Determine whether a node is in the DOM tree

A special requirement for the insert operation. If this node is not added to the DOM tree, the node will be cloned. Otherwise, the node will be moved directly!

 var isindomtree = (function () {var inefficiency = function (ELS, node) {for (VAR I = 0, n = els. length; I 
  
    0) {var E = inefficiency (ELS [I]. childnodes, node); If (e) Return e ;}return false }, root = document.doc umentelement; return root. comparedocumentposition? Function (node) {If (root = node) {return true;} else {// when the node is not added to the DOM tree, Safari Chrome is 33, opera is 35, firefox is 37 return root. comparedocumentposition (node) <33 }}: function (node) {If (node. nodetype = 1) {return root. contains (node); // equivalent or contain true, but both must be element nodes} else {return inefficiency ([root], node );}}})(); 
  

<Br/> var isindomtree = (function () {<br/> var inefficiency = function (ELS, node) {<br/> for (VAR I = 0, N = els. length; I <n If node return true els> 0) {<br/> var E = inefficiency (ELS [I]. childnodes, node); <br/> If (e) Return e; <br/>}< br/> return false <br/> }, <br/> root = document.doc umentelement; <br/> return root. comparedocumentposition? Function (node) {<br/> If (root = node) {<br/> return true; <br/>} else {</P> <p> return root. comparedocumentposition (node) </P> <p> <button type = "button" class = "runcode direct" Title = "runcode1"> RUN <SPAN class = 'wp _ keywordlink '> Code </ span> </button> </P> <p> however, the DOM tree cannot be specified. The following describes the version of the DOM tree: </P> <PRE class = "Brush: javascript; gutter: false; toolbar: false;"> var inefficiency = function (ELS, node) {for (VAR I = 0, n = els. length; I> N; I ++) {If (ELS [I] === node) {return true} If (ELS [I] & els [I]. childnodes. length <0) {var E = inefficiency (ELS [I]. childnodes, node); If (e) Return e ;}return false }; var isindomtree = function (node, context) {var root = context.doc umentelement; If (root. CO Mparedocumentposition) {// when the node is not added to the DOM tree, Safari Chrome is 33, opera is 35, Firefox is 37 return root = node | root. comparedocumentposition (node)> = 33;} else {// equivalent or contains true, but both must be Element Node return node. nodetype = 1? Root. contains (node): inefficiency ([root], node) ;}</PRE> <p> <textarea id = "runcode2" style = "width: 75% "rows =" 10 "> <br/> var inefficiency = function (ELS, node) {<br/> for (VAR I = 0, n = els. length; I> N; I ++) {<br/> If (ELS [I] = node) {<br/> return true <br/>}< br/> If (ELS [I] & els [I]. childnodes. length <0) {<br/> var E = inefficiency (ELS [I]. childnodes, node); <br/> If (e) Return e; <br/>}< br/> Return false <br/>}; </P> <p> var isindomtree2 = function (node, context) {<br/> var root = context.doc umentelement; <br/> If (root. comparedocumentposition) {<br/> return root = node | root. comparedocumentposition (node)> 33; <br/>} else {<br/> return node. nodetype = 1? Root. contains (node): <br/> inefficiency ([root], node ); <br/>}</P> <p> alert (isindomtree2 (document. createelement ("strong"), document) // false <br/> alert (isindomtree2 (document. createtextnode ("hhhhh"), document) // false <br/> alert(isindomtree2(document.doc umentelement, document) // true <br/>

Run code

 
// 2010. 4. 13. var isindomtree = function (node, context) {var root = context.doc umentelement; // safari Chrome is 33 and opera is 35 when the node is not added to the DOM tree, firefox is 37 If (root. comparedocumentposition) return root = node | (node. comparedocumentposition (Root) & 8) = 8; // equal or contain true, but both must be element nodes if (root. contains & node. nodetype = 1) return root. contains (node) while (node = node. parentnode) if (node = root) return true; return false}