modUser Join Group

$this->xpdo->log(xPDO::LOG_LEVEL_ERROR,'Role not found with key: '.$role);

$this->xpdo->log(xPDO::LOG_LEVEL_ERROR,'Role not found with key: '.$roleId);

/**
 * Join a User Group, and optionally assign a Role.
 * (This method is borrowed from MODX moduser.class.php and 
 * modified, as the original method has some bugs in 2.3.1.
 * All references to xpdo are replaced with modx.)
 *
 * @access public
 * @param mixed $groupId Either the name or ID of the User Group to join.
 * @param mixed $roleId Optional. Either the name or ID of the Role to assign to for the group.
 * @param modUser $user The user object (Needed because $this is not a modUser object as in moduser.class.php)
 * @return boolean True if successful.
 */
public function joinGroup($groupId, $roleId = null, $user) {
    $joined = false;

    $groupPk = is_string($groupId) ? array('name' => $groupId) : $groupId;
    /** @var modUserGroup $userGroup */
    $userGroup = $this->modx->getObject('modUserGroup', $groupPk);
    if (empty($userGroup)) {
        $this->modx->log(modX::LOG_LEVEL_ERROR, 'User Group not found with key: '.$groupId);
        return $joined;
    }

    /** @var modUserGroupRole $role */
    if (!empty($roleId)) {
        $rolePk = is_string($roleId) ? array('name' => $roleId) : $roleId;
        $role = $this->modx->getObject('modUserGroupRole', $rolePk);
        if (empty($role)) {
            //$this->xpod->log(xPDO::LOG_LEVEL_ERROR,'Role not found with key: '.$role);
            $this->modx->log(modX::LOG_LEVEL_ERROR, 'Role not found with key: '.$roleId); // bugfix
            return $joined;
        }
    }

    /** @var modUserGroupMember $member */
    $member = $this->modx->getObject('modUserGroupMember', array(
        //'member' => $this->get('id'), // Original line from moduser.class.php
        'member' => $user->get('id'),   // Needed because $this is not a modUser object as in moduser.class.php
        'user_group' => $userGroup->get('id'),
    ));
    if (empty($member)) {
        $rank = count($user->getMany('UserGroupMembers'));
        $member = $this->modx->newObject('modUserGroupMember');
        //$member->set('member', $this->get('id')); // Original line from moduser.class.php
        $member->set('member', $user->get('id'));   // Needed because $this is not a modUser object as in moduser.class.php
        $member->set('user_group', $userGroup->get('id'));
        $member->set('rank', $rank);
        if (!empty($role)) {
            $member->set('role', $role->get('id'));
        }
        // -- additional code: allow joining User Groups without assigning a role
        if ($roleId === '0' || $roleId === 0) { 
            $member->set('role', 0);
        }
        // -- end: additional code
        $joined = $member->save();
        if (!$joined) {
            $this->modx->log(modX::LOG_LEVEL_ERROR, 'An unknown error occurred preventing adding the User to the User Group.');
        } else {
            //unset($_SESSION["modx.user.{$this->get('id')}.userGroupNames"]); // Original line from moduser.class.php
            unset($_SESSION["modx.user.{$user->get('id')}.userGroupNames"]);   // Needed because $this is not a modUser object as in moduser.class.php
        }
    } else {
        $joined = true;
    }
    return $joined;
}