DataScroller not working when inside a <a4j:repeat> tag?

[peter.falken]

I'm using a code similar to this and it works:

<rich:tabPanel>
<a4j:repeat value="#{Vars}" var="var">
       <rich:tab header="#{var}" switchType="ajax">
            <rich:dataTable value="#{foo(var)}" var="f" rows="10" rowKeyVar="rowNum">
                 <f:facet name="header">
                    <rich:dataScroller boundaryControls="hide" fastControls="hide" />
                 </f:facet>
                 <rich:column>
                      <f:facet name="header">#</f:facet>
                      <h:outputText value="#{rowNum+1}." />
                 </rich:column>
          </rich:dataTable>
  </rich:tab>
</a4j:repeat>
</rich:tabPanel>

But if I switch it a little and put the DataScroller outside the DataTable and use the "for" attribute it doesn't work.

Can anybody help me out? - maybe I'm doing something wrong.

<rich:tabPanel>
<a4j:repeat value="#{Vars}" var="var">
       <rich:tab header="#{var.name}" switchType="ajax">
               <rich:dataScroller boundaryControls="hide" fastControls="hide" for="#{var.name}_table" />
            <rich:dataTable id="#{var.name}_table"  value="#{foo(var)}" var="f" rows="10" rowKeyVar="rowNum">
                 <rich:column>
                      <f:facet name="header">#</f:facet>
                      <h:outputText value="#{rowNum+1}." />
                 </rich:column>
          </rich:dataTable>
  </rich:tab>
</a4j:repeat>
</rich:tabPanel>

[bleathem]

This is likely due to your use of EL in the for attribute.  I don't think that will resolve (I'd have to look at the code to be sure).

Try using c:forEach instead, that gets executed earlier in the lifecycle than a4j:repeat (although it doesn't work well when your collection is truly dynamic).

[peter.falken]

Thanks Brian.

When using <c:forEach> it works - is this the correct behavior or is this an issue/bug with the current version of RichFaces?

The issue being that the EL is not resolved while using <a4j:repeat>

Luis

[bleathem]

Remember the JSTL tags are evaluated at the time the component tree is built, where as the ui/a4j:repeat tags are evaluated when the response is rendered.  This is a fundamental difference.  The JSTL tag forces the evaluation of the value expression when building the component tree.  Whereas at render time, the DataScroller Renderer [1,2] just sees a String.

To get the DataScroller's for attribute [1] to work with a value expression, it's type would have to be Changed to ValueExpression, and the Renderer changed to evalueate that expression (using the RenderKitUtils#evaluateAttribute method [3]).

Feel free to experiment with this and make sure it works.  If it does, please file a jira issue and an associated GitHub Pull Request (https://community.jboss.org/wiki/GuideToUsePullRequestsWithGitHubAndJIRA)

[1] https://github.com/richfaces/richfaces/blob/master/framework/src/main/java/org/richfaces/ui/iteration/dataScroller/AbstractDataScroller.java#L150

[2] https://github.com/richfaces/richfaces/blob/master/framework/src/main/java/org/richfaces/ui/iteration/dataScroller/DataScrollerUtils.java#L99

[3] https://github.com/richfaces/richfaces/blob/master/framework/src/main/java/org/richfaces/renderkit/RenderKitUtils.java#L786