alterrnate爲accesing的DOM元素

Question

我有一個情況我需要訪問的表頭複選框 我與

document.getElementsByClassName("table_th_label_div")[0]; 

這樣做，但一些舊的瀏覽器不支持.getElementsByClassName我需要爲同一

替代appproach好心幫 預先感謝

Answer 1

這solution可能會有幫助。這是在純javascript中實現的getElementsByClassName函數，可在IE中使用。

/* 
    Developed by Robert Nyman, http://www.robertnyman.com 
    Code/licensing: http://code.google.com/p/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<il; i+=1){ 
       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<jl; j+=1){ 
       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|$)")); 
      } 
      for(var l=0, ll=elements.length; l<ll; l+=1){ 
       current = elements[l]; 
       match = false; 
       for(var m=0, ml=classesToCheck.length; m<ml; m+=1){ 
        match = classesToCheck[m].test(current.className); 
        if (!match) { 
         break; 
        } 
       } 
       if (match) { 
        returnElements.push(current); 
       } 
      } 
      return returnElements; 
     }; 
    } 
    return getElementsByClassName(className, tag, elm); 
};