javascript事件之：jQuery事件中实例对象和拓展对象之间的通信

　　我们总结过jQery事件中的实例原型对象对外接口和拓展对象，现在我们看看他们是如何进行通信联系的。

先来看便捷方法：

//调用的还是实例对象下的on()和trigger()
jQuery.each( ("blur focus focusin focusout load resize scroll unload click dblclick " +
    "mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave " +
    "change select submit keydown keypress keyup error contextmenu").split(" "), function( i, name ) {
    jQuery.fn[ name ] = function( data, fn ) {
        return arguments.length > 0 ?
            this.on( name, null, data, fn ) :
            this.trigger( name );
    };
});

jQuery.fn.extend({
    //调用的是上面实例的mouseenter和mouseleave
    hover: function( fnOver, fnOut ) {
        return this.mouseenter( fnOver ).mouseleave( fnOut || fnOver );
    },
    //调用的是实例下的on
    bind: function( types, data, fn ) {
        return this.on( types, null, data, fn );
    },
    //调用的是实例下的off
    unbind: function( types, fn ) {
        return this.off( types, null, fn );
    },
    //调用的是实例下的on
    delegate: function( selector, types, data, fn ) {
        return this.on( types, selector, data, fn );
    },
    //调用的是实例下的off
    undelegate: function( selector, types, fn ) {
        // ( namespace ) or ( selector, types [, fn] )
        return arguments.length === 1 ? this.off( selector, "**" ) : this.off( types, selector || "**", fn );
    }
});

所以便捷方法知识调用了实例下的on，off，triger三个方法。其本身的学习价值不高。

接下来是另外几个供便捷方法调用的实例方法。

jQuery.fn.extend({
    //调用的是jQuery.event下的add()
    on: function( types, selector, data, fn, /*INTERNAL*/ one ) { 
        jQuery.event.add( this, types, fn, data, selector );...
    },
    //调用的是上面的on
    one: function( types, selector, data, fn ) {
        return this.on( types, selector, data, fn, 1 );
    },
    //调用的是jQuery.event下的remove()
    off: function( types, selector, fn ) {
        jQuery.event.remove( this, types, fn, selector );...
    },
    //调用的是jQuery.event下的trigger()
    trigger: function( type, data ) {
        return this.each(function() {
            jQuery.event.trigger( type, data, this );
        });
    },
    //调用的是jQuery.event下的trigger()
    triggerHandler: function( type, data ) {
        return jQuery.event.trigger( type, data, elem, true );...
    }
})    

这里调用的主要是jQuery.event下的3个方法：add(), remove(), trigger()。其本身的学习意义也不大。我们来看jQuery.event下的这三个方法。

jQuery.event = {
    global: {},
    //绑定事件
    add: function( elem, types, handler, data, selector ) {
        ...
        special = jQuery.event.special[ type ] || {};
        ...
        jQuery.event.dispatch.apply( eventHandle.elem, arguments )
        
    },
    //移除事件
    remove: function( elem, types, handler, selector, mappedTypes ) {
        ...
        special = jQuery.event.special[ type ] || {};
        if ( rfocusMorph.test( type + jQuery.event.triggered ) ) {
    },
    //手动触发事件
    trigger: function( event, data, elem, onlyHandlers ) {}，
    //事件分发
    dispatch: function( event ) {},
    handlers: function( event, handlers ) {},
    props: "altKey bubbles cancelable ctrlKey currentTarget eventPhase metaKey relatedTarget shiftKey target timeStamp view which".split(" "),
    fixHooks: {},
    //对键盘事件对象的属性和修正方法
    keyHooks: {},
    //对鼠标事件对象的属性和修正方法
    mouseHooks: {},
    //兼容性相关
    fix: function( event ) {},
    //事件修正对象集
    special: {
        load: {
            noBubble: true
        }，
        focus: {
            trigger: function() {},
            delegateType: "focusin"
        },
        blur: {
            trigger: function() {},
            delegateType: "focusout"
        },
        click: {
            trigger: function() {},
            _default: function(){}
        },
        beforeunload: {
            postDispatch: function( event ) {}
        }
    },
    //模拟事件，修正事件兼容性游泳
    simulate: function( type, elem, event, bubble ) {}
}

jQuery事件对象下的这三个方法是主题。其余都是修正浏览器的兼容性和为这三个方法服务的工具方法。