Using Ajax in ASP.NET application -2

In part 1 of this post we saw our response returning us a simple text which was holding a single value.

But what if it is returing multiple values and it using some characters like | (pipe) or say semicolon for separating one value from another.

In this case, we need to make use of javascript string functions to get each and every value.

Here then our application should understand what ; and | or say , mean and what if their order changes.

So now we can have our responses send as XML so that we can make use of XMLDOM to parse through the response. Which infact would be quite easy and efficient.

Let’s update our application

https://nishantrana.wordpress.com/2007/10/25/using-ajax-in-aspnet-application/

Things we need to change are

1)  Change doUpdate function

function doUpdate()

{

if(xmlHttp.readyState==4)

{ // replacing reponseText with responseXML to get the xml DOM tree reference 

var xmlDoc=xmlHttp.responseXML; // parsing through the response using dom methods

var firstName=xmlDoc.getElementsByTagName(“first”)[0].firstChild.nodeValue;

var lastName=xmlDoc.getElementsByTagName(“last”)[0].firstChild.nodeValue;

document.getElementById(“lblInfo”).firstChild.nodeValue=firstName+” “+lastName; }

 }

In the above case the response we are recieving from server is this, which is in xml

<?xml version=”1.0″?>
<name><first>Mickey</first><last>Mouse</last>
</name>

2) Now we will change Default2.aspx to send us response back in xml.

protected void Page_Load(object sender, EventArgs e){ // this will inform our webpage about responses being sent as XML and not text

 Response.AddHeader(“Content-Type”, “text/xml;charset=UTF-8”);

Response.Write(“<?xml version=\”1.0\” encoding=\”utf-8\”?><name><first>Mickey</first><last>Mouse</last> </name>”);  

}

Now we can run our application and see our label’s text changing to Mickey Mouse. 

Bye