The ajax theme extends the xhtml theme with AJAX features. The theme uses the popular DOJO AJAX/JavaScript toolkit. AJAX features include:
- AJAX Client Side Validation
- Remote form submission support (works with the submit tag as well)
- An advanced div template that provides dynamic reloading of partial HTML
- An advanced a template that provides the ability to load and evaluate JavaScript remotely
- An AJAX-only tabbedPanel implementation
- A rich pub-sub event model
- Interactive autocomplete tag
See also: Ajax tags
Browser Compatibility
AJAX (as a technology) uses a browser-side scripting component that varies between browers (and sometimes versions). To hide those differences from the developer, we utilize the dojo toolkit (http://www.dojotoolkit.org). Several browsers are supported by dojo, and any UI's created with the ajax theme should act the same way for supported browsers. The supported browsers are:
- IE 5.5+
- FF 1.0+
- Latest Safari (on up-to-date OS versions)
- Latest Opera
- Latest Konqueror
Extending the AJAX Theme
The wrapping technique utilized by the ajax theme is much like xhtml theme, but the controlheader.ftl is a wee bit different.
The header provides for AJAX Client Side Validation by checking if the validate attribute is set to true. If it is, a validation request is made on each onblur event for a HTML Struts Tags. Some people don't like the onblur behavior; they would rather a more advanced timer (say, 200ms) be kicked off after every keystroke. You can override this template and provide that type of behavior if you would like.
Special Interest
Three ajax_xhtml templates of special interest are head, div, and a.
In addition to these templates, be familiar with the ajax event system provided by the framework and Dojo.