Package org.springframework.webflow.execution

Interface FlowExecutionListener

All Known Implementing Classes:
FlowExecutionListenerAdapter, FlowFacesContextLifecycleListener, HibernateFlowExecutionListener, JpaFlowExecutionListener, SecurityFlowExecutionListener
public interface FlowExecutionListener
Interface to be implemented by objects that wish to listen and respond to the lifecycle of flow executions.

An 'observer' that is very aspect like, allowing you to insert 'cross cutting' behavior at well-defined points within one or more well-defined flow execution lifecycles.

For example, one custom listener may apply security checks at the flow execution level, preventing a flow from starting or a state from entering if the current user does not have the necessary permissions. Another listener may track flow execution navigation history to support bread crumbs. Another may perform auditing, or setup and tear down connections to a transactional resource.

Note that flow execution listeners are registered with a flow execution when that execution is created by a factory or restored by a FlowExecutionRepository. Typically a listener will not be registered with a flow execution at runtime, when the flow execution is already active.

Author:
Keith Donald, Erwin Vervaet, Scott Andrews
See Also:

  • Method Details

    • requestSubmitted

      default void requestSubmitted(RequestContext context)
      Called when any client request is submitted to manipulate this flow execution. This call happens before request processing.
      Parameters:
      context - the current flow request context

    • requestProcessed

      default void requestProcessed(RequestContext context)
      Called when a client request has completed processing.
      Parameters:
      context - the source of the event

    • sessionCreating

      default void sessionCreating(RequestContext context, FlowDefinition definition)
      Called to indicate a new flow definition session is about to be created. Called before the session is created. An exception may be thrown from this method to veto the start operation. Any type of runtime exception can be used for this purpose.
      Parameters:
      context - the current flow request context
      definition - the flow for which a new session is starting

    • sessionStarting

      default void sessionStarting(RequestContext context, FlowSession session, MutableAttributeMap<?> input)
      Called after a new flow session has been created but before it starts. Useful for setting arbitrary attributes in the session before the flow starts.
      Parameters:
      context - the current flow request context
      session - the session that was created
      input - a mutable input map - attributes placed in this map are eligible for input mapping by the flow definition at startup

    • sessionStarted

      default void sessionStarted(RequestContext context, FlowSession session)
      Called after a new flow session has started. At this point the flow's start state has been entered and any other startup behaviors have been executed.
      Parameters:
      context - the current flow request context
      session - the session that was started

    • eventSignaled

      default void eventSignaled(RequestContext context, Event event)
      Called when an event is signaled in the current state, but prior to any state transition.
      Parameters:
      context - the current flow request context
      event - the event that occurred

    • transitionExecuting

      default void transitionExecuting(RequestContext context, TransitionDefinition transition)
      Called when a transition is matched but before the transition occurs.
      Parameters:
      context - the current flow request context
      transition - the proposed transition

    • stateEntering

      default void stateEntering(RequestContext context, StateDefinition state) throws EnterStateVetoException
      Called when a state transitions, after the transition is matched but before the transition occurs.
      Parameters:
      context - the current flow request context
      state - the proposed state to transition to
      Throws:
      EnterStateVetoException - when entering the state is not allowed

    • stateEntered

      default void stateEntered(RequestContext context, StateDefinition previousState, StateDefinition state)
      Called when a state transitions, after the transition occurred.
      Parameters:
      context - the current flow request context
      previousState - from state of the transition
      state - to state of the transition

    • viewRendering

      default void viewRendering(RequestContext context, View view, StateDefinition viewState)
      Called when a view is about to render in a view-state, before any render actions are executed.
      Parameters:
      context - the current flow request context
      view - the view that is about to render
      viewState - the current view state

    • viewRendered

      default void viewRendered(RequestContext context, View view, StateDefinition viewState)
      Called after a view has completed rendering.
      Parameters:
      context - the current flow request context
      view - the view that rendered
      viewState - the current view state

    • paused

      default void paused(RequestContext context)
      Called when a flow execution is paused, for instance when it is waiting for user input (after event processing).
      Parameters:
      context - the current flow request context

    • resuming

      default void resuming(RequestContext context)
      Called after a flow execution is successfully reactivated after pause (but before event processing).
      Parameters:
      context - the current flow request context

    • sessionEnding

      default void sessionEnding(RequestContext context, FlowSession session, String outcome, MutableAttributeMap<?> output)
      Called when the active flow execution session has been asked to end but before it has ended.
      Parameters:
      context - the current flow request context
      session - the current active session that is ending
      outcome - the outcome reached by the ending session, generally the id of the terminating end-state
      output - the flow output produced by the ending session, this map may be modified by this listener to affect the output returned

    • sessionEnded

      default void sessionEnded(RequestContext context, FlowSession session, String outcome, AttributeMap<?> output)
      Called when a flow execution session ends. If the ended session was the root session of the flow execution, the entire flow execution also ends.
      Parameters:
      context - the current flow request context
      session - ending flow session
      outcome - the outcome reached by the ended session, generally the id of the terminating end-state
      output - the flow output returned by the ending session

    • exceptionThrown

      default void exceptionThrown(RequestContext context, FlowExecutionException exception)
      Called when an exception is thrown during a flow execution, before the exception is handled by any registered handler.
      Parameters:
      context - the current flow request context
      exception - the exception that occurred