TECHNOLOGIES USED IN AJAX

The term Ajax has come to represent a broad group of web technologies that can be used to implement a web application that communicates with a server in the background, without interfering with the current state of the page. In the article that coined the term Ajax, Jesse James Garrett explained that the following technologies are incorporated:

§  HTML or XHTML and CSS for presentation

§  the Document Object Model (DOM) for dynamic display of and interaction with data

§  XML for the interchange of data, and XSLT for its manipulation

§  the XMLHttpRequest object for asynchronous communication

§  PHP or another scripting language may be used on the server

§  JavaScript to bring these technologies together

§  SOAP may be used to dialog with the server.

Since then, however, there have been a number of developments in the technologies used in an Ajax application, and the definition of the term Ajax. In particular, it has been noted that JavaScript is not the only client-side scripting language that can be used for implementing an Ajax application; other languages such as VBScript are also capable of the required functionality. (However, JavaScript is the most popular language for Ajax programming due to its inclusion in and compatibility with the majority of modern web browsers.) Also, XML is not required for data interchange and therefore XSLT is not required for the manipulation of data. JavaScript Object Notation (JSON) is often used as an alternative format for data interchange,^] although other formats such as preformatted HTML or plain text can also be used