problem with datamodel and a4j:commandLink

[hasc]

Hello,

i have the following problem width seam and a4j:
on one page the user can enter some parameters in a form and submit them by a a4j:commandButton. An @Entity is created and added to a List. This list is in return outjected (as @Datamodel or via getList(), i tried both), and a dataTable is reRendered.

everything works so far.

I added a a4j:commandLink in each row which executes a delete action. deleting works fine as long as the list contains more than one object.

the EL to delete the object looks like that:

#{tcmanager.deleteArea(ea)

But whenever the list contains only one object and it gets deleted, i get the following exception:

No ClassLoaders found for: de.axima.gmp.entity.EffectiveArea
java.lang.ClassNotFoundException: No ClassLoaders found for: de.axima.gmp.entity.EffectiveArea
 at org.jboss.mx.loading.LoadMgr3.beginLoadTask(LoadMgr3.java:212)
 at org.jboss.mx.loading.RepositoryClassLoader.loadClassImpl(RepositoryClassLoader.java:511)
 at org.jboss.mx.loading.RepositoryClassLoader.loadClass(RepositoryClassLoader.java:405)
 at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
 at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

for testing i changed the method and passed no paramter and simply deleted the object with index 0 out of the list:

#{tcmanager.deleteArea

i can delete all objects without errors.

Can someone give me a hint what the problem is or is it simply not supported to pass parameters in a a4j actionListener?

if thats the case it would be great if somone could explain me in short how to realize it in a different way.

thanks a lot and regards,
hasc

[alexsmirnov]

This is classloading problem, due to different modules in enterprise application.
You have EffectiveArea class in ejb jar, and it content not availible in a web application. At rendering time, Seam ( as usual, seam.jar is placed at EAR level, and have access to all modules ) parse EL expression and store type of parameter into ActionExpression instance. At a RESTORE_VIEW phase, web content can't load this class for de-serialisation of a component attribute.
You can store row number as a parameter for a link, or use any simple class ( String, Integer etc ) for a expression parameter, like :

#{tcmanager.deleteArea(ea.id)

[hasc]

ok thanks for your reply.

i understand your point. but it is strange since it works except in the case there' s only one instance in the List. So the ClassLoading Exception is only thrown in this case.