AJAX TiP:

Like DHTML, LAMP, and SPA, "Ajax" is not a technology in itself, but a term that refers to the use of a group of technologies.

The AJAX sequence diagram that shows how the XMLHttpRequest is used.

Image URL Info. http://www.modelworks.com/images/ajax.png

Uses of AJAX

AJAX has many potential uses. Here are a few of them:

• Updating page information
• Real-time data validation
• Obtaining data for a control
• Responding to server events
• Pushing data to the client
• Real-time interaction
• Real-time monitoring
• Auto completion

AJAX requires both client side and server side code. This means that you have more technology to master. It also means that you will have to rely on client side technology which you do not control. At a minimum it means knowing DHTML, JavaScript and at least one server side technology.

The AJAX Toolkit Framework (ATF) Project URL info. :

http://www.eclipse.org/proposals/atf/

The Zimbra Ajax Toolkit :

Zimbra is contributing to the Open Ajax Initiative by providing open access to the Zimbra Ajax Toolkit (AjaxTK).

Zimbra has used AjaxTK to push the envelope of what we think of as a Web page by developing a complete online Collaboration Suite, including enterprise-class e-mail, calendar, and contacts.

The AjaxTK squeezes the responsiveness gap between a Web-based application and a standard desktop-based application to near zero.

Dojo Documentation URL info. :

http://files.zimbra.com/website/docs/Zimbra%20AJAX%20TK%20Whitepaper.pdf

The Dojo Ajax Toolkit :

Is a runtime tool which will be supported in Eclipse's Ajax Toolkit Framework (ATF).

Dojo is a community project designed to unify the efforts of the JavaScript and Dynamic Hypertext Markup Language (DHTML) communities in a single direction by building a standard JavaScript library.

The community realized it wouldn't get far without people working together, so three separate predecessor tool kits were unified to form the Dojo Foundation, which owns and maintains the code. Dojo has several optional packages, including an Ajax edition; an I/O edition; and a "Kitchen Sink" edition, which includes the entire tool set.

Dojo Documentation URL info. :
http://dojotoolkit.org/docs

Eclipse's Ajax Toolkit Framework :

Open Ajax Initiative components

Hidden Frames in AJAX :--

This Technique is a longstanding trick of developers to return information from the server
but keep it invisible to the user.

It uses a standard frameset with two frames to open two separate pages (or more if required),
the first being visible to the user and the second being made invisible by setting its width or height to zero.

The hidden frame can be used to send requests and retrieve data from the server,
but the data is placed in the visible frame only when needed.

Constituent technologies

The Ajax technique uses a combination of:

• XHTML (or HTML) and CSS, for marking up and styling information.
• The DOM accessed with a client-side scripting language, especially ECMAScript implementations such as JavaScript and JScript, to dynamically display and interact with the information presented.
• The XMLHttpRequest object is used to exchange data asynchronously with the web server. In some Ajax frameworks and in certain situations, an IFrame object is used instead of the XMLHttpRequest object to exchange data with the web server, and in other implementations, dynamically added <script> tags may be used.
• XML is sometimes used as the format for transferring data between the server and client, although any format will work, including preformatted HTML, plain text, JSON and even EBML. These files may be created dynamically by some form of server-side scripting.

Bandwidth usage:-

Ajax web pages can appear to load relatively quickly since the payload coming down is much smaller in size.

AJAX Data Insertion:--

Using Ajax is all about inserting fresh data into a page without having to
reload that page, and using the Dynamic HTML (DHTML) technique of inserting
text into a " div " or a " span " is very popular. Want to display some new
data? Fetch it from the server, pop it into a " div ", and pow!, there you are.
The " div " element is the most popular, but don’t forget that it’s a block element
and so takes up its own line(s) in the browser. If you want to place new
text inline, consider " span ".

AJAX CHAT:--

Ajax excels at updating Web pages without refreshing the displayed
page, it’s a great choice for Web-based chat programs, where many users can
chat together at the same time.

AJAX:-

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