Gpf_Rpc_Action::setErrorMessage PHP Method

        public function setErrorMessage($message)
        {
            $this->errorMessage = $message;
        }

    /**
     * @service channel write
     *
     * @param $fields
     * @return Gpf_Rpc_Action
     */
    public function saveFields(Gpf_Rpc_Params $params) {
        $action = new Gpf_Rpc_Action($params);
        $action->setErrorMessage($this->_('Failed to save %s field(s)'));
        $action->setInfoMessage($this->_('%s field(s) successfully saved'));
        
        $fields = new Gpf_Data_RecordSet();
        $fields->loadFromArray($action->getParam("fields"));
        
        $channels = Pap_Db_Table_Channels::getUserChannels(Gpf_Session::getAuthUser()->getPapUserId());
        
        foreach ($fields as $field) {
        	$isUnique = true;
        	foreach ($channels as $channel) {
        		if ($field->get('value') == $channel->get(Pap_Db_Table_Channels::VALUE)) {
        			$isUnique = false;
        			break;
        		}
        	}
        	if ($isUnique) {
        		$this->saveField($field);
        	} else {
        		$action->setErrorMessage($this->_("Failed to save %s field(s). Data with value '".$field->get('value').
        		  "' already exist. Data must be unique."));
        		$action->addError();
        		return $action;
        	}
        }

        $action->addOk();

        return $action;
    }