Module jakarta.faces
Package com.sun.faces.facelets.el

Class ContextualCompositeValueExpression

java.lang.Object
jakarta.el.Expression
jakarta.el.ValueExpression
com.sun.faces.facelets.el.ContextualCompositeValueExpression
All Implemented Interfaces:
Serializable
public final class ContextualCompositeValueExpression extends ValueExpression

This specialized ValueExpression enables the evaluation of composite component expressions. Instances of this expression will be created when TagAttributeImpl.getValueExpression(jakarta.faces.view.facelets.FaceletContext, Class) is invoked and the expression represents a composite component expression (i.e. #{cc.[properties]}).

It's important to note that these ValueExpressions are context sensitive in that they leverage the location in which they were referenced in order to push the proper composite component to the evaluation context prior to evaluating the expression itself.

Here's an example: 
 Using Page test.xhtml
 ---------------------------------
    <ez:comp1 greeting="Hello!" />


 comp1.xhtml
 ---------------------------------
 <composite:interface>
    <composite:attribute name="greeting" type="java.lang.String" required="true" />
 </composite:interface>
 <composite:implementation>
    <ez:nesting>
       <h:outputText value="#{cc.attrs.greetings}" />
    </ez:nesting>
 </composite:implementation>

 nesting.xhtml
 ---------------------------------
 <composite:interface />
 <composite:implementation>
    <composite:insertChildren>
 </composite:implementation>

In the above example, there will be two composite components available to the runtime: ez:comp1 and ez:nesting.

When <h:outputText value="#{cc.attrs.greeting}" />, prior to attempting to evaluate the expression, the Location object will be used to find the composite component that 'owns' the template in which the expression was defined in by comparing the path of the Location with the name and library of the Resource instance associated with each composite component. If a matching composite component is found, it will be made available to the EL by calling CompositeComponentStackManager.push(jakarta.faces.component.UIComponent).

See Also: