js自定义事件

自定义事件的本质，创建一个对象，然后把事件的名字作为对象的一个属性，然后value是一个[],把此事件的所以回调都push进去。

写一个很基本的，没有把对象暴露出去的js的自定义事件。

var event = (function(){
  var obj = {};
  var addEvent = function(type,cb){
    if(!obj[type]){
        obj[type] = [];
    }
    return obj[type].push(cb);
  }
  var removeEvent = function(type){
    return obj[type] = null;
  }
  var fireEvent = function(type){
    for(var i = 0;i<obj[type].length;i++){
      obj[type][i]();
    }
  }
  return {
    add:addEvent,
    remove:removeEvent,
    fire:fireEvent
  }
})();
var on = function(type,param){
  if(typeof param == "function"){
    event.add(type,param);
  }else{
    event.fire(type);
  }
}
var off = function(type){
  event().remove(type);
}
on("hello",function(){console.log("你好世界");});
on("hello",function(){console.log("我是飘飘然");});
on("hello");

这里我们提供一个可以放入sdk中的

 customEvent = (function() {
      var S4, addCustomEvent, cgid, fireCustomEvent, guid, listeners, removeCustomEvent;
      S4 = function() {
        return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
      };
      guid = function() {
        return S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4();
      };
      listeners = {};
      cgid = '__ceGUID';//cgid = guid; 目的为了防止框架定义的obj属性和用户定义属性的相同
      addCustomEvent = function(obj, event, callback) {
        obj[cgid] = undefined;
        if (!obj[cgid]) {
          obj[cgid] = "ifvisible.object.event.identifier";
        }
        if (!listeners[obj[cgid]]) {
          listeners[obj[cgid]] = {};
        }
        if (!listeners[obj[cgid]][event]) {
          listeners[obj[cgid]][event] = [];
        }
        return listeners[obj[cgid]][event].push(callback);
      };
      fireCustomEvent = function(obj, event, memo) {
        var ev, j, len, ref, results;
        if (obj[cgid] && listeners[obj[cgid]] && listeners[obj[cgid]][event]) {
          ref = listeners[obj[cgid]][event];
          results = [];
          for (j = 0, len = ref.length; j < len; j++) {
            ev = ref[j];
            results.push(ev(memo || {}));
          }
          return results;
        }
      };
      removeCustomEvent = function(obj, event, callback) {
        var cl, i, j, len, ref;
        if (callback) {
          if (obj[cgid] && listeners[obj[cgid]] && listeners[obj[cgid]][event]) {
            ref = listeners[obj[cgid]][event];
            for (i = j = 0, len = ref.length; j < len; i = ++j) {
              cl = ref[i];
              if (cl === callback) {
                listeners[obj[cgid]][event].splice(i, 1);
                return cl;
              }
            }
          }
        } else {
          if (obj[cgid] && listeners[obj[cgid]] && listeners[obj[cgid]][event]) {
            return delete listeners[obj[cgid]][event];
          }
        }
      };
      return {
        add: addCustomEvent,
        remove: removeCustomEvent,
        fire: fireCustomEvent
      };
    })();