Datasheet

Chapter 1: AJAX Technologies

var firstNameElement = employeeInfo.childNodes[0];

var firstname = firstNameElement.firstChild.nodeValue;

var lastNameElement = employeeInfo.childNodes[1];

var lastname = lastNameElement.firstChild.nodeValue;

var employeeIdElement = employeeInfo.childNodes[2];

var employeeid = employeeIdElement.firstChild.nodeValue;

var departmentNameElement = employeeInfo.childNodes[3];

var departmentname = departmentNameElement.firstChild.nodeValue;

Finally, it instantiates and returns an employee object with the returned firstname , lastname ,

employeeid , and departmentname :

return new employee(firstname, lastname, employeeid, departmentname);

JSON

One of the main tasks in an AJAX-enabled application is to serialize client/server-side objects into the

appropriate format before data is sent over the wire and to deserialize client/server-side objects

from an appropriate format after data is received over the wire. In general there are two common

data- interchange formats: XML and JSON. XML format was discussed in the previous section. Now let’s

move on to the second common data-interchange format: JSON.

JavaScript Object Notation ( JSON ) is a data-interchange format based on a subset of the JavaScript lan-

guage. The following sections present the fundamental JSON concepts and terms.

object

A JSON object is an unordered, comma-separated list of name/value pairs enclosed within a pair of

braces. The name and value parts of each name/value pair are separated by a colon (

: ). The name part

of each name/value pair is a string; and the value part is an array, another object, a string, a number,

true , false , or null .

array

A JSON array is an ordered, comma-separated list of values enclosed within a pair of square brackets

(

[ ] ). Each value is an array, another object, a string, a number, true , false , or null .

string

A JSON string is a collection of zero or more Unicode characters enclosed within double quotes ( “ “ ).

You must use a JSON string to represent a single character, and the character must be in double

quotes. You must use the backslash character (

\ ) to escape the following characters:

❑ Quotation mark ( \" )

❑ Solidus ( \/ )

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