1 function msgBus(){ 2  3     var msgMap = {}; // internal message bus 4     var instance = {}; 5  6  7     /** 8      * @function subscribe 9      * @description subscribe message listener.10      * @param msgType {string} - message type to be listen.11      * @param handler {function} - handler function when the message sent.12      * @instance13      */14     instance.subscribe = function(msgType,handler){15         if(msgType == null){16             console.error("Message type is null");17             return instance;18         }19         if(handler == null){20             console.error("handler is null");21             return instance;22         }23         var subscribeArray = msgMap[msgType];24         if(subscribeArray == null){25             subscribeArray = new Array();26             msgMap[msgType] = subscribeArray;27         }28         if(subscribeArray.indexOf(handler) < 0){29             subscribeArray.push(handler);30         }31         return instance;32     }33 34     /**35      * @function unsubscribe36      * @description unsubscribe message listener.37      * @param msgType {string} - message type to be unsubscribe.38      * @param handler {function} - handler function to be removed.39      * @instance40      */41 42     instance.unsubscribe = function(msgType,handler){43         var subscribeArray = msgMap[msgType];44         if(subscribeArray != null){45             var index = subscribeArray.indexOf(handler);46             if(index > 0){47                 subscribeArray.splice(index,1);48             }49         }50 51         return instance;52     }53 54 55     /**56      * @function publish57      * @description publish message.58      * @param msgType {string} - message type to be published.59      * @param data {object} - message data.60      * @instance61      */62     instance.publish = function(msgType,data){63         var subscribeArray = msgMap[msgType];64         if(subscribeArray == null){65             return;66         }67         for(var i=0;i<subscribeArray.length;i++){68             try{69                 subscribeArray[i](data);70             }catch(e){71                 console.error("Error when sending Message: "+msgType);72             }73         }74 75         return instance;76     }77 78     return instance;79 }

var instance = msgBus();instance.subscribe("subscribe",function(data){console.log("this is "+data)});instance.publish("subscribe","cangjingkong"); // this is cangjingkong