moodle/group/lib/modulelib.php

429 lines
16 KiB
PHP

<?php
/**
* modulelib.php
*
* This file contains functions to be used by modules to support groups. More
* documentation is available on the Developer's Notes section of the Moodle
* wiki.
*
* For queries, suggestions for improvements etc. please post on the Groups
* forum on the moodle.org site.
*
* @copyright &copy; 2006 The Open University
* @author J.White AT open.ac.uk
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
* @package groups
*/
/*
* (OLD) Permission types
*
* There are six types of permission that a user can hold for a particular
* group - 'student view', 'student contribute', 'teacher view',
* 'teacher contribute', 'view members list' and 'view group existence'.
*
* A particular user need not to be a member of the group to have a specific
* permission and may have more than one permission type. The permission that a
* particular user has for a group used by an particular instance of the module
* depends on whether the student is a teacher or student for the course and on
* the settings for the set of groups (the 'grouping') being used by the
* instance of the module
*
* It is up to each module to decide how to interpret the different permission
* types. The only exception is with 'view members list' and 'view group
* existence'. The former means that the user can view the members of the group
* while the latter means that the user can view information such as the group
* name and description. It is possible that a user may have 'view members list'
* permission without 'view group existence' permission - the members would just
* appear as the other users on the course.
*
* Permission types can be combined with boolean expressions where they are used
* if necessary.
*
* @name GROUPS_STUDENT Either 'student view' or 'student contribute' permission
* @name GROUPS_TEACHER Either 'teacher view' or 'teacher contribute' permission
* @name GROUPS_VIEW Either 'teacher view' or 'student view' permission
* @name GROUPS_CONTRIBUTE Either 'teacher contribute' or 'student contribute'
* permission
* @name GROUPS_VIEW_GROUP_EXISTENCE 'view group existence' permission
* @name GROUPS_VIEW_MEMBERS_LIST 'view members list' permission
* @name GROUPS_STUDENT_VIEW 'student view' permission
* @name GROUPS_STUDENT_CONTRIBUTE 'student contribute' permission
* @name GROUPS_TEACHER_VIEW 'teacher view' permission
* @name GROUPS_TEACHER_CONTRIBUTE 'teacher contribute' permission
*/
define('GROUPS_STUDENT', 1);
define('GROUPS_TEACHER', 2);
define('GROUPS_VIEW', 4);
define('GROUPS_CONTRIBUTE', 8);
define('GROUPS_VIEW_GROUP_EXISTENCE', 16);
define('GROUPS_VIEW_MEMBERS_LIST', 48);
define('GROUPS_STUDENT_VIEW', 5);
define('GROUPS_STUDENT_CONTRIBUTE', 9);
define('GROUPS_TEACHER_VIEW', 6);
define('GROUPS_TEACHER_CONTRIBUTE', 10);
/**
* Indicates if the instance of the module has been set up by an editor of the
* course to use groups. This functionality can also be obtained using the
* groups_m_get_groups() function, however it is sufficiently commonly needed
* that this separate function has been provided and should be used instead.
* @param int $cmid The id of the module instance
* @return boolean True if the instance is set up to use groups, false otherwise
*/
function groups_m_uses_groups($cmid) {
$usesgroups = false;
$groupingid = groups_db_get_groupingid($cmid);
if (!$groupingid) {
$usesgroups = true;
}
return $usesgroups;
}
/**
* Prints a dropdown box to enable a user to select between the groups for the
* module instance of which they are a member. If a user belongs to 0 or 1
* groups, no form is printed. The dropdown box belongs to a form and when a
* user clicks on the box this form is automatically submitted so that the page
* knows about the change.
* @param int $cmid The id of the module instance
* @param string $urlroot The url of the page - this is necessary so the form
* can submit to the correct page.
* @param int $permissiontype - see note on permissiontypes above.
* @return boolean True unless an error occurred or the module instance does not
* use groups in which case returns false.
*/
function groups_m_print_group_selector($cmid, $urlroot, $permissiontype) {
// Get the groups for the cmid
// Produce an array to put into the $groupsmenu array.
// Add an all option if necessary.
$groupids = groups_module_get_groups_for_current_user($cmid, $permissiontype);
// Need a line to check if current group selected.
if ($groupids) {
$currentgroup = groups_module_get_current_group($cmid);
if ($allgroupsoption) {
$groupsmenu[0] = get_string('allparticipants');
}
foreach ($groupids as $groupid) {
$groupsmenu[$groupid] = groups_get_group_name($groupid);
popup_form($urlroot.'&amp;group=', $groupsmenu, 'selectgroup',
$currentgroup, '', '', '', false, 'self');
}
}
}
/**
* Gets the group that a student has selected from the drop-down menu printed
* by groups_m_print_group_selector and checks that the student has the
* specified permission for the group and that the group is one of the groups
* assigned for this module instance.
*
* Groups selected are saved between page changes within the module instance but
* not necessarily if the user leaves the instance e.g. returns to the main
* course page. If the selector has not been printed anywhere during the user's
* 'visit' to the module instance, then the function returns false. This means
* that you need to be particularly careful about pages that might be
* bookmarked by the user.
*
* @uses $USER
* @param int $cmid The id of the module instance
* @param int $permissiontype The permission type - see note on permission types
* above
* @param int $userid The id of the user, defaults to the current user
* @return boolean True if no error occurred, false otherwise.
*
* TO DO - make this and other functions default to current user
*/
function groups_m_get_selected_group($cmid, $permissiontype, $userid) {
$currentgroup = optional_param('group');
if (!$currentgroup) {
$groupids = groups_get_groups_for_user();
}
// Get it from the session variable, otherwise get it from the form, otherwise
// Get it from the database as the first group.
// Then set the group in the session variable to make it easier to get next time.
}
/**
* Gets an array of the group IDs of all groups for the user in this course module.
* @uses $USER
* @param object $cm The course-module object.
* @param int $userid The ID of the user.
* @return array An array of group IDs, or false.
*/
function groups_m_get_groups_for_user($cm, $userid) {
//echo 'User'; print_object($cm);
$groupingid = groups_get_grouping_for_coursemodule($cm);
if (!$groupingid || GROUP_NOT_IN_GROUPING == $groupingid) {
return false;
}
if (!isset($cm->course) || !groupmode($cm->course, $cm)) {
return false;
}
elseif (GROUP_ANY_GROUPING == $groupingid) {
return groups_get_groups_for_user($userid, $cm->course);
}
return groups_get_groups_for_user_in_grouping($userid, $groupingid);
}
/**
* Get the ID of the first group for the global $USER in the course module.
* Replaces legacylib function 'mygroupid'.
* @uses $USER
* @param $cm A course module object.
* @return int A single group ID for this user.
*/
function groups_m_get_my_group($cm) {
global $USER;
$groupids = groups_m_get_groups_for_user($cm, $USER->id);
if (!$groupids || count($groupids) == 0) {
return 0;
}
return array_shift($groupids);
}
/**
* Indicates if a specified user has a particular type of permission for a
* particular group for this module instance.
* @uses $USER
* @param int $cmid The id of the module instance. This is necessary because the
* same group can be used in different module instances with different
* permission setups.
* @param int $groupid The id of the group
* @param int $permissiontype The permission type - see note on permission types
* above
* @userid int $userid The id of the user, defaults to the current user
* @return boolean True if the user has the specified permission type, false
* otherwise or if an error occurred.
*/
function groups_m_has_permission($cm, $groupid, $permissiontype, $userid = null) {
if (!$userid) {
global $USER;
$userid = $USER->id;
}
$groupingid = groups_get_grouping_for_coursemodule($cm);
if (!$groupingid || !is_object($cm) || !isset($cm->course)) {
return false;
}
$courseid = $cm->course;
$isstudent = isstudent($courseid, $userid);
$isteacher = isteacher($courseid, $userid);
$groupmember = groups_is_member($groupid, $userid);
$memberofsomegroup = groups_is_member_of_some_group_in_grouping($userid, $groupingid);
$groupingsettings = groups_get_grouping_settings($groupingid);
$viewowngroup = $groupingsettings->viewowngroup;
$viewallgroupsmembers = $groupingsettings->viewallgroupmembers;
$viewallgroupsactivities = $groupingsettings->viewallgroupsactivities;
$teachersgroupsmark = $groupingsettings->teachersgroupsmark;
$teachersgroupsview = $groupingsettings->teachersgroupsview;
$teachersgroupmark = $groupingsettings->teachersgroupmark;
$teachersgroupview = $groupingsettings->teachersgroupview;
$teachersoverride = $groupingsettings->teachersoverride;
$permission = false;
switch ($permissiontype) {
case 'view':
if (($isstudent and $groupmember) or
($isteacher and $groupmember) or
($isstudent and $viewallgroupsactivities) or
($isteacher and !$teachersgroupview) or
($isteacher and !$memberofsomegroup and $teachersoverride)) {
$permission = true;
}
break;
case 'studentcontribute':
if (($isstudent and $groupmember) or
($isteacher and $groupmember) or
($isteacher and !$memberofsomegroup and $teachersoverride)) {
$permission = true;
}
break;
case 'teachermark':
if (($isteacher and $groupmember) or
($isteacher and !$teachersgroupmark) or
($isteacher and !$memberofsomegroup and $teachersoverride)) {
$permission = true;
}
break;
case 'viewmembers':
if (($isstudent and $groupmember and $viewowngroup) or
($isstudent and $viewallgroupsmembers) or
($isteacher and $groupmember) or
($isteacher and !$teachersgroupview) or
($isteacher and !$memberofsomegroup and $teachersoverride) or
$isteacheredit) {
$permission = true;
}
break;
}
return $permission;
}
/**
* Gets an array of members of a group that have a particular permission type
* for this instance of the module and that are enrolled on the course that
* the module instance belongs to.
*
* @param int $cmid The id of the module instance. This is necessary because the
* same group can be used in different module instances with different
* permission setups.
* @param int $groupid The id of the group
* @param int $permissiontype The permission type - see note on permission types
* above
* @return array An array containing the ids of the users with the specified
* permission.
*/
function groups_m_get_members_with_permission($cmid, $groupid,
$permissiontype) {
// Get all the users as $userid
$validuserids = array();
foreach($validuserids as $userid) {
$haspermission = groups_m_has_permission($cmid, $groupid,
$permissiontype, $userid);
if ($haspermission) {
array_push($validuserids, $userid);
}
}
return $validuserids;
}
/**
* Gets the group object associated with a group id. This group object can be
* used to get information such as the name of the group and the file for the
* group icon if it exists. (Look at the groups table in the database to see
* the fields).
* @param int $groupid The id of the group
* @return group The group object
*/
function groups_m_get_group($groupid) {
return groups_db_m_get_group($groupid);
}
/**
* Gets the groups for the module instance. In general, you should use
* groups_m_get_groups_for_user, however this function is provided for
* circumstances where this function isn't sufficient for some reason.
* @param int $cmid The id of the module instance.
* @return array An array of the ids of the groups for the module instance
*/
function groups_m_get_groups($cmid) {
$groupingid = groups_db_get_groupingid($cmid);
$groupids = groups_get_groups_in_grouping($groupingid);
return $groupids;
}
/**
* Gets the members of group that are enrolled on the course that the specified
* module instance belongs to.
* @param int $cmid The id of the module instance
* @param int $groupid The id of the group
* @return array An array of the userids of the members.
*/
function groups_m_get_members($cmid, $groupid) {
$userids = groups_get_members($groupid, $membertype);
if (!$userids) {
$memberids = false;
} else {
// Check if each user is enrolled on the course @@@ TO DO
}
return $memberids;
}
/**
* Stores a current group in the user's session, if not already present.
*
* Current group applies to all modules in the current course that share
* a grouping (or use no grouping).
*
* This function allows the user to change group if they want, but it
* checks they have permissions to access the new group and calls error()
* otherwise.
* @param object $cm Course-module object
* @param int $groupmode Group mode
* @param int $changegroup If specified, user wants to change to this group
* @return Group ID
*/
function groups_m_get_and_set_current($cm, $groupmode, $changegroup=-1) {
// Check group mode is turned on
if (!$groupmode) {
return false;
}
// Get current group and return it if no change requested
$currentgroupid = groups_m_get_current($cm);
if ($changegroup<0) {
return $currentgroupid;
}
// Check 'all groups' access
$context = get_context_instance(CONTEXT_COURSE, $cm->course);
$allgroups = has_capability('moodle/site:accessallgroups', $context);
// 0 is a special case for 'all groups'.
if ($changegroup==0) {
if ($groupmode!=VISIBLEGROUPS && !$allgroups) {
error('You do not have access to view all groups');
}
} else { // Normal group specified
// Check group is in the course...
if (!groups_group_belongs_to_course($changegroup, $cm->course)) {
error('Requested group is not in this course.');
}
// ...AND in the right grouping if required...
if ($cm->groupingid && !groups_belongs_to_grouping($changegroup, $cm->groupingid)) {
print_object($cm);
print_object(groups_get_group($changegroup));
error('Requested group is not in this grouping.');
}
// ...AND user has access to all groups, or it's in visible groups mode, or
// user is a member.
if (!$allgroups &&
$groupmode != VISIBLEGROUPS && !groups_is_member($changegroup)) {
}
}
// OK, now remember this group in session
global $SESSION;
$SESSION->currentgroupinggroup[$cm->course][$cm->groupingid] = $changegroup;
return $changegroup;
}
/**
* Obtains the current group (see groups_m_get_and_set_current) either as an ID or object.
* @param object $cm Course-module object
* @param bool $full If true, returns group object rather than ID
* @return mixed Group ID (default) or object
*/
function groups_m_get_current($cm, $full=false) {
global $SESSION;
if (isset($SESSION->currentgroupinggroup[$cm->course][$cm->groupingid])) {
$currentgroup = $SESSION->currentgroupinggroup[$cm->course][$cm->groupingid];
} else {
global $USER;
if ($cm->groupingid) {
$mygroupids=groups_get_groups_for_user_in_grouping($USER->id, $cm->groupingid);
} else {
$mygroupids=groups_get_groups_for_user($USER->id, $cm->course);
}
if (!$mygroupids) {
return false;
}
$currentgroup = array_shift($mygroupids);
$SESSION->currentgroupinggroup[$cm->course][$cm->groupingid]=$currentgroup;
}
if ($full) {
return groups_groupid_to_group($currentgroup);
} else {
return $currentgroup;
}
}
?>