base is null

[Dave]

Hi, 
  <h:panelGroup rendered="#{bean.foo != null}">
   
  <t:tree value="#{bean.foo.treeModel}">
  ...
  </t:tree>
   
  </h:panelGroup>
   
  bean is not null.
  Why did I got the following error:
   
  javax.faces.el.PropertyNotFoundException: Base is null: .foo
        at 
org.apache.myfaces.el.ValueBindingImpl.resolveToBaseAndProperty(ValueBindingImpl.java:477)
        at 
org.apache.myfaces.el.ValueBindingImpl.setValue(ValueBindingImpl.java:251)
        at 
org.apache.myfaces.custom.tree.taglib.TreeTag.doStartTag(TreeTag.java:349)
   
  thanks!
  Dave

       
---------------------------------
Never miss a thing.   Make Yahoo your homepage.