I posted this question
http://seamframework.org/Community/221CR1EntityQueryBug but got no response(never got). So I thought maybe can get some help here.
I generated UserList.java(EntityQuery class) and UserList.xthml using "seam generate-ui" command, based on entity class: User.java.
The problem is: when
testing the search function in UserList.xhtml, I got the following error:
WARN [org.jboss.seam.Component] Cannot create Seam component, scope is not active: entityManager(CONVERSATION)
I searched deeper into code and found this seems something inevitable.
After 'Search's clicked, UserList.xhtml will go into
JSF restore view phase. Since the page uses 'userList' component, the component needs to be created.
When creating 'userList' component, it needs to call component's @Create method, which is validate(). In EntityQuery's validate method, it checks for entity manager, which is in conversation scope.
The problem is, at that time, conversation context has not been created for the
thread. Thus entity manager cannot be created. Exception throws.
An interesting thing is, the conversation context is created just after that, in handleAfterPhase of restore view phase:
SeamPhaseListener.java:
FacesLifecycle.java:
Have I missed anything? Or it's a bug?