global $CFG, $USER;
 119
 120     if (empty($userid)) {
 121         $userid = $USER->id;
 122     }
 123
 124     if ($cm->groupingid) {
 125         // find out if member of any group in selected activity grouping
 126         $sql = "SELECT 'x'
 127                   FROM {$CFG->prefix}groups_members gm, {$CFG->prefix}groupings_groups gg
 128                  WHERE gm.userid = $userid AND gm.groupid = gg.groupid AND gg.groupingid = {$cm->groupingid}";
 129
 130     } else {
 131         // no grouping used - check all groups in course
 132         $sql = "SELECT 'x'
 133                   FROM {$CFG->prefix}groups_members gm, {$CFG->prefix}groups g
 134                  WHERE gm.userid = $userid AND gm.groupid = g.id AND g.courseid = {$cm->course}";
 135     }
 136
 137     return record_exists_sql($sql);
 138 }
 139
 140 /**
 141  * Returns the users in the specified group.
 142  * @param int $groupid The groupid to get the users for
 143  * @param int $sort optional sorting of returned users
 144  * @return array | false Returns an array of the users for the specified
 145  * group or false if no users or an error returned.
 146  */
 147 function groups_get_members($groupid, $sort='lastname ASC') {
 148     global $CFG;
 149
 150     return get_records_sql("SELECT u.*
 151                               FROM {$CFG->prefix}user u, {$CFG->prefix}groups_members gm
 152                              WHERE u.id = gm.userid AND gm.groupid = '$groupid'
 153                           ORDER BY $sort");
 154 }
 155
 156
 157
 158 ?>