Mark S. Hicks

  Good web sites separate themselves from great ones by their functionally. A poor performing slowly updating and thin informational contented site bleeds interest fast. Everyone that browses the internet today becomes an instant critic. No longer is good looking good enough on the net today; one must have flash, pop and content. If a site is hit, it must delivery positive feedback in less that 30 seconds or the audience is lost to another site or search. Today’s web designers are increasingly more perceptive and creative with advanced techniques and web tools. One of the hottest web scripting tools gaining new ground is Asynchronous JavaScript and XML or AJAX.

  AJAX is used for creating interactive web applications by asynchronously requesting small bits of extra data from the server and loading it in the background without adversely affecting the overall behavior of the existing page. JavaScript is the most common scripting language used with AJAX function calls. Data are sent and retrieved using an XML HTTP request object. AJAX is open standard, cross plat-formed and supported with free frameworks and libraries. Ajax is not a technology in itself, but the use of a group of technologies. The combined technologies function as an Inner-Browser with navigation occurring within a single page, as a application interface.

  The intent of AJAX style programming is to reduce the page loading requirements of HTML/HTTP web pages while delivering additional information to a browser when someone clicks on a button or moves the mouse cursor over a part of the page, without refreshing the entire page . AJAX implementation allows complex, intuitive, dynamic, data-centric user interfaces in web pages. The combined technology inner-work of AJAX supports interactions of real-time form data validation, via XML, with auto completion as the user types, and load on demand HTML by loading more data in the background for quick access.

  An example of a site that uses AJAX is the online video rental site Netflix. The site automatically pops up a movie's synopsis, with a thumbnail image of the movie poster, when a customer moves the cursor over titles in a list of search results. Interactive scripting such as this allows the site to provide detailed content without the required loading to a brand-new page if a user wants to find out more about a movie. The user has instant feedback without waiting for a completely new page thus dramatically speeding up the site visit. (2007) Wikipedia

  AJAX supports sophisticated user interface controls, page effects with real-time data refresh and server push. The data can be polled from a server for up-to-date-data such as a stock market ticker. These web effects can be accomplish without the need to refresh the entire web page. AJAX scripts can be used to mix external data using server side proxies with ones own server applications and third party data; this mix of data is called Mashups. Additionally AJAX techniques can be used to create single-page applications that run like a typical desktop application environment. (2007) Sun Microsystems, Inc

  The power of AJAX is apparent with the generation of HTML locally within the browser while utilizing JavaScript calls to bring down only the small amount of actual data needed. Web pages appear to load quicker due to the fact the overall layout does not have to be completely redrawn. With Ajax, the HTML of the page can be produced locally in the browser, with load on demand content. AJAX Web-based applications can load event handlers then load the functions on the fly, which significantly cuts down the bandwidth consumption for web applications.

  Bandwidth speed, navigation and content all vie for top billing in web site creation. Web tools such as AJAX, Active X, and scripts help balance the resources. How the web page interacts with the user is paramount to the success of the site.

  In an article by John Zaner an associate professor, from University of Southern Maine, Gorham he speaks of user interaction with content feedback and how it can be accomplished with client and server-side scripts. Client-side scripts use languages like JavaScript that are included in the HTML code and processed by the web browser. Server-side scripts use languages like PHP, ASP and Perl and are processed by the web server. Zaner states that without scripts, web pages are a "one-way street" limited to displaying static information to the user.

  Server-side scripts can interact with other files and databases to store and retrieve information. Server-side script web applications include guest books, discussion groups, search engines, and online businesses. Client-side scripts use the client's computer to process instructions that can be handled locally reducing the load on the server, speeding up the process by reducing the number of times the browser needs to connect to the server. Client-side scripts include form pre-processing, online games, and can display customization with out reloading the page.

  Rosemarie Wise a self-proclaimed "web enthusiast" says about Server Side Validation is “the best thing about validating the input on the server is that your visitors don't need to meet any specific browser requirements. Of course validating on the server side can be much more demanding on server resources, but it does help to catch any invalid data that comes into the script directly or happens to make it past any client side filters you created.”

(2007) Sun Microsystems, Inc

References

Murray, Greg,  June 9, 2005; updated October 2006 (Asynchronous JavaScript Technology and XML (Ajax) With the Java Platform) (2007) Sun Microsystems, Inc http://java.sun.com/developer/technicalArticles/J2EE/AJAX/

Wikipedia® November 2007 http://en.wikipedia.org/wiki/Ajax_%28programming%29

Wise, Rosemarie, Tue 25th Dec, 2001 http://websiteowner.info/articles/cgi/whichside.as

© 2000-2007 Rosemarie Wise

Zaner, John,  associate professor, Department of Technology, University of Southern Maine Gorham, Copyright © 2007 ProQuest LLC http://proquest.umi.com/pqdweb?did=1129268131&sid=10&Fmt=3&clientId=2606&RQ T=309&VName=PQD