classes/class.ilObjGroup.php

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<?php
/*
        +-----------------------------------------------------------------------------+
        | ILIAS open source                                                           |
        +-----------------------------------------------------------------------------+
        | Copyright (c) 1998-2001 ILIAS open source, University of Cologne            |
        |                                                                             |
        | This program is free software; you can redistribute it and/or               |
        | modify it under the terms of the GNU General Public License                 |
        | as published by the Free Software Foundation; either version 2              |
        | of the License, or (at your option) any later version.                      |
        |                                                                             |
        | This program is distributed in the hope that it will be useful,             |
        | but WITHOUT ANY WARRANTY; without even the implied warranty of              |
        | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               |
        | GNU General Public License for more details.                                |
        |                                                                             |
        | You should have received a copy of the GNU General Public License           |
        | along with this program; if not, write to the Free Software                 |
        | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. |
        +-----------------------------------------------------------------------------+
*/

//TODO: function getRoleId($groupRole) returns the object-id of grouprole

require_once "class.ilObject.php";

class ilObjGroup extends ilObject
{
        var $m_grpStatus;

        var $m_roleMemberId;

        var $m_roleAdminId;

        function ilObjGroup($a_id = 0,$a_call_by_reference = true)
        {
                global $tree;

                $this->tree =& $tree;

                $this->type = "grp";
                $this->ilObject($a_id,$a_call_by_reference);
                $this->setRegisterMode(true);
        }

        function join($a_user_id, $a_mem_role="")
        {
                global $rbacadmin;

                if (is_array($a_mem_role))
                {
                        foreach ($a_mem_role as $role)
                        {
                                $rbacadmin->assignUser($role,$a_user_id, false);
                        }
                }
                else
                {
                        $rbacadmin->assignUser($a_mem_role,$a_user_id, false);
                }

                ilObjUser::updateActiveRoles($a_user_id);
                return true;
        }

        function getDefaultMemberRole()
        {
                $local_group_Roles = $this->getLocalGroupRoles();

                return $local_group_Roles["il_grp_member_".$this->getRefId()];
        }

        function getDefaultAdminRole()
        {
                $local_group_Roles = $this->getLocalGroupRoles();

                return $local_group_Roles["il_grp_admin_".$this->getRefId()];
        }

        function addMember($a_user_id, $a_mem_role)
        {
                global $rbacadmin;

                if (isset($a_user_id) && isset($a_mem_role) )
                {
                        $this->join($a_user_id,$a_mem_role);
                        return true;
                }
                else
                {
                        $this->ilias->raiseError(get_class($this)."::addMember(): Missing parameters !",$this->ilias->error_obj->WARNING);
                        return false;
                }
        }

        function getNewRegistrations()
        {
                $appList = array();
                $q = "SELECT * FROM grp_registration WHERE grp_id=".$this->getId();
                $res = $this->ilias->db->query($q);

                while ($row = $res->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        array_push($appList,$row);
                }

                return ($appList) ? $appList : false;
        }

        function deleteApplicationListEntry($a_userId)
        {
                $q = "DELETE FROM grp_registration WHERE user_id=".$a_userId." AND grp_id=".$this->getId();
                $res = $this->ilias->db->query($q);
        }

        function leaveGroup()
        {
                global $rbacadmin, $rbacreview;

                $member_ids = $this->getGroupMemberIds();

                if (count($member_ids) <= 1 || !in_array($this->ilias->account->getId(), $member_ids))
                {
                        return 2;
                }
                else
                {
                        if (!$this->isAdmin($this->ilias->account->getId()))
                        {
                                $this->leave($this->ilias->account->getId());
                                $member = new ilObjUser($this->ilias->account->getId());
                                $member->dropDesktopItem($this->getRefId(), "grp");

                                return 0;
                        }
                        else if (count($this->getGroupAdminIds()) == 1)
                        {
                                return 1;
                        }
                }
        }

        function leave($a_user_id)
        {
                global $rbacadmin;

                $arr_groupRoles = $this->getMemberRoles($a_user_id);

                if (is_array($arr_groupRoles))
                {
                        foreach ($arr_groupRoles as $groupRole)
                        {
                                $rbacadmin->deassignUser($groupRole, $a_user_id);
                        }
                }
                else
                {
                        $rbacadmin->deassignUser($arr_groupRoles, $a_user_id);
                }

                ilObjUser::updateActiveRoles($a_user_id);

                return true;
        }

        function removeMember($a_user_id, $a_grp_id="")
        {
                if (isset($a_user_id) && isset($a_grp_id) && $this->isMember($a_user_id))
                {
                        if (count($this->getGroupMemberIds()) > 1)
                        {
                                if ($this->isAdmin($a_user_id) && count($this->getGroupAdminIds()) < 2)
                                {
                                        return "grp_err_administrator_required";
                                }
                                else
                                {
                                        $this->leave($a_user_id);
                                        $member = new ilObjUser($a_user_id);
                                        $member->dropDesktopItem($this->getRefId(), "grp");

                                        return "";
                                }
                        }
                        else
                        {
                                return "grp_err_last_member";
                        }
                }
                else
                {
                        $this->ilias->raiseError(get_class($this)."::removeMember(): Missing parameters !",$this->ilias->error_obj->WARNING);
                }
        }

        function getGroupMemberIds()
        {
                global $rbacadmin, $rbacreview;

                $usr_arr= array();

                $rol  = $this->getLocalGroupRoles();

                foreach ($rol as $value)
                {
                        foreach ($rbacreview->assignedUsers($value) as $member_id)
                        {
                                array_push($usr_arr,$member_id);
                        }
                }

                $mem_arr = array_unique($usr_arr);
                
                return $mem_arr ? $mem_arr : array();
        }
        
        function getGroupMemberData($a_mem_ids)
        {
                global $rbacadmin, $rbacreview, $ilBench, $ilDB;

                $usr_arr= array();
                
                $q = "SELECT login,firstname,lastname,title,usr_id,last_login ".
                         "FROM usr_data ".
                         "WHERE usr_id IN (".implode(',',$a_mem_ids).")";
                $r = $ilDB->query($q);
                
                while($row = $r->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        $mem_arr[] = array("id" => $row->usr_id,
                                                                "login" => $row->login,
                                                                "firstname" => $row->firstname,
                                                                "lastname" => $row->lastname,
                                                                "last_login" => $row->last_login
                                                                );
                }

                return $mem_arr ? $mem_arr : array();
        }

        function getCountMembers()
        {
                return count($this->getGroupMemberIds());
        }

        function getGroupAdminIds($a_grpId="")
        {
                global $rbacreview;

                if (!empty($a_grpId))
                {
                        $grp_id = $a_grpId;
                }
                else
                {
                        $grp_id = $this->getRefId();
                }

                $usr_arr = array();
                $roles = $this->getDefaultGroupRoles($this->getRefId());

                foreach ($rbacreview->assignedUsers($this->getDefaultAdminRole()) as $member_id)
                {
                        array_push($usr_arr,$member_id);
                }

                return $usr_arr;
        }

        function getDefaultGroupRoles($a_grp_id="")
        {
                global $rbacadmin, $rbacreview;

                if (strlen($a_grp_id) > 0)
                {
                        $grp_id = $a_grp_id;
                }
                else
                {
                        $grp_id = $this->getRefId();
                }

                $rolf      = $rbacreview->getRoleFolderOfObject($grp_id);
                $role_arr  = $rbacreview->getRolesOfRoleFolder($rolf["ref_id"]);

                foreach ($role_arr as $role_id)
                {
                        $role_Obj =& $this->ilias->obj_factory->getInstanceByObjId($role_id);

                        $grp_Member ="il_grp_member_".$grp_id;
                        $grp_Admin  ="il_grp_admin_".$grp_id;

                        if (strcmp($role_Obj->getTitle(), $grp_Member) == 0 )
                        {
                                $arr_grpDefaultRoles["grp_member_role"] = $role_Obj->getId();
                        }

                        if (strcmp($role_Obj->getTitle(), $grp_Admin) == 0)
                        {
                                $arr_grpDefaultRoles["grp_admin_role"] = $role_Obj->getId();
                        }
                }

                return $arr_grpDefaultRoles;
        }

        function getLocalGroupRoles()
        {
                global $rbacadmin,$rbacreview;
                
                if (empty($this->local_roles))
                {
                        $this->local_roles = array();
                        $rolf      = $rbacreview->getRoleFolderOfObject($this->getRefId());
                        $role_arr  = $rbacreview->getRolesOfRoleFolder($rolf["ref_id"]);

                        foreach ($role_arr as $role_id)
                        {
                                if ($rbacreview->isAssignable($role_id,$rolf["ref_id"]) == true)
                                {
                                        $role_Obj =& $this->ilias->obj_factory->getInstanceByObjId($role_id);
                                        $this->local_roles[$role_Obj->getTitle()] = $role_Obj->getId();
                                }
                        }
                }
                
                return $this->local_roles;
        }

        function getGrpStatusClosedTemplateId()
        {
                $q = "SELECT obj_id FROM object_data WHERE type='rolt' AND title='il_grp_status_closed'";
                $res = $this->ilias->db->query($q);
                $row = $res->fetchRow(DB_FETCHMODE_ASSOC);

                return $row["obj_id"];
        }

        function getGrpStatusOpenTemplateId()
        {
                $q = "SELECT obj_id FROM object_data WHERE type='rolt' AND title='il_grp_status_open'";
                $res = $this->ilias->db->query($q);
                $row = $res->fetchRow(DB_FETCHMODE_ASSOC);

                return $row["obj_id"];
        }
        
        function setRegistrationFlag($a_regFlag="")
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);

                if (!isset($a_regFlag))
                {
                        $a_regFlag = 0;
                }

                if ($res->numRows() == 0)
                {
                        $q = "INSERT INTO grp_data (grp_id, register) VALUES(".$this->getId().",".$a_regFlag.")";
                        $res = $this->ilias->db->query($q);
                }
                else
                {
                        $q = "UPDATE grp_data SET register=".$a_regFlag." WHERE grp_id=".$this->getId()."";
                        $res = $this->ilias->db->query($q);
                }
        }

        function getRegistrationFlag()
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);
                $row = $res->fetchRow(DB_FETCHMODE_ASSOC);

                return $row["register"];
        }

        function getPassword()
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);
                $row = $res->fetchRow(DB_FETCHMODE_ASSOC);

                return $row["password"];
        }
        
        function setPassword($a_password="")
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);

                if ($res->numRows() == 0)
                {
                        $q = "INSERT INTO grp_data (grp_id, password) VALUES(".$this->getId().",'".$a_password."')";
                        $res = $this->ilias->db->query($q);
                }
                else
                {
                        $q = "UPDATE grp_data SET password='".$a_password."' WHERE grp_id=".$this->getId()."";
                        $res = $this->ilias->db->query($q);
                }
        }

        function setExpirationDateTime($a_date)
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);
                $date = ilFormat::input2date($a_date);

                if ($res->numRows() == 0)
                {
                        $q = "INSERT INTO grp_data (grp_id, expiration) VALUES(".$this->getId().",'".$date."')";
                        $res = $this->ilias->db->query($q);
                }
                else
                {
                        $q = "UPDATE grp_data SET expiration='".$date."' WHERE grp_id=".$this->getId()."";
                        $res = $this->ilias->db->query($q);
                }
        }

        function getExpirationDateTime()
        {
                $q = "SELECT * FROM grp_data WHERE grp_id='".$this->getId()."'";
                $res = $this->ilias->db->query($q);
                $row = $res->fetchRow(DB_FETCHMODE_ASSOC);
                $datetime = $row["expiration"];
                $date = ilFormat::fdateDB2dateDE($datetime);
                $time = substr($row["expiration"], -8);
                $datetime = array(0=>$date, 1=>$time);

                return $datetime;
        }

        function registrationPossible()
        {
                $datetime = $this->getExpirationDateTime();
                $today_date = ilFormat::getDateDE();
                $today_time = date("H:i:s");
       
                $ts_exp_date = ilFormat::dateDE2timestamp($datetime[0]);
                $ts_today_date = ilFormat::dateDE2timestamp($today_date);
        
                $ts_exp_time = substr($datetime[1], 0, 2).
                                                substr($datetime[1], 3, 2).
                                                substr($datetime[1], 6, 2);
                
                $ts_today_time = substr($today_time, 0, 2).
                                                substr($today_time, 3, 2).
                                                substr($today_time, 6, 2);
                
                if ($ts_today_date < $ts_exp_date) 
                {
                        return true;
                }
                elseif (($ts_today_date == $ts_exp_date) and (strcmp($ts_exp_time,$ts_today_time) >= 0)) 
                {
                        return true;
                }
                else 
                {
                        return false;
                }
        }

        function setGroupStatus($a_grpStatus)
        {
                global $rbacadmin, $rbacreview, $rbacsystem;

                //get Rolefolder of group
                $rolf_data = $rbacreview->getRoleFolderOfObject($this->getRefId());

                //define all relevant roles that rights are needed to be changed
                $arr_parentRoles = $rbacreview->getParentRoleIds($this->getRefId());
                $arr_relevantParentRoleIds = array_diff(array_keys($arr_parentRoles),$this->getDefaultGroupRoles());

                //group status open (aka public) or group status closed
                if ($a_grpStatus == 0 || $a_grpStatus == 1)
                {
                        if ($a_grpStatus == 0)
                        {
                                $template_id = $this->getGrpStatusOpenTemplateId();
                        } else {
                                $template_id = $this->getGrpStatusClosedTemplateId();
                        }
                        //get defined operations from template
                        $template_ops = $rbacreview->getOperationsOfRole($template_id, 'grp', ROLE_FOLDER_ID);

                        foreach ($arr_relevantParentRoleIds as $parentRole)
                        {
                                $granted_permissions = array();

                                // Delete the linked role for the parent role
                                // (just in case if it already exists).
                                $rbacadmin->deleteLocalRole($parentRole,$rolf_data["child"]);

                                // Grant permissions on the group object for 
                                // the parent role. In the foreach loop we
                                // compute the intersection of the role     
                                // template il_grp_status_open/_closed and the 
                                // permission template of the parent role.
                                $current_ops = $rbacreview->getRoleOperationsOnObject($parentRole, $this->getRefId());
                                $rbacadmin->revokePermission($this->getRefId(), $parentRole);
                                foreach ($template_ops as $template_op) 
                                {
                                        if (in_array($template_op,$current_ops)) 
                                        {
                                                array_push($granted_permissions,$template_op);
                                        }
                                }
                                if (!empty($granted_permissions))
                                {
                                        $rbacadmin->grantPermission($parentRole, $granted_permissions, $this->getRefId());
                                }

                                // Create a linked role for the parent role and
                                // initialize it with the intersection of 
                                // il_grp_status_open/_closed and the permission
                                // template of the parent role
                                $rbacadmin->copyRolePermissionIntersection(
                                        $template_id, ROLE_FOLDER_ID, 
                                        $parentRole, $arr_parentRoles[$parentRole]['parent'], 
                                        $rolf_data["child"], $parentRole
                                );      
                                $rbacadmin->assignRoleToFolder($parentRole,$rolf_data["child"],"false");
                        }//END foreach
                }
        }

        function getGroupStatus()
        {
                global $rbacsystem,$rbacreview;

                $role_folder = $rbacreview->getRoleFolderOfObject($this->getRefId());
                $local_roles = $rbacreview->getRolesOfRoleFolder($role_folder["ref_id"]);

                //get Rolefolder of group
                $rolf_data = $rbacreview->getRoleFolderOfObject($this->getRefId());
                //get all relevant roles
                $arr_globalRoles = array_diff($local_roles, $this->getDefaultGroupRoles());

                //if one global role has no permission to join the group is officially closed !
                foreach ($arr_globalRoles as $globalRole)
                {
                        $ops_of_role = $rbacreview->getOperationsOfRole($globalRole,"grp", ROLE_FOLDER_ID);

                        if ($rbacsystem->checkPermission($this->getRefId(), $globalRole ,"join"))
                        {
                                return 0;
                        }
                }

                return 1;
        }

        function getMemberRoles($a_user_id)
        {
                global $rbacadmin, $rbacreview,$ilBench;

                $ilBench->start("Group", "getMemberRoles");

                $arr_assignedRoles = array();

                $arr_assignedRoles = array_intersect($rbacreview->assignedRoles($a_user_id),$this->getLocalGroupRoles());

                $ilBench->stop("Group", "getMemberRoles");

                return $arr_assignedRoles;
        }
        
        function getMemberRolesTitle($a_user_id)
        {
                global $ilDB,$ilBench;

                $ilBench->start("Group", "getMemberRolesTitle");
                
                $str_member_roles ="";

                $q = "SELECT title ".
                         "FROM object_data ".
                         "LEFT JOIN rbac_ua ON object_data.obj_id=rbac_ua.rol_id ".
                         "WHERE object_data.type = 'role' ".
                         "AND rbac_ua.usr_id = ".$ilDB->quote($a_user_id)." ".
                         "AND rbac_ua.rol_id IN (".implode(',',$this->getLocalGroupRoles()).")";

                $r = $ilDB->query($q);

                while($row = $r->fetchRow(DB_FETCHMODE_ASSOC))
                {
                        $str_member_roles .= $row["title"].", ";
                }

                $ilBench->stop("Group", "getMemberRolesTitle");
                                
                return substr($str_member_roles,0,-2);
        }
        
        function setMemberStatus($a_user_id, $a_member_role)
        {
                if (isset($a_user_id) && isset($a_member_role))
                {
                        $this->removeMember($a_user_id);
                        $this->addMember($a_user_id, $a_member_role);
                }
        }

        function isMember($a_userId = "")
        {
                if (strlen($a_userId) == 0)
                {
                        $user_id = $this->ilias->account->getId();
                }
                else 
                {
                        $user_id = $a_userId;
                }
                
                if ($this->getType() == "grp")
                {

                        $arr_members = $this->getGroupMemberIds();

                        if (in_array($user_id, $arr_members))
                        {
                                return true;
                        }
                        else
                        {
                                return false;
                        }
                }
        }

        function isAdmin($a_userId)
        {
                global $rbacreview;

                $grp_Roles = $this->getDefaultGroupRoles();

                if (in_array($a_userId,$rbacreview->assignedUsers($grp_Roles["grp_admin_role"])))
                {
                        return true;
                }
                else
                {
                        return false;
                }
        }

        function ilClone($a_parent_ref)
        {
                global $rbacadmin;

                // always call parent ilClone function first!!
                $new_ref_id = parent::ilClone($a_parent_ref);
                
                // get object instance of cloned group
                $groupObj =& $this->ilias->obj_factory->getInstanceByRefId($new_ref_id);
                
                // find a free number
                for ($n = 1;$n < 99;$n++)
                {
                        $groupname_copy = $groupObj->getTitle()."_(copy_".$n.")";

                        if (!ilUtil::groupNameExists($groupname_copy))
                        {
                                $groupObj->setTitle($groupname_copy);
                                $groupObj->update();
                                break;
                        }
                }

                // setup rolefolder & default local roles (admin & member)
                $roles = $groupObj->initDefaultRoles();

                // ...finally assign groupadmin role to creator of group object
                $rbacadmin->assignUser($roles[0], $groupObj->getOwner(), "n");
                ilObjUser::updateActiveRoles($groupObj->getOwner());

                // TODO: function getGroupStatus returns integer but setGroupStatus expects a string.
                // I disabled this function. Please investigate
                // shofmann@databay.de  4.7.03
                // copy group status
                // 0=public/visible for all,1=closed/invisible for all
                $groupObj->setGroupStatus($this->getGroupStatus());

                // always destroy objects in ilClone method because clone() is recursive and creates instances for each object in subtree!
                unset($groupObj);
                unset($rfoldObj);
                unset($roleObj);

                // ... and finally always return new reference ID!!
                return $new_ref_id;
        }

        function delete()
        {
                // always call parent delete function first!!
                if (!parent::delete())
                {
                        return false;
                }
                
                $query = "DELETE FROM grp_data WHERE grp_id=".$this->getId();
                $this->ilias->db->query($query);

                return true;
        }

        function initDefaultRoles()
        {
                global $rbacadmin, $rbacreview;

                // create a local role folder
                $rfoldObj =& $this->createRoleFolder();

                // ADMIN ROLE
                // create role and assign role to rolefolder...
                $roleObj = $rfoldObj->createRole("il_grp_admin_".$this->getRefId(),"Groupadmin of group obj_no.".$this->getId());
                $this->m_roleAdminId = $roleObj->getId();

                //set permission template of new local role
                $q = "SELECT obj_id FROM object_data WHERE type='rolt' AND title='il_grp_admin'";
                $r = $this->ilias->db->getRow($q, DB_FETCHMODE_OBJECT);
                $rbacadmin->copyRolePermission($r->obj_id,ROLE_FOLDER_ID,$rfoldObj->getRefId(),$roleObj->getId());

                // set object permissions of group object
                $ops = $rbacreview->getOperationsOfRole($roleObj->getId(),"grp",$rfoldObj->getRefId());
                $rbacadmin->grantPermission($roleObj->getId(),$ops,$this->getRefId());

                // set object permissions of role folder object
                $ops = $rbacreview->getOperationsOfRole($roleObj->getId(),"rolf",$rfoldObj->getRefId());
                $rbacadmin->grantPermission($roleObj->getId(),$ops,$rfoldObj->getRefId());

                // MEMBER ROLE
                // create role and assign role to rolefolder...
                $roleObj = $rfoldObj->createRole("il_grp_member_".$this->getRefId(),"Groupmember of group obj_no.".$this->getId());
                $this->m_roleMemberId = $roleObj->getId();

                //set permission template of new local role
                $q = "SELECT obj_id FROM object_data WHERE type='rolt' AND title='il_grp_member'";
                $r = $this->ilias->db->getRow($q, DB_FETCHMODE_OBJECT);
                $rbacadmin->copyRolePermission($r->obj_id,ROLE_FOLDER_ID,$rfoldObj->getRefId(),$roleObj->getId());
                
                // set object permissions of group object
                $ops = $rbacreview->getOperationsOfRole($roleObj->getId(),"grp",$rfoldObj->getRefId());
                $rbacadmin->grantPermission($roleObj->getId(),$ops,$this->getRefId());

                // set object permissions of role folder object
                $ops = $rbacreview->getOperationsOfRole($roleObj->getId(),"rolf",$rfoldObj->getRefId());
                $rbacadmin->grantPermission($roleObj->getId(),$ops,$rfoldObj->getRefId());

                unset($rfoldObj);
                unset($roleObj);

                $roles[] = $this->m_roleAdminId;
                $roles[] = $this->m_roleMemberId;
                return $roles ? $roles : array();
        }

        function notify($a_event,$a_ref_id,$a_parent_non_rbac_id,$a_node_id,$a_params = 0)
        {
                global $tree;
                
                $parent_id = (int) $tree->getParentId($a_node_id);
                
                if ($parent_id != 0)
                {
                        $obj_data =& $this->ilias->obj_factory->getInstanceByRefId($a_node_id);
                        $obj_data->notify($a_event,$a_ref_id,$a_parent_non_rbac_id,$parent_id,$a_params);
                }
                                
                return true;
        }

        function _search(&$a_search_obj)
        {
                global $ilBench;

                // NO CLASS VARIABLES IN STATIC METHODS

                $where_condition = $a_search_obj->getWhereCondition("like",array("title","description"));
                $in = $a_search_obj->getInStatement("ore.ref_id");

                $query = "SELECT ore.ref_id AS ref_id FROM object_data AS od, object_reference AS ore ".
                        $where_condition." ".
                        $in." ".
                        "AND od.obj_id = ore.obj_id ".
                        "AND od.type = 'grp' ";

                $ilBench->start("Search", "ilObjGroup_search");
                $res = $a_search_obj->ilias->db->query($query);
                $ilBench->stop("Search", "ilObjGroup_search");

                $counter = 0;

                while ($row = $res->fetchRow(DB_FETCHMODE_OBJECT))
                {
                        $result_data[$counter++]["id"]                          =  $row->ref_id;
                        #$result_data[$counter]["link"]                         =  "group.php?cmd=view&ref_id=".$row->ref_id;
                        #$result_data[$counter++]["target"]                     =  "";
                }

                return $result_data ? $result_data : array();
        }

        function _getLinkToObject($a_id)
        {
                return array("repository.php?ref_id=".$a_id."&set_mode=flat&cmdClass=ilobjgroupgui","");
        }
        
        function isUserRegistered($a_user_id = 0)
        {
                global $rbacsystem;
                
                // exclude system role from check
                if (in_array(SYSTEM_ROLE_ID,$_SESSION["RoleId"]))
                {
                        return true;            
                }

                if (!$this->isMember() or !$rbacsystem->checkAccess("join", $this->ref_id))
                {
                        return false;
                }
                
                return true;
        }
} //END class.ilObjGroup
?>