JavaScript The simplest event model requires event binding and triggering, as well as event deletion.
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)); } } };
It mainly implements bind (binding event), unbind (deletion event) and trigger (trigger event). For the same event name, multiple event processing functions can be bound; they will be triggered sequentially in the order of binding.
args.splice(0, handlers[i].length) Parameters passed when triggered
Event binding and triggering:
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);
Event deletion:
<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 };
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