view rendering listener hooks

spring-webflow/src/main/java/org/springframework/webflow/engine/RequestControlContext.java

@@ -22,6 +22,7 @@ import org.springframework.webflow.execution.FlowExecutionException;
 import org.springframework.webflow.execution.FlowExecutionKey;
 import org.springframework.webflow.execution.FlowSession;
 import org.springframework.webflow.execution.RequestContext;
+import org.springframework.webflow.execution.View;
 
 /**
  * Mutable control interface used to manipulate an ongoing flow execution in the context of one client request.
@@ -60,19 +61,16 @@ public interface RequestControlContext extends RequestContext {
 	public FlowExecutionKey assignFlowExecutionKey();
 
 	/**
-	 * Update the current flow execution snapshot to save the current state.
+	 * Called when a view is about to be rendered in the current view state.
+	 * @param view the view to be rendered
 	 */
-	public void updateCurrentFlowExecutionSnapshot();
+	public void viewRendering(View view);
 
 	/**
-	 * Remove the current flow execution snapshot to invalidate the current state.
+	 * Called when a view has completed rendering in the current view state.
+	 * @param view the view that rendered
 	 */
-	public void removeCurrentFlowExecutionSnapshot();
-
-	/**
-	 * Remove all flow execution snapshots associated with the ongoing conversation. Invalidates previous states.
-	 */
-	public void removeAllFlowExecutionSnapshots();
+	public void viewRendered(View view);
 
 	/**
 	 * Signals the occurrence of an event in the current state of this flow execution request context. This method
@@ -102,6 +100,21 @@ public interface RequestControlContext extends RequestContext {
 	 */
 	public void setCurrentTransition(Transition transition);
 
+	/**
+	 * Update the current flow execution snapshot to save the current state.
+	 */
+	public void updateCurrentFlowExecutionSnapshot();
+
+	/**
+	 * Remove the current flow execution snapshot to invalidate the current state.
+	 */
+	public void removeCurrentFlowExecutionSnapshot();
+
+	/**
+	 * Remove all flow execution snapshots associated with the ongoing conversation. Invalidates previous states.
+	 */
+	public void removeAllFlowExecutionSnapshots();
+
 	/**
 	 * Spawn a new flow session and activate it in the currently executing flow. Also transitions the spawned flow to
 	 * its start state. This method should be called by clients that wish to spawn new flows, such as subflow states.

spring-webflow/src/main/java/org/springframework/webflow/engine/ViewState.java

@@ -263,6 +263,7 @@ public class ViewState extends TransitionableState {
 			logger.debug("  Flash scope = " + context.getFlashScope());
 			logger.debug("  Messages = " + context.getMessageContext());
 		}
+		context.viewRendering(view);
 		renderActionList.execute(context);
 		try {
 			view.render();
@@ -271,6 +272,7 @@ public class ViewState extends TransitionableState {
 		}
 		context.getMessageContext().clearMessages();
 		context.getFlashScope().clear();
+		context.viewRendered(view);
 	}
 
 	private void restoreVariables(RequestContext context) {

spring-webflow/src/main/java/org/springframework/webflow/engine/impl/FlowExecutionImpl.java

@@ -49,6 +49,7 @@ import org.springframework.webflow.execution.FlowExecutionListener;
 import org.springframework.webflow.execution.FlowSession;
 import org.springframework.webflow.execution.RequestContext;
 import org.springframework.webflow.execution.RequestContextHolder;
+import org.springframework.webflow.execution.View;
 
 /**
  * Default implementation of FlowExecution that uses a stack-based data structure to manage spawned flow sessions. This
@@ -368,6 +369,14 @@ public class FlowExecutionImpl implements FlowExecution, Externalizable {
 		listeners.fireStateEntered(context, previousState);
 	}
 
+	public void viewRendering(View view, RequestContext context) {
+		listeners.fireViewRendering(context, view);
+	}
+
+	public void viewRendered(View view, RequestContext context) {
+		listeners.fireViewRendered(context, view);
+	}
+
 	boolean handleEvent(Event event, RequestControlContext context) {
 		listeners.fireEventSignaled(context, event);
 		return getActiveSessionInternal().getFlow().handleEvent(context);
@@ -637,4 +646,5 @@ public class FlowExecutionImpl implements FlowExecution, Externalizable {
 		State currentState = (State) session.getState();
 		return currentState;
 	}
+
 }

spring-webflow/src/main/java/org/springframework/webflow/engine/impl/FlowExecutionListeners.java

@@ -25,6 +25,7 @@ import org.springframework.webflow.execution.FlowExecutionException;
 import org.springframework.webflow.execution.FlowExecutionListener;
 import org.springframework.webflow.execution.FlowSession;
 import org.springframework.webflow.execution.RequestContext;
+import org.springframework.webflow.execution.View;
 
 /**
  * A helper that aids in publishing events to an array of <code>FlowExecutionListener</code> objects.
@@ -153,6 +154,24 @@ class FlowExecutionListeners {
 		}
 	}
 
+	/**
+	 * Notify all interested listeners that a flow execution view is rendering.
+	 */
+	public void fireViewRendering(RequestContext context, View view) {
+		for (int i = 0; i < listeners.length; i++) {
+			listeners[i].viewRendering(context, view, context.getCurrentState());
+		}
+	}
+
+	/**
+	 * Notify all interested listeners that a flow execution has rendered.
+	 */
+	public void fireViewRendered(RequestContext context, View view) {
+		for (int i = 0; i < listeners.length; i++) {
+			listeners[i].viewRendered(context, view, context.getCurrentState());
+		}
+	}
+
 	/**
 	 * Notify all interested listeners that a transition is being entered in the flow execution.
 	 */

spring-webflow/src/main/java/org/springframework/webflow/engine/impl/RequestControlContextImpl.java

@@ -35,6 +35,7 @@ import org.springframework.webflow.execution.FlowExecutionContext;
 import org.springframework.webflow.execution.FlowExecutionException;
 import org.springframework.webflow.execution.FlowExecutionKey;
 import org.springframework.webflow.execution.FlowSession;
+import org.springframework.webflow.execution.View;
 
 /**
  * Default request control context implementation used internally by the web flow system. This class is closely coupled
@@ -187,14 +188,31 @@ class RequestControlContextImpl implements RequestControlContext {
 		flowExecution.setCurrentState(state, this);
 	}
 
-	public void setCurrentTransition(Transition transition) {
-		this.currentTransition = transition;
-	}
-
 	public FlowExecutionKey assignFlowExecutionKey() {
 		return flowExecution.assignKey();
 	}
 
+	public void viewRendering(View view) {
+		flowExecution.viewRendering(view, this);
+	}
+
+	public void viewRendered(View view) {
+		flowExecution.viewRendered(view, this);
+	}
+
+	public boolean handleEvent(Event event) throws FlowExecutionException {
+		this.currentEvent = event;
+		return flowExecution.handleEvent(event, this);
+	}
+
+	public boolean execute(Transition transition) {
+		return flowExecution.execute(transition, this);
+	}
+
+	public void setCurrentTransition(Transition transition) {
+		this.currentTransition = transition;
+	}
+
 	public void updateCurrentFlowExecutionSnapshot() {
 		flowExecution.updateCurrentFlowExecutionSnapshot();
 	}
@@ -207,20 +225,6 @@ class RequestControlContextImpl implements RequestControlContext {
 		flowExecution.removeAllFlowExecutionSnapshots();
 	}
 
-	public boolean getAlwaysRedirectOnPause() {
-		Boolean redirectOnPause = flowExecution.getAttributes().getBoolean("alwaysRedirectOnPause");
-		return redirectOnPause != null ? redirectOnPause.booleanValue() : false;
-	}
-
-	public boolean handleEvent(Event event) throws FlowExecutionException {
-		this.currentEvent = event;
-		return flowExecution.handleEvent(event, this);
-	}
-
-	public boolean execute(Transition transition) {
-		return flowExecution.execute(transition, this);
-	}
-
 	public void start(Flow flow, MutableAttributeMap input) throws FlowExecutionException {
 		flowExecution.start(flow, input, this);
 	}
@@ -229,6 +233,11 @@ class RequestControlContextImpl implements RequestControlContext {
 		return flowExecution.endActiveFlowSession(output, this);
 	}
 
+	public boolean getAlwaysRedirectOnPause() {
+		Boolean redirectOnPause = flowExecution.getAttributes().getBoolean("alwaysRedirectOnPause");
+		return redirectOnPause != null ? redirectOnPause.booleanValue() : false;
+	}
+
 	public String toString() {
 		return new ToStringCreator(this).append("externalContext", externalContext)
 				.append("requestScope", requestScope).append("attributes", attributes).append("flowExecution",

spring-webflow/src/main/java/org/springframework/webflow/execution/FlowExecutionListener.java

@@ -54,7 +54,7 @@ public interface FlowExecutionListener {
 	/**
 	 * Called when any client request is submitted to manipulate this flow execution. This call happens before request
 	 * processing.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 */
 	public void requestSubmitted(RequestContext context);
 
@@ -68,7 +68,7 @@ public interface FlowExecutionListener {
 	 * 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.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param definition the flow for which a new session is starting
 	 */
 	public void sessionCreating(RequestContext context, FlowDefinition definition);
@@ -76,7 +76,7 @@ public interface FlowExecutionListener {
 	/**
 	 * 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.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param session the session that was created
 	 * @param input a mutable input map - attributes placed in this map are eligible for input mapping by the flow
 	 * definition at startup
@@ -86,36 +86,44 @@ public interface FlowExecutionListener {
 	/**
 	 * 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.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param session the session that was started
 	 */
 	public void sessionStarted(RequestContext context, FlowSession session);
 
 	/**
 	 * Called when an event is signaled in the current state, but prior to any state transition.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param event the event that occurred
 	 */
 	public void eventSignaled(RequestContext context, Event event);
 
 	/**
 	 * Called when a transition is matched but before the transition occurs.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param transition the proposed transition
 	 */
 	public void transitionExecuting(RequestContext context, TransitionDefinition transition);
 
 	/**
 	 * Called when a state transitions, after the transition is matched but before the transition occurs.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param state the proposed state to transition to
 	 * @throws EnterStateVetoException when entering the state is not allowed
 	 */
 	public void stateEntering(RequestContext context, StateDefinition state) throws EnterStateVetoException;
 
+	/**
+	 * Called when a state transitions, after the transition occurred.
+	 * @param context the current flow request context
+	 * @param previousState <i>from</i> state of the transition
+	 * @param state <i>to</i> state of the transition
+	 */
+	public void stateEntered(RequestContext context, StateDefinition previousState, StateDefinition state);
+
 	/**
 	 * Called when a view is about to render in a view-state, before any render actions are executed.
-	 * @param context the current request context
+	 * @param context the current flow request context
 	 * @param view the view that is about to render
 	 * @param viewState the current view state
 	 */
@@ -123,35 +131,27 @@ public interface FlowExecutionListener {
 
 	/**
 	 * Called after a view has completed rendering.
-	 * @param context the current request context
+	 * @param context the current flow request context
 	 * @param view the view that rendered
 	 * @param viewState the current view state
 	 */
 	public void viewRendered(RequestContext context, View view, StateDefinition viewState);
 
-	/**
-	 * Called when a state transitions, after the transition occurred.
-	 * @param context the source of the event
-	 * @param previousState <i>from</i> state of the transition
-	 * @param state <i>to</i> state of the transition
-	 */
-	public void stateEntered(RequestContext context, StateDefinition previousState, StateDefinition state);
-
 	/**
 	 * Called when a flow execution is paused, for instance when it is waiting for user input (after event processing).
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 */
 	public void paused(RequestContext context);
 
 	/**
 	 * Called after a flow execution is successfully reactivated after pause (but before event processing).
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 */
 	public void resuming(RequestContext context);
 
 	/**
 	 * Called when the active flow execution session has been asked to end but before it has ended.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param session the current active session that is ending
 	 * @param output the flow output produced by the ending session, this map may be modified by this listener to affect
 	 * the output returned
@@ -161,7 +161,7 @@ public interface FlowExecutionListener {
 	/**
 	 * 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.
-	 * @param context the source of the event
+	 * @param context the current flow request context
 	 * @param session ending flow session
 	 * @param output final, unmodifiable output returned by the ended session
 	 */
@@ -170,7 +170,7 @@ public interface FlowExecutionListener {
 	/**
 	 * Called when an exception is thrown during a flow execution, before the exception is handled by any registered
 	 * {@link FlowExecutionExceptionHandler handler}.
-	 * @param context the source of the exception
+	 * @param context the current flow request context
 	 * @param exception the exception that occurred
 	 */
 	public void exceptionThrown(RequestContext context, FlowExecutionException exception);

spring-webflow/src/main/java/org/springframework/webflow/test/MockRequestControlContext.java

@@ -25,6 +25,7 @@ import org.springframework.webflow.execution.Event;
 import org.springframework.webflow.execution.FlowExecutionContext;
 import org.springframework.webflow.execution.FlowExecutionKey;
 import org.springframework.webflow.execution.FlowSession;
+import org.springframework.webflow.execution.View;
 
 /**
  * Mock implementation of the {@link RequestControlContext} interface to facilitate standalone Flow and State unit
@@ -76,6 +77,21 @@ public class MockRequestControlContext extends MockRequestContext implements Req
 		return key;
 	}
 
+	public void viewRendering(View view) {
+	}
+
+	public void viewRendered(View view) {
+	}
+
+	public boolean handleEvent(Event event) {
+		setCurrentEvent(event);
+		return ((Flow) getActiveFlow()).handleEvent(this);
+	}
+
+	public boolean execute(Transition transition) {
+		return transition.execute((TransitionableState) getCurrentState(), this);
+	}
+
 	public void removeAllFlowExecutionSnapshots() {
 
 	}
@@ -88,15 +104,6 @@ public class MockRequestControlContext extends MockRequestContext implements Req
 
 	}
 
-	public boolean handleEvent(Event event) {
-		setCurrentEvent(event);
-		return ((Flow) getActiveFlow()).handleEvent(this);
-	}
-
-	public boolean execute(Transition transition) {
-		return transition.execute((TransitionableState) getCurrentState(), this);
-	}
-
 	public void start(Flow flow, MutableAttributeMap input) throws IllegalStateException {
 		MockFlowSession session = new MockFlowSession(flow, input);
 		if (getFlowExecutionContext().isActive()) {

spring-webflow/src/test/java/org/springframework/webflow/engine/model/builder/xml/XmlFlowModelBuilderTests.java

@@ -278,9 +278,19 @@ public class XmlFlowModelBuilderTests extends TestCase {
 		FlowExecutionImplFactory factory = new FlowExecutionImplFactory();
 		factory.setExecutionListenerLoader(new StaticFlowExecutionListenerLoader(new FlowExecutionListenerAdapter() {
 			public void viewRendering(RequestContext context, View view, StateDefinition viewState) {
-				BindingResult result = (BindingResult) context.getFlashScope().get(
-						"org.springframework.validation.BindingResult.formBean");
-				assertEquals(1, result.getErrorCount());
+				if (context.getCurrentEvent() != null && context.getCurrentEvent().getId().equals("submit")) {
+					BindingResult result = (BindingResult) context.getFlashScope().get(
+							"org.springframework.validation.BindingResult.formBean");
+					assertEquals(1, result.getErrorCount());
+				}
+			}
+
+			public void viewRendered(RequestContext context, View view, StateDefinition viewState) {
+				if (context.getCurrentEvent() != null && context.getCurrentEvent().getId().equals("submit")) {
+					BindingResult result = (BindingResult) context.getFlashScope().get(
+							"org.springframework.validation.BindingResult.formBean");
+					assertNull(result);
+				}
 			}
 		}));
 		FlowExecution execution = factory.createFlowExecution(flow);