Conditional variable definition in JSF

Question

i want to change the variable value based on a condition so i tried the following:

<h:head>

    <ui:param name="userCase" value="Insert" />

    <ui:fragment rendered="#{employee.employeesBulkInsert==false}">
       <ui:param name="userCase" value="Update" />
    </ui:fragment>

       <title>#{userCase} Employee </title>

</h:head>

but it doesn't work in the update case, it shows an empty string, any ideas why ?

i know that there are other solutions like defining the variable in the backing bean, or make the conditional ui fragment on the title tag directly, but i want to know why the above is not working, please advise, thanks.

Berkly

It's very good practice to say what behaviour you are experiencing (an error? What's the message? Not the output you expect? What you were expecting?), not just "doesn't work". – Tuxedo

sure, i will update the question :) – Berkly

Answer 1

The <ui:fragment> is a render-time tag while the <ui:param> is a tag handler (tag handlers are easily recognizeable by the absence of the rendered attribute). So when the view get built, the <ui:param> is set, regardless of the outcome of <ui:fragment>. The rendered attribute of <ui:fragment> is only evaluated when the already-built view is to be rendered.

You want to make the condition using a tag handler instead, such as JSTL <c:if>.

<ui:param name="userCase" value="Insert" />

<c:if test="#{not employee.employeesBulkInsert}">
    <ui:param name="userCase" value="Update" />
</c:if>

(note that I removed the unnecessary boolean ==false comparison)

Cubit

Answer 2

Try using JSTL instead:

<c:set var="userCase" value="Insert" />
<c:if test="#{employee.employeesBulkInsert}">
    <c:set var="userCase" value="Update" />
</c:if>

Tutorial here: http://www.ibm.com/developerworks/java/library/j-jstl0211/index.html

Sup