js事件模型与自定义事件实例解析

var eventModel = { list: {}, bind: function () { var args = [].slice.call(arguments), type = args[0], handlers = args.slice(1); if (typeof type === 'string' && handlers.length > 0) {  for (var i = 0; i < handlers.length; i++) {  if (typeof handlers[i] === 'function') {   if (!this.list[type]) {   this.list[type] = [];   }   this.list[type].push(handlers[i]);  }  } } }, unbind: function () { var type = arguments[0], handlers = Array.prototype.slice.call(arguments, 1); if (typeof type === 'string') {  if (handlers.length === 0) {  this.list[type] = [];  } else {  for (var i = 0; i < handlers.length; i++) {   if (typeof handlers[i] === 'function' && handlers[i] === this.list[type][i]) {   this.list[type].splice(i, 1);   }  }  } } }, trigger: function () { var arguments = [].slice.call(arguments), type = arguments[0], args = arguments[1] instanceof Array && !arguments[2] ? arguments[1] : arguments.slice(1), handlers = this.list[type]; for (var i = 0; i < handlers.length; i++) {  handlers[i].apply(this, args.splice(0, handlers[i].length)); } }};

eventModel.bind('myevent1', function (a) { console.log(a); // 1}, function(b) { console.log(b); // 2}, function(c, d) { console.log(c + ' + ' + d); // a + b});eventModel.bind('myevent1', function (e) { console.log(e); // 50});eventModel.trigger('myevent1', 1,2,'a','b', 50);

<button id="bind">bind</button><button id="unbind">unbind</button>

var fnX = function () { console.log('fnX');}var fnY = function () { console.log('fnY');}eventModel.bind('myevent2', fnX, fnY);document.getElementById('unbind').onclick = function () { eventModel.unbind('myevent2', fnX); //删除 fnX 后，只剩下 fnY};document.getElementById('bind').onclick = function () { eventModel.trigger('myevent2'); //输出 fnX fnY //在点击unbind后，只输出 fnY};