Re: Started using Myfaces 1.1.5 and every page is broken (duplicate ID in the faces tree Component)

[Werner Punz <we...@gmail.com>]

SiSi'mon schrieb:
> I am not sure what a session scoped component binding is.
> 
> do you mean a session scoped backing bean?  We are using Spring IOC to
> manage the backing beans and only have one that is session scoped.
> 
> thanks
> 
> Si'mon
> 
> 

Well following, if you have referenced this bean into something like:

<component binding="#{sessionbeanbean.bindingattribute}" /> and this 
bean is session scoped or even worse application scoped in spring then 
you run into this problem.


You can however since you use spring anyway and if you do not want to 
omit the session scope of your bean make the binding request scoped 
nevertheless.

Spring 2 has the aop:scoped proxy mechanism, which you can use to wrap a 
request scoped proxy once the session scoped bean references your 
binding object around it.

Which means a contstruct like that:

<component 
binding="#{sessionbeanbean.componentbindingholder.bindingattribute}" />
can work even if the bean is session scoped if the 
componentbindingholder is request scoped and has the aop:proxy construct 
around it.
(Sorry for going so deeply into spring)

what this means is following:


<bean id="componentbindingholder" scope="request">
    <aop:scoped-proxy />
</bean>

<bean id="sessionbean" scope="session" class="....">
   	<property name="componentbindingholder"
			ref="componentbindingholder" />

</bean>

what happens now is
that both beans are ioc glued together but, the contents of the 
componentbindingholder is dropped at every request, while its proxy 
shell stays the same the entire session.

Sorry for digging in so deep into spring, but this stuff is pure genious 
and definitely a good way to avoid the session scoped component binding 
problem. (It is a must have if you start to work with conversation based 
frameworks)


Werner