Page 60 - DCAP312_WEB_TECHNOLOGIES_II

Web Technologies-II

Notes
ActiveX and other plug-in technologies like .NET’s Web Deploy and even the new XAML
Browser Applications have to be considered by any company targeting the Microsoft
platform. If you only need to support IE on Windows then they offer superior interactivity
and a well-supported programming environment. However, Atalasoft was committed to our
client-side working on every major browser and platform without any plug-ins or special
security settings, so these were never really an option for us.
AJAX is a term used to describe applications that use JavaScript, Dynamic HTML, and some
sort of mechanism to contact the server for updates without needing a post-back. The effect is
that the HTML page appears to update in place without causing it to blank out and refresh.
AJAX itself is an acronym meaning Asynchronous JavaScript and XML, and describes the
technique, not a specific tool or implementation – there is a AJAX player, for instance.

Although the name “AJAX” caught on very quickly, it does not really describe how this
technique is actually done, since XML is not always used. The X in AJAX refers to both
the format of the server communication (XML) and the browser function used to initiate
the connection (XMLHttpRequest). Atalasoft actually uses neither, opting instead for
communicating by posting forms in the background via an IFRAME and receiving JavaScript
and JSON (JavaScript Object Notation).
• To us, AJAX offers the following benefits over the other technologies:
• Only needs features native to the browser, HTML and JavaScript. All modern browsers
support it. No plug-ins required.
• If necessary, you can write it to degrade nicely on older browsers that do not support
it.
• It can be styled with CSS and integrates naturally with JavaScript.
• Since it is built on top of HTML and uses the DOM to represent itself, ASP.NET has
natural ways for keeping its state via a post-back.
• It uses open technologies well understood by web developers.
Three years later, the technique we chose is gaining great acceptance. In 2005, after Google
released Google Maps and Suggest (and GMail starting getting more and more interactive),
many developers realized that HTML and JavaScript had come a long way, and were willing
to bet on the technology (since it was good enough for Google). Gartner is predicting that
by 2010, at least 60% of new application development projects will include Rich Internet
Applications (RIA) technology such as AJAX.

The second annual AJAXWorld in NYC was in March this year, and according to the keynote,
there are over a hundred AJAX frameworks on the market (many open-source). Google,
Yahoo, and Microsoft all have open frameworks and tools available, but there are other
popular ones such as Dojo and MochiKit, not to mention many proprietary ones.

<embedsrc=“http://www.youtube.com/v/_s1gtVwMMAg”width=“425”height=“350”type=
“application/x-shockwave-flash” wmode= “transparent” /></embed />

For ASP.NET developers, Microsoft publishes ASP.NET AJAX (formerly Atlas), which is a
combination of their open-source AJAX JavaScript library and server-side ASP.NET controls to
interact with them. Our AJAX implementation is fully compatible with it (since we designed
it to be compatible with ASP.NET from the start). One common theme at AJAXWorld is that
it was better to adopt AJAX components that operated within a framework. This is because
although AJAX is thought of as a client-side technology, its true benefit comes from tight
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