PhutilEventListener.php
3d64a0a95fc5stable

PhutilEventListener.php
View Options

			<?php

			/*
			* Copyright 2012 Facebook, Inc.
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			/**
			* @group event
			* @stable
			*/
			abstract class PhutilEventListener {

			private $listenerID;
			private static $nextListenerID = 1;

			final public function __construct() {
			// <empty>
			}

			abstract public function register();
			abstract public function handleEvent(PhutilEvent $event);

			final public function listen($type) {
			$engine = PhutilEventEngine::getInstance();
			$engine->addListener($this, $type);
			}


			/**
			* Return a scalar ID unique to this listener. This is used to deduplicate
			* listeners which match events on multiple rules, so they are invoked only
			* once.
			*
			* @return int A scalar unique to this object instance.
			*/
			final public function getListenerID() {
			if (!$this->listenerID) {
			$this->listenerID = self::$nextListenerID;
			self::$nextListenerID++;
			}
			return $this->listenerID;
			}


			}