javascript事件之：jQuery.event.remove事件详解

　　之前已经介绍过jQuery.event.add，现在我们来看看jQuery.event.remove

　　先上代码

/*
    elem: 处理的元素
    types: 移除的事件
    handler: 移除的方法
    selector: 委托的元素
    mappedTypes:
*/
remove: function( elem, types, handler, selector, mappedTypes ) {
    var j, origCount, tmp,
        events, t, handleObj,
        special, handlers, type, namespaces, origType,
        //得到绑定在elem上的data缓存
        elemData = data_priv.hasData( elem ) && data_priv.get( elem );
    // 没有elemData或者elemData.events，退出函数
    if ( !elemData || !(events = elemData.events) ) {
        return;
    }
    // 处理用空格分割开的多事件操作
    types = ( types || "" ).match( core_rnotwhite ) || [""];
    t = types.length;
    while ( t-- ) {
        //typenamespace = /^([^.]*)(?:\.(.+)|)$/;
        tmp = rtypenamespace.exec( types[t] ) || [];
        type = origType = tmp[1];
        namespaces = ( tmp[2] || "" ).split( "." ).sort();

        // 移除该元素下所有事件
        if ( !type ) {
            for ( type in events ) {
                jQuery.event.remove( elem, type + types[ t ], handler, selector, true );
            }
            continue;
        }

        special = jQuery.event.special[ type ] || {};
        type = ( selector ? special.delegateType : special.bindType ) || type;
        handlers = events[ type ] || [];
        //如果存在命名空间，得到一个带命名空间的正则
        tmp = tmp[2] && new RegExp( "(^|\\.)" + namespaces.join("\\.(?:.*\\.|)") + "(\\.|$)" );
        origCount = j = handlers.length;
        while ( j-- ) {
            //得到handlers下的一个handleObj
            handleObj = handlers[ j ];
            if ( ( mappedTypes || origType === handleObj.origType ) &&
                ( !handler || handler.guid === handleObj.guid ) &&
                ( !tmp || tmp.test( handleObj.namespace ) ) &&
                ( !selector || selector === handleObj.selector || selector === "**" && handleObj.selector ) ) {
                // 移除handlers下对应的事件对象
                handlers.splice( j, 1 );
                // 处理delegateCount
                if ( handleObj.selector ) {
                    handlers.delegateCount--;
                }
                // 如果specia下有remove，调用
                if ( special.remove ) {
                    special.remove.call( elem, handleObj );
                }
            }
        }

        // Remove generic event handler if we removed something and no more handlers exist
        // (avoids potential for endless recursion during removal of special event handlers)
        if ( origCount && !handlers.length ) {
            if ( !special.teardown || special.teardown.call( elem, namespaces, elemData.handle ) === false ) {
                jQuery.removeEvent( elem, type, elemData.handle );
            }
            // 移除evens下类型
            delete events[ type ];
        }
    }

    // Remove the expando if it‘s no longer used
    if ( jQuery.isEmptyObject( events ) ) {
        delete elemData.handle;
        data_priv.remove( elem, "events" );
    }
},