Ajax (also known as Asynchronous JavaScript and XML) is the incredible conjunction of Web technologies allowing a site to provide interactivity that compares with many desktop applications. Ajax allows a Web application to provide updates and interactivity on a Web page without refreshing the entire Web page. That can make a site far more dynamic and responsive.

The problem with Ajax is that the Ajax system is literally invisible to search engines. Ajax technology relies on a browser to execute JavaScript code to retrieve additional information from the Web server and display it in the browser window — most often in a pop-up window. Search engine spiders will not execute any client-side code. That means that the content displayed by the Ajax technology is not seen by search engines.

Presently, there is no ideal way to adopt Ajax and yet continue to obtain good search engine placement. Web designers that adopt Ajax have the following options to ensure continued good placement:

❑       Duplicate content on general pages — Even though a user will primarily view Ajax content through pop-up windows or interactive retrieval, be sure to keep all content that is provided through the Ajax interface also available as standard HTML content elsewhere on your site. You may have to develop a custom component to accomplish this task on Joomla, but ultimately for SEO it would be worth it.

❑       Avoid using Ajax and JavaScript for navigation — When a search engine spider indexes a Web site, it uses the internal links to find the content of the site pages. Since JavaScript is not executed by the spiders, nearly all of the navigation links displayed via JavaScript menus or Ajax live con- tent retrieval will be invisible to the spider. Therefore, be sure to avoid using these technologies for your site navigation.

❑       Have Ajax content be a summary of a traditional page — Instead of making Ajax-specific content, have your Ajax extension provide a summary of traditional content. PHP can easily parse an HTML file, so your Ajax component could simply retrieve the content and reformat it for Ajax display. This would eliminate the need for any content duplication.

Ajax is so quickly gaining dominance as a method of providing site interactivity that the search engine will soon find a method by which site designers can signal to spiders the location of the content. Until that occurs, following these guidelines is the best way to adopt the new technology and keep a proper site ranking.

For the same reasons of invisibility to the spiders, you should be judicious in your use of Flash. While Flash can create an excellent impression on your visitor, Flash content is all but invisible to search engine indexing programs. Therefore, try to have a traditional HTML representation of all content, so the page is properly indexed by a search engine.