getElementsByClassName

摘要: getElementsByClassName

var getElementsByClassName = function (className, tag, elm){
　　if (document.getElementsByClassName) {
　　getElementsByClassName = function (className, tag, elm) {
　　elm = elm || document;
　　var elements = elm.getElementsByClassName(className),
　　nodeName = (tag)? new RegExp("\\b" + tag + "\\b", "i") : null,
　　returnElements = [],　current;
　　for(var i=0, il=elements.length; i
　　current = elements[i];
　　if(!nodeName || nodeName.test(current.nodeName)) {
　　returnElements.push(current);}}
　　return returnElements;};}
　　else if (document.evaluate) {getElementsByClassName = function (className, tag, elm) {
　　tag = tag || "*";elm = elm || document;var classes = className.split(" "),classesToCheck = "",
　　xhtmlNamespace = "http://www.w3.org/1999/xhtml",
　　namespaceResolver = (document.documentElement.namespaceURI === xhtmlNamespace)? xhtmlNamespace : null,
　　returnElements = [],elements,node;
　　for(var j=0, jl=classes.length; j
　　classesToCheck += "[contains(concat( , @class , ), " + classes[j] + " )]";
　　}try {elements = document.evaluate(".//" + tag + classesToCheck, elm, namespaceResolver, 0, null);
　　}catch (e) {elements = document.evaluate(".//" + tag + classesToCheck, elm, null, 0, null);}
　　while ((node = elements.iterateNext())) {
　　returnElements.push(node);}return returnElements;};}
　　else {getElementsByClassName = function (className, tag, elm) {
　　tag = tag || "*";elm = elm || document;var classes = className.split(" "),classesToCheck = [],
　　elements = (tag === "*" && elm.all)? elm.all : elm.getElementsByTagName(tag),current,returnElements = [],match;
　　for(var k=0, kl=classes.length; k<KL; k+="1){classesToCheck.push(new" regexp(?(^|\\s)?="" classes[k]="" +="" ?(\\s|$)?));}<="" p="">
　　for(var l=0, ll=elements.length; l
　　for(var m=0, ml=classesToCheck.length; m
　　match = classesToCheck[m].test(current.className);
　　if (!match) {break;}}
　　if (match) {returnElements.push(current);　}}return returnElements;};}
　　return getElementsByClassName(className, tag, elm);};