Wednesday, November 29, 2006

What is AJAX

What is AJAX? No I am not talking about the household cleanser, I am talking about Asynchronous JavaScript and XML, a set of technologies is used to create interactive web applications. It is used in Google Maps, the table sorting capabilities of Gmail, and many mashup applications.

AJAX is primarily comprised of the following technologies:
  • HTML + CSS for presenting information
  • JavaScript for dynamically interacting with the information presented
  • XML, XSLT and the puzzlingly-named XMLHttpRequest object to manipulate data asynchronously with the Web server.

According to Ask Dave, XML, XSLT, and the XMLHttpRequestor make up the set of application programming interfaces (APIs) that allow Web applications to transfer data with a Web server using the standard HTTP protocol. "In a nutshell, this alphabet soup works together to allow JavaScript scripts to send data requests to the server and receive responses, all without having to load or reload a page."

In Enhancing Web Life with AJAX, November/December 2006 issue of MLA News, Win Shih explains that AJAX is a set of tools for rapid communication between web browsers and servers. "Instead of waiting for the users to click on a link or submit data, AJAX lets the browser communicate behind the scense with the web server each time new data is entered or received, eliminating the need to refresh or reload an edited wep page."

Another common example of AJAX in action is online shopping sites that allow you to drag and drop your items into your shopping cart or quickly updating and calculating shipping fees (without refreshing the whole page) when you type in your address. According to Shih, libraries and library vendors are lagging behind and have yet to really incorporate AJAX into their web sites and their products. There could be many reasons for this. It could be because it is a relatively new trend in web technologies and libraries (especially those within large institutions with rigid IT departments) have yet to adopt them. Other reasons might be that AJAX support is browser specific and security issues.

However, it does offer a lot of promises and opportunities for creating enhanced user centered services and support. Shih lists several library systems and vendors already using AJAX and I found some that either use AJAX or are looking at using it.

  • Georgia Public Library Service -AJAX enabled OPAC called PINES
  • Virginia Tech -AJAX enabled OPAC
  • New York University Division of Libraries - has a job opening for a programmer/analyst who must have "current knowledge of important library standards and protocols" and "recent experience designing and developing web based user interfaces using technologies such as XHTML, JavaScript, AJAX..."
  • Internet Librarian 2006 Conference -Workshop #5 dedicated to AJAX in libraries (handout available)
  • Innovative Interfaces - Encore, a unified search and access tool, uses AJAX among other Web 2.0 technologies
  • Polaris -has online catalog system based on AJAX
  • OCLC -DeweyBrowser uses AJAX to help users search for books in WorldCat

Like every tool it, AJAX may not work for everything and in every situation, but given the recent buzz about it on the Internet and its use in mashups, it is a good idea to have an idea of what it does and what it might be able to do for your situation. Just because you aren't a programmer doesn't mean you shouldn't know it exists.


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The Krafty Librarian has been a medical librarian since 1998. She is currently the medical librarian for a hospital system in Ohio. You can email her at: