binding and el expression in datatable

[sudharshan tettu]

Hi
how can we pass an el expression to datatable in xhtml?

For example
<c:set var="tempparam" scope="request" value="#{backingbean.nameofbinding}" />
<h:datatable binding="#{tempparam}" ....></h:datatable>

i get that tempparam from some other request object.How can we set it as an el expression for binding instead of plain string.


Thanks
Sudharshan Tettu

[Tim Holloway]

Well, first off, get rid of the JSTL. JSTL and JSF don't go together well, and you don't need JSTL for JSF anyway. I also discourage using "binding" on controls unless you actually intend on dynamically rearranging the UI. Value binding is simpler, cleaner and doesn't require you to burden your backing bean with arcane JSF-specific code.

Secondly, there's absolutely no problem with using a symbolic value in EL expressions. I have lots of cases where I do a <ui:include> that passes the name of a component to the included xhtml to be dynamically substituted using the <ui:param> element. The only limitation is that while most JSF attributes may be EL expressions, some have to be fixed text, so it's always good to check the documentation on the tag in question. Things like value bindings, however, usually can be EL, so that's not much of a problem.

[sudharshan tettu]

Am not getting you could you please give me an example how can I dynamically substitute the value for binding at runtime using ui:param
Thanks

[Tim Holloway]

                <h:panelGroup id="localList" rendered="#{search.criteria.geoScope le 0}">
                    <ui:include src="/WEB-INF/layout/listing.xhtml">
                        <ui:param name="title" value="Advanced Search Local - #{search.inTown.rowCount} Matches" />
                        <ui:param name="searchResults" value="#{search.inTown}" />
                    </ui:include>
                </h:panelGroup>
                <h:panelGroup id="stateList" rendered="#{search.criteria.geoScope le 1}">
                    <ui:include src="/WEB-INF/layout/listing.xhtml">
                        <ui:param name="title" value="Advanced Search In-State - #{search.inState.rowCount} Matches" />
                        <ui:param name="searchResults" value="#{search.inState}" />
                    </ui:include>
                </h:panelGroup>

Excerpt from included file listing.xhtml

                   <rich:dataTable id="resultsList"
                        styleClass="listingPanel"
                        headerClass="listingHeader"
                        rows="10" columnClasses="listingCol1,listingCol2,listingCol3"
                        value="#{searchResults}" var="item"
                    >
                     <h:column>
                        <h:outputText value="#{item.description}/>
                    </h:column>
... and so forth       

">

[sudharshan tettu]

Thanks Tim ,but my issue with binding for example we customized it like this
<ht:datatable binding="#{mytable}">
<h:column>
#{mutable.rowIndex}
</h:column>
</ht:datatable>


And in my datatable it's just an xhtm page where I would be invoking the jsf datatabl with some customization.
Like


<h:datatable binding="#{binding}">
<ui:insert/>
</h:datatable>

But my problem is the binding attr we used inside the column is not getting resolved when we pass it like that into the XHTML(the tag)

[Tim Holloway]

<ui:insert> is really not a good way of doing stuff like that. Use ui:insert for things like simple string values and use ui:include for more complex elements.

[sudharshan tettu]

hey tim I got it, let me try with ui:include and other workarounds