I am trying to implement the Google image labeler using Seam (2.2.0 GA/JBoss: 5.1.0 GA).

• The entity gameSession (see below) holds the context for a game session.


• The stateless component gameSessionBean (see below) manages the gameSession.


• The workflow is defined as jbpm business process (see below).

Unfortunately, I am losing the (game) business process variable while executing the business process.

1. The process starts with the node start round and I can access #{gameSessionBean.startRound()} to start the round. Everyting seems to be alright according to the Eclipse debugger.


2. The process forks to two players. Both need to pass their own task node ( label image), that can again access gameSessionBean without problems. Having labeled the image, the processing path joins again.


3. However, in the transition end round after the jbpm join node, I cannot access gameSessionBean anymore. It is NULLed out. Why?

I tried solutions that are proposed in the Web:

* @BypassInterceptors for the entity
* Using explicit @Out(scope = ScopeType.BUSINESS_PROCESS, required = false)

What can I do to have a variable that is permanently scoped to the instance of a business process? Even the APPLICATION scope is not available during the execution of #{gameSessionBean.endRound()}. Is this a bug???

This post may be related to:

• http://seamframework.org/Community/OutjectedScopeTypeBUSINESSPROCESSJBPMVariableScopeTaskOrProcess


• http://lists.jboss.org/pipermail/jboss-user/2007-June/062449.html

Code snippets:

@Entity
@Name("gameSession")
@Scope(ScopeType.BUSINESS_PROCESS)
public class GameSession implements Serializable {
        @GeneratedValue
        @Id
        private Integer id;
[...]
}

@Name("gameSessionBean")
@Scope(ScopeType.STATELESS)
public class GameSessionBean implements Serializable {

        @In(create = true)
        @Out
        public GameSession gameSession;

        @CreateProcess(definition="")
        private String startBusinessProcess(String string) {
              return "game"
        }

        @EndTask
        @StartTask
        public String startTask() {             
                return "game";
        }
}

<?xml version="1.0" encoding="UTF-8"?>

<process-definition name="gameImageLabeler">
        <start-state name="start">
                <transition to="start round" name="start game"></transition>
        </start-state>

        <task-node name="[p1] label image">
                <task name="labelImage" description="Player A">
                        <assignment actor-id="#{gameSessionBean.getPlayerId(0)}" />
                </task>
                <transition to="join1" name="[p1] wait for p2"></transition>
        </task-node>

        <task-node name="[p2] label image">
                <task name="labelImage" description="Player B">
                        <assignment actor-id="#{gameSessionBean.getPlayerId(1)}" />
                </task>
                <transition to="join1" name="[p2] wait for p1"></transition>
        </task-node>

        <fork name="fork1">
                <transition to="[p1] label image" name="[p1] label image"></transition>
                <transition to="[p2] label image" name="[p2] label image">
                        <action></action>
                </transition>
        </fork>

        <join name="join1">
                <transition to="new or end" name="end round">
                        <action name="end round" expression="#{gameSessionBean.endRound()}"></action>
                </transition>
        </join>

        <node name="start round">
                <transition to="fork1" name="init round">
                        <action name="init round" expression="#{gameSessionBean.startRound()}"></action>
                </transition>
        </node>

        <decision name="new or end"
                expression="#{(gameSessionBean.hasNextRound()) ? 'to init round' : 'end game session'}">
                <transition to="done" name="end game session"></transition>
                <transition to="start round" name="to init round"></transition>
        </decision>

        <end-state name="done" />
</process-definition>