[webbeans-dev] How does JSF deal with managed beans when Web Beans/299 is present?

[Pete Muir]

Hi

I realized we have a potential conflict between JSF and 299 to do with  
EE defined managed beans, which we need to address. Imagine the  
following scenario: A managed bean is defined using @ManagedBean in a  
war in which both JSF and Web Beans is enabled. In this case both JSF  
and Web Beans will attempt to manage the bean, however according to  
the latest note sent by Roberto Chinnici to the EE expert group, if  
299 is present, 299 should manage the bean. We need to address how to  
deal with this for both Web Beans and Mojarra.

Some points to consider:

* 90% of the time there is no problem, the Web Beans ELResolver is  
installed before the JSF ManagedBeanELResolver. However the corner  
case of an eager instantiated, application scoped managed bean with a  
post construct lifecycle callback will cause us a problem. There may  
also be other corner cases we haven't considered. For this reason, I  
think we should consider being able to explicitly disable JSF managed  
beans
* this doesn't affect other specs which may use managed beans as much,
   (a) as Mojarra works in other containers than GlassFish, such as  
Tomcat, where Web Beans may not be present
   (b)  299 specifically states that JSF should use an ELResolver as  
it's integration point (other specs integration point is programatic  
and so can use an SPI if or similar - Ken's suggestion from our latest  
meeting for those who were there)
* Mojarra will need to continue to provide xml-defined managed beans  
when Web Beans/299 is present.

My suggested solution is to simply have a switch in Mojarra we can use  
to "turn off" annotation-defined managed beans support (either  
automatic via detection of WEB-INF/beans.xml or manual via web.xml or  
programatically).

Pete

On 31 Jul 2009, at 20:11, Barbara Louis wrote:

> - How we deal with jsf managed beans when 299 is present?
> - 299 requires managed beans
> - JSF RI will need to make the change - the ques to ask is: should  
> jsf manage the managed beans or should I let the EE container to  
> manage it for me?
> - Pete will send an email on webbeans dev mailing list on this topic  
> and include Mojarra mailing list (webtier at glassfish.dev.java.net)