EL expression in c:choose, can't get it working - jsf

Question

I'm trying something (JSF2) like this:
<p>#{projectPageBean.availableMethods}</p>
<c:choose>
<c:when test="${projectPageBean.availableMethods == true}">
<p>Abc</p>
</c:when>
<c:otherwise>
<p>Xyz</p>
</c:otherwise>
</c:choose>
But this doesn't seem to work, although the EL expression in the top paragraph changes from false to true, the next paragraph always shows Xyz?
I also tried to change the test to:
${projectPageBean.availableMethods}
But still the same problem!

Answer 1

First and foremost: JSTL tags runs during view build time, not during view render time.
Your concrete problem suggests that #{projectPageBean} is been set during view render time, such as would happen when definied as <ui:repeat var>, <h:dataTable var>, <p:tabView var>, etc. It's thus null during view build time.
In that case, you should not be using a view build time tag to conditionally render HTML. You should instead use a view render time component to conditionally render HTML. As first choice, use <ui:fragment>:
<p>#{projectPageBean.availableMethods}</p>
<ui:fragment rendered="#{projectPageBean.availableMethods}">
<p>Abc</p>
</ui:fragment>
<ui:fragment rendered="#{not projectPageBean.availableMethods}">
<p>Xyz</p>
</ui:fragment>
By the way, there's in Facelets no need to switch between #{} and ${}. In contrary to JSP, in Facelets the ${} behaves exactly the same as #{}. To avoid potential confusion and maintenance trouble, I recommend to stick to #{} all the time.
See also:
Conditional rendering of non-JSF components (plain vanilla HTML and template text)