Datasheet

Chapter 1: AJAX Technologies

Next, it invokes the WriteStartElement method on the XmlWriter to write a new element named

employeeInfo into the XmlWriter , which in turn writes this element into the StringWriter :

xw.WriteStartElement(“employeeInfo”);

This element will act as the document element of the XML document. Every XML document must have a

single element known as the document element that encapsulates the rest of the XML document.

Page_Load then invokes the WriteElementString method four times to write three elements named

firstName , lastName , employeeId , and departmentName with the specified values into the

XmlWriter , which in turn writes these elements into the StringWriter :

xw.WriteElementString(“firstName”, “Shahram”);

xw.WriteElementString(“lastName”, “Khosravi”);

xw.WriteElementString(“employeeId”, “22223333”);

xw.WriteElementString(“departmentName”, “Some Department”);

Next, Page_Load invokes the ToString method on the StringWriter to return a string that contains

the entire XML document:

xml = sw.ToString();

Then, it sets the Content-Type HTTP response header to the value text/xml to signal the client code

that the server response contains XML data:

Response.ContentType=”text/xml”;

Next, it writes the string that contains the XML data into the server response output stream:

Response.Write(xml);

Finally, it invokes the End method on the Response object to end the response right away and, consequently,

to send the XML document to the client, bypassing the normal rendering routine of the current page:

Response.End();

Now let’s walk through the implementation of the deserialize JavaScript function in Listing 1-3 . This

function invokes the

responseXML property on the XMLHttpRequest object to return the XML

document:

var response = request.responseXML;

var employeeInfo = response.documentElement;

Then, it uses the XML API to extract the employee’s firstname , lastname , employeeid , and

departmentname from the XML document:

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