On Tue, Jul 28, 2009 at 9:00 AM, Pete Muir <pmuir@redhat.com> wrote:

Hi all,

I would like to propose adding ExpressionFactory to the list of classes required to support the decorator pattern. This is to aid integration with CDI (JSR-299) implementations, which are require a callback when EL expression evaluation completes; the necessary hook into EL is via the ExpressionFactory. Adding ExpressionFactory to this list would make implemetors have to jump through fewer hoops to obtain the callback [1].

I propose this change to the MR so it can be used in the EE6 platform, the target for JSR-299.

Changes to spec required
-----------------------------------

* Add ExpressionFactory to the list of classes required to support the decorator pattern
* Add ExpressionFactoryWrapper class to support the decorator pattern

Changes to implementation required
--------------------------------------------------

* Add support for exposing and using wrapped ExpressionFactory

Impact on users and frameworks
--------------------------------------------

Users can now:

* call application.setExpressionFactory(new WebBeansExpressionFactory(application.getExpressionFactory());
* configure a wrapping expression factory in faces-config.xml
<application>
<expressionFactory>org.jboss.webbeans.el.WebBeansExpressionFactory</expressionFactory>
</application>

[1] Currently this is possible by wrapping the application via the application factory and overriding the getExpressionFactory method