step3_3.html

ajax快速入门,主要讲解原理与部门实现

blog title:<font color=blue><div id="blogtitle"></div></font><br>
link:<font color=blue><div id="link"></div></font><br>
description:<font color=blue><div id="description"></div></font><br>
managingEditor:<font color=blue><div id="managingEditor"></div></font><br>
generator:<font color=blue><div id="generator"></div></font><br>
blogitem:<div id="blogitem"></div>
<SCRIPT LANGUAGE="JavaScript">
var isIE = (navigator.userAgent.indexOf("MSIE")!=-1); 

// check for XPath implementation
if(!isIE) {
   // prototying the XMLDocument
   XMLDocument.prototype.selectNodes = function(cXPathString, xNode) {
      if( !xNode ) { 
        xNode = this; 
      } 
      var oNSResolver = this.createNSResolver(this.documentElement)
      var aItems = this.evaluate(cXPathString, xNode, oNSResolver, 
                   XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)
      var aResult = [];
      for( var i = 0; i < aItems.snapshotLength; i++) {
         aResult[i] =  aItems.snapshotItem(i);
      }
      return aResult;
   }

   // prototying the Element
   Element.prototype.selectNodes = function(cXPathString) {
      if(this.ownerDocument.selectNodes) {
	     return this.ownerDocument.selectNodes(cXPathString, this);
      }
      else{throw "For XML Elements Only";}
   }


   // prototying the XMLDocument
   XMLDocument.prototype.selectSingleNode = function(cXPathString, xNode) {
      if( !xNode ) { xNode = this; } 
      var xItems = this.selectNodes(cXPathString, xNode);
      if( xItems.length > 0 ) {
         return xItems[0];
      }
      else {
         return null;
      }
   }
   
   // prototying the Element
   Element.prototype.selectSingleNode = function(cXPathString) {	
      if(this.ownerDocument.selectSingleNode) {
         return this.ownerDocument.selectSingleNode(cXPathString, this);
      }
      else{throw "For XML Elements Only";}
   }
}		

var bloglist=new Array();
var xmlHttp;

if(typeof XMLHttpRequest != "undefined") {
    xmlHttp=new XMLHttpRequest();
    xmlHttp.open("GET", "test.xml", true);
}
else {
    try {
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
        xmlHttp.open("GET", "http://www.blogjava.net/dlee/Rss.aspx", true);
    }
    catch(e) {
        xmlHttp = null;
        alert("Can't create XMLHTTP object!");
    }
}

xmlHttp.onreadystatechange=function() {
	if (xmlHttp.readyState==4) {
		var xmldom=xmlHttp.responseXML;
		var channel=xmldom.documentElement.selectSingleNode("channel");

		document.getElementById("blogtitle").innerHTML = channel.selectSingleNode("title/text()").nodeValue;
		document.getElementById("link").innerHTML = channel.selectSingleNode("link/text()").nodeValue;
		document.getElementById("description").innerHTML = channel.selectSingleNode("description/text()").nodeValue;
		document.getElementById("managingEditor").innerHTML = channel.selectSingleNode("managingEditor/text()").nodeValue;
		document.getElementById("generator").innerHTML = channel.selectSingleNode("generator/text()").nodeValue;
		
		items = channel.selectNodes("item/description/text()");
		for(var i=0; i<items.length; i++) {
		    bloglist[bloglist.length]= items[i].nodeValue;
		}

		document.getElementById("blogitem").innerHTML="<div id=\"blogitem\">"+bloglist[0]+"</div>";
	}
}
xmlHttp.send(null);

</SCRIPT>