if ( jQuery.support.html5Clone || jQuery.isXMLDoc(elem) || !rnoshimcache.test( "<" + elem.nodeName + ">" ) ) {clone = elem.cloneNode( true );// IE<=8 不能正确克隆已分离、未知的节点
//直接新建一个相同的节点，然后获取
} else {　　//fragmentDiv是全局变量fragmentDiv.innerHTML = elem.outerHTML;fragmentDiv.removeChild( clone = fragmentDiv.firstChild );
}

//针对ie克隆问题修正
if ( (!jQuery.support.noCloneEvent || !jQuery.support.noCloneChecked) &&(elem.nodeType === 1 || elem.nodeType === 11) && !jQuery.isXMLDoc(elem) ) {//在这里我们不使用Sizzle的原因是: http://jsperf.com/getall-vs-sizzle/2destElements = getAll( clone );srcElements = getAll( elem );//修正所有IE克隆问题for ( i = 0; (node = srcElements[i]) != null; ++i ) {// Ensure that the destination node is not null; Fixes #9587if ( destElements[i] ) {fixCloneNodeIssues( node, destElements[i] );}}
}

//克隆绑定的事件
if ( dataAndEvents ) {if ( deepDataAndEvents ) {srcElements = srcElements || getAll( elem );destElements = destElements || getAll( clone );for ( i = 0; (node = srcElements[i]) != null; i++ ) {cloneCopyEvent( node, destElements[i] );}} else {cloneCopyEvent( elem, clone );}
}

    function cloneCopyEvent( src, dest ) {if ( dest.nodeType !== 1 || !jQuery.hasData( src ) ) {return;}var type, i, l,oldData = jQuery._data( src ),curData = jQuery._data( dest, oldData ),//dest是克隆对的节点events = oldData.events;if ( events ) {//保证被克隆的节点的事件对象干净，确保没有后面添加的事件没有重复delete curData.handle;curData.events = {};for ( type in events ) {for ( i = 0, l = events[ type ].length; i < l; i++ ) {jQuery.event.add( dest, type, events[ type ][ i ] );}}}// 使克隆的数据对象化if ( curData.data ) {curData.data = jQuery.extend( {}, curData.data );}}

View Code

destElements = getAll( clone, "script" );
if ( destElements.length > 0 ) {setGlobalEval( destElements, !inPage && getAll( elem, "script" ) );
}destElements = srcElements = node = null;return clone;

    // IE6-8当使用cloneNode复制事件（这些事件绑定通过attachEvent）时进入该分支//清除原来的事件，为克隆事件做准备if ( !jQuery.support.noCloneEvent && dest[ jQuery.expando ] ) {data = jQuery._data( dest );for ( e in data.events ) {jQuery.removeEvent( dest, e, data.handle );}dest.removeAttribute( jQuery.expando );}

    //IE克隆脚本时内容为空白，并试图执行新设置的文本if ( nodeName === "script" && dest.text !== src.text ) {disableScript( dest ).text = src.text;restoreScript( dest );}

    //IE6-10不能克隆使用的classid获取的对象元素的子节点。//IE10下，如果父节点为null,则会抛出NoModificationAllowedError异常else if ( nodeName === "object" ) {if ( dest.parentNode ) {dest.outerHTML = src.outerHTML;}//对于IE9,这个条分支不可避免。//IE9中克隆对象元素，上述outerHTML策略是不充分的。//如果src具有的innerHTML并且克隆节点却没有，//复制src.innerHTML到dest.innerHTML #10324if ( jQuery.support.html5Clone && ( src.innerHTML && !jQuery.trim(dest.innerHTML) ) ) {dest.innerHTML = src.innerHTML;}}

    // manipulation_rcheckableType = /^(?:checkbox|radio)$/ielse if ( nodeName === "input" && manipulation_rcheckableType.test( src.type ) ) {//IE6-8无法坚持一个克隆的复选框或单选按钮的选中状态//更糟的是，如果defaultChecked值没有设置，则IE6-7无法给克隆元素选中状态的外观dest.defaultChecked = dest.checked = src.checked;...}

　　　//当克隆选项时，IE6-8无法正确返回select默认选中状态else if ( nodeName === "option" ) {dest.defaultSelected = dest.selected = src.defaultSelected;}

    //当克隆其他类型的input标签时，IE6-8不能正确设置defaultValue为正确的值else if ( nodeName === "input" || nodeName === "textarea" ) {dest.defaultValue = src.defaultValue;}

//为安全DOM操作替换/保存script节点元素type属性
function disableScript( elem ) {var attr = elem.getAttributeNode("type");elem.type = ( attr && attr.specified ) + "/" + elem.type;return elem;
}