[jsr-314-open] #{compositeComponent.attrs....}

[Andy Schwartz]

Ken Paulsen wrote On 4/15/2009 12:14 PM ET:
> Page author does:
>
> <my:echoComp value="#{foo.bar}">
>
> Suppose in echoComp def they map "compositeComponent.attributes" to 
> "foo".  Then if the component attempts to evaluate the #{foo.value} 
> property, it (correctly, I assume) resolves to #{foo.bar}.  However, 
> if the component author then attempts to evaluate that value and 
> display it, manipulate it, etc.... then it will incorrectly evaluate 
> to (null) (there is no "bar" attribute for this component).  The 
> managed bean "foo" gets masked.

Hmm... I always thought that the VariableMapper for a ValueExpression is 
determined when the ValueExpression is created, not when when the 
ValueExpression is evaluated.  So, in the above example, when the 
ValueExpression for "#{foo.bar}" is created, it obtains a reference to 
the current  VariableMapper.  This VariableMapper would not include the 
compositeComponent's "foo" variable since that is not yet in scope.  
Even if the "#{foo.bar}" ValueExpression is later evaluated within the 
context of a composite component, it still uses its original 
VariableMapper, and thus is not impacted by the presence of the "foo" 
variable in the VariableMapper used by the composite component.

In any case, seems like this will shortly be a moot point - I believe 
that Ed will be sending out an alternate suggestion soon.

Andy

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/jsr-314-open-mirror/attachments/20090415/1ffce3b4/attachment.html