Javascript模块模式事件和监听器

Question

我正在实现模块模式,并想知道定义和注册事件监听器/处理程序的最佳/首选方式.以下工作,但也许有更好/更简单的方式......

var  MODULE = function() {

    //  private
    var _field1;
    var _field2;

    function  localFunc(p) {
        alert('localFunc');
    }

    //  public
    return {
        // properties
        prop1: _field1,

        // events
        myEvent1Handler: {},
        myEvent1: function() {myEvent1Handler();},
        myEvent2Handler: {},
        myEvent2: function() {myEvent2Handler();},

        addListener: function  (event,func) {
            if (event  ==  "myEvent1")
                myEvent1Handler = func;   

            if (event  ==  "myEvent2")
                myEvent2Handler = func;      
        },

        // public  methods
        method1: function (p) {
            alert('method1 says:' + p);
            MODULE.myEvent1();
        },
        method2: function  (p) {
             alert('method2 doing  stuff');
             localFunc(p);
            MODULE.myEvent2();
        }

    };
}();

// register for events
MODULE.addListener("myEvent1",function(){alert('fired1');});  
MODULE.addListener("myEvent2",function(){alert('fired2');});  

// use module (only event1 should fire!)
MODULE.method1("hello");  

试试看:

http://jsfiddle.net/RqusH/3/

看起来像myEventx,myEventHandlerx和addListener有很多工作要做？

Answer 1

通常,我不会回应具有特定实现的架构问题(尤其是依赖于第三方库(如jQuery)的架构问题),但由于我的实现提升了可重用性 - 我们在这里讨论模式 - 我将提供一个小的jQuery插件,$ .eventable,它使用jQuery的事件方法扩充JavaScript对象.

这个插件允许您通过一个简单的调用在任何对象(或类实例)上实现事件处理功能.

jQuery.eventable = function (obj) {
  // Allow use of Function.prototype for shorthanding the augmentation of classes
  obj = jQuery.isFunction(obj) ? obj.prototype : obj;
  // Augment the object (or prototype) with eventable methods
  return $.extend(obj, jQuery.eventable.prototype);
};

jQuery.eventable.prototype = {

  // The trigger event must be augmented separately because it requires a
  // new Event to prevent unexpected triggering of a method (and possibly
  // infinite recursion) when the event type matches the method name
  trigger: function (type, data) {
    var event = new jQuery.Event(type); 
    event.preventDefault();                
    jQuery.event.trigger(event, data, this);
    return this;
  }
};

// Augment the object with jQuery's event methods
jQuery.each(['bind', 'one', 'unbind', 'on', 'off'], function (i, method) {
  jQuery.eventable.prototype[method] = function (type, data, fn) {
    jQuery(this)[method](type, data, fn);
    return this;
  };
});

如果您包含该代码段,则可以像这样实现您的解决方案:

var MODULE = function() {

  //  private
  var _field1;
  var _field2;

  function localFunc(p) {
    alert('localFunc');
  }

  //  public
  return $.eventable({

    // properties
    prop1: _field1,

    // public  methods
    method1: function(p) {
      alert('method1 says:' + p);
      this.trigger('myEvent1');
    },

    method2: function(p) {
      alert('method2 doing  stuff');
      localFunc(p);
      this.trigger('myEvent2');
    }

  });
} ();

// register for events
MODULE.on("myEvent1", function() {
  alert('fired1');
});
MODULE.on("myEvent2", function() {
  alert('fired2');
});

// use module (only event1 should fire!)
MODULE.method1("hello");

您的MODULE现在具有以下可调用方法:

MODULE.on(event, /* data, */ handler);
MODULE.bind(event, /* data, */ handler);
MODULE.one(event, /* data ,*/ handler);
MODULE.off(event, handler);
MODULE.unbind(event, handler);
MODULE.trigger(event /*, data */);

where事件是以空格分隔的事件列表,handler是您的回调,data是传递给回调的可选值.

您可以参考jQuery的文档以获取更多详细信息.