Make use of the rendered
attribute. It accepts a boolean expression. You can evaluate the datatable’s value inside the expression with help of the EL’s empty
keyword. If it returns false
, the whole component (and its children) won’t be rendered.
<h:outputText value="Table is empty!" rendered="#{empty bean.list}" />
<h:dataTable value="#{bean.list}" rendered="#{not empty bean.list}">
...
</h:dataTable>
For the case you’re interested, here are other basic examples how to make use of the EL powers inside the rendered
attribute:
<h:someComponent rendered="#{bean.booleanValue}" />
<h:someComponent rendered="#{bean.intValue gt 10}" />
<h:someComponent rendered="#{bean.objectValue eq null}" />
<h:someComponent rendered="#{bean.stringValue ne 'someValue'}" />
<h:someComponent rendered="#{not empty bean.collectionValue}" />
<h:someComponent rendered="#{not bean.booleanValue and bean.intValue ne 0}" />
<h:someComponent rendered="#{bean.enumValue eq 'ONE' or bean.enumValue eq 'TWO'}" />
See also:
- Java EE 7 tutorial – Expression Language – Operators