I read various examples on the web where an ajax call sent through a4j tags of ReachFaces 3 re-renders a jstl tag. In this example:
http://relation.to/Bloggers/UsingDynamicallyCreatedRichFacesTabPanelForSearchResults
an ajax call re-renders a c:foreach inside a rich:tabPanel (look at the code after "Add the next code just after the panel code:").
My question is: since the c:forEach tag is evaluated during view creation (like any other jstl tag), the portion of the view pointed by the reRender attribute is reconstructed from scratch on every ajax request?
Thanks a lot.
Nico
Looking at JSF lifecycle docs, more specifically the Restore View Phase and Render Response Phase parts, you can find what are you looking for:
Restore View Phase
If the request for the page is an initial request, the JavaServer Faces implementation creates an empty view during this phase and the life cycle advances to the render response phase. The empty view will be populated when the page is processed during a postback.
If the request for the page is a postback, a view corresponding to this page already exists. During this phase, the JavaServer Faces implementation restores the view by using the state information saved on the client or the server.
Render Response Phase
During this phase, the JavaServer Faces implementation delegates authority for rendering the page to the JSP container if the application is using JSP pages. If this is an initial request, the components represented on the page will be added to the component tree as the JSP container executes the page. If this is not an initial request, the components are already added to the tree so they needn't be added again. In either case, the components will render themselves as the JSP container traverses the tags in the page.
In short words, when you perform an Ajax request, you already have the view there. JSF will just search the components you want to rerender through it, just after their model have been updated, and update the view with their new values. In case of c:forEach, it's not a component, but a tag handler, so it's evaluated before that.
Related to the link you posted, have a look at this page about the difference between components and tag handlers. They just have different lifecycles, so take care when mixing them.