Richfaces supports AJAX functionality in a lot of it components. However a servlet filter is needed for correct functioning of partial page refreshes.
In this post we’ll show you how to add this filter and at the same time optimize Richfaces performance.
The following Richfaces filter is defined in the web.xml:
<filter> <filter-name>richfaces</filter-name> <display-name>RichFaces Filter</display-name> <filter-class>org.ajax4jsf.Filter</filter-class> <init-param> <param-name>forceparser</param-name> <param-value>false</param-value> </init-param> </filter>
What this filter does, is to ‘tidy’ all HTML HTTP Responses so that they are valid XHTML (thus XML compliant). This is needed as dynamic DOM updates in the browser need correct XML.
If you don’t define this filter, it is possible that you’ll not see your AJAX update being rendered on the screen, although you’ll see the html response coming back in eg. Firebug
Of course, parsing HTML incurs a performance overhead.
This can be minimized by setting the forceparser setting to false. In that case only AJAX responses will be ‘tidied’. In the other case all JSF responses are ‘tidied’. That is because the filter is mapped on the Faces servlet:
<context-param> <param-name>org.ajax4jsf.xmlparser.ORDER</param-name> <param-value>NEKO</param-value> </context-param> <context-param> <param-name>org.ajax4jsf.xmlparser.NEKO</param-name> <param-value>.*\..*</param-value> </context-param>
Here we say we only use the NEKO filter and it should be applied to all URLs (.)
There is more configuration possible, like using NONE for some pages that don’t need HTML correction to further speedup things if needed.
Example can be found at: http://jboss.com/index.html?module=bb&op=viewtopic&t=116231