设计模式之发布/订阅模式

来源：互联网发布：内衣淘宝代销编辑：程序博客网时间：2024/05/29 15:05
<pre name="code" class="html"><html>  <head>    <title>Observer</title>    <script type="text/javascript" src="js/jquery-1.12.4.min.js"></script>  </head>  <body>    <script type="text/javascript">      var pubsub = (function() {        //订阅者列表        var events = {};        var subUid = 0;        //发布        function publish(eventName, args) {          if (!events[eventName]) {            return false;          }          var subscribers = events[eventName];          var len = subscribers.length;          while (len--) {            subscribers[len].callback(eventName, args);          }        }        //订阅        function subscribe(eventName, callback) {          events[eventName] = events[eventName] || [];          var id = subUid++;          events[eventName].push({            callback: callback,            id: id          });          return id;        }        //取消订阅        function unsubscribe(id) {          var eventName;          var i;          var len;          var subscribers;          for (eventName in events) {            subscribers = events[eventName];            if (subscribers) {              for (i = 0, len = subscribers.length; i < len; i++) {                if (subscribers[i].id === id) {                  subscribers.splice(i, 1);                  return id;                }              }            }          }          return this;        }        //利用Revealing Module模式隐藏内部实现，提供接口        return {          publish: publish,          subscribe: subscribe,          unsubscribe: unsubscribe        };      }());      //在hello事件生增加一个订阅      var subscription = pubsub.subscribe("hello", function(eventName, data) {        console.log("Event:" + eventName + "/data:" + data);      });      //向订阅者发送消息      pubsub.publish("hello", ["天镶"]);      //向订阅者发送消息      pubsub.publish("hello", ["天镶", "求", "offer"]);      //取消订阅      pubsub.unsubscribe(subscription);      //向订阅者发送消息      pubsub.publish("hello", ["天镶", "再求", "offer"]);    </script>  </body></html>
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