/*
* Copyright 2004-2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.webflow.engine;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.execution.Event;
import org.springframework.webflow.execution.FlowExecutionContext;
import org.springframework.webflow.execution.FlowExecutionException;
import org.springframework.webflow.execution.FlowExecutionKey;
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.
* Primarily used internally by the various flow artifacts when they are invoked.
* <p>
* This interface acts as a facade for core definition constructs such as the central <code>Flow</code> and
* <code>State</code> classes, abstracting away details about the runtime execution machine.
* <p>
* Note this type is not the same as the {@link FlowExecutionContext}. Objects of this type are <i>request specific</i>:
* they provide a control interface for manipulating exactly one flow execution locally from exactly one request. A
* <code>FlowExecutionContext</code> provides information about a single flow execution (conversation), and it's scope
* is not local to a specific request (or thread).
*
* @see org.springframework.webflow.engine.Flow
* @see org.springframework.webflow.engine.State
* @see org.springframework.webflow.execution.FlowExecution
* @see FlowExecutionContext
*
* @author Keith Donald
* @author Erwin Vervaet
*/
public interface RequestControlContext extends RequestContext {
/**
* Record the current state that has entered in the executing flow. This method will be called as part of entering a
* new state by the State type itself.
* @param state the current state
* @see State#enter(RequestControlContext)
*/
public void setCurrentState(State state);
/**
* Assign the ongoing flow execution its flow execution key. This method will be called before a state is about to
* render a view and pause the flow execution.
*/
public FlowExecutionKey assignFlowExecutionKey();
/**
* Sets the current view.
* @param view the current view, or null to mark the current view as <code>null</code>
*/
public void setCurrentView(View view);
/**
* Called when the current view is about to be rendered in the current view state.
* @param view the view to be rendered
*/
public void viewRendering(View view);
/**
* Called when the current view has completed rendering in the current view state.
* @param view the view that rendered
*/
public void viewRendered(View view);
/**
* Signals the occurrence of an event in the current state of this flow execution request context. This method
* should be called by clients that report internal event occurrences, such as action states. The
* <code>onEvent()</code> method of the flow involved in the flow execution will be called.
* @param event the event that occurred
* @return a boolean indicating if handling this event caused the current state to exit and a new state to enter
* @throws FlowExecutionException if an exception was thrown within a state of the flow during execution of this
* signalEvent operation
* @see Flow#handleEvent(RequestControlContext)
*/
public boolean handleEvent(Event event) throws FlowExecutionException;
/**
* Execute this transition out of the current source state. Allows for privileged execution of an arbitrary
* transition.
* @param transition the transition
* @see Transition#execute(State, RequestControlContext)
*/
public boolean execute(Transition transition);
/**
* Record the transition executing in the flow. This method will be called as part of executing a transition from
* one state to another.
* @param transition the transition being executed
* @see Transition#execute(State, RequestControlContext)
*/
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.
* <p>
* This will start a new flow session in the current flow execution, which is already active.
* @param flow the flow to start, its <code>start()</code> method will be called
* @param input initial contents of the newly created flow session (may be <code>null</code>, e.g. empty)
* @throws FlowExecutionException if an exception was thrown within a state of the flow during execution of this
* start operation
* @see Flow#start(RequestControlContext, MutableAttributeMap)
*/
public void start(Flow flow, MutableAttributeMap<?> input) throws FlowExecutionException;
/**
* End the active flow session of the current flow execution. This method should be called by clients that terminate
* flows, such as end states. The <code>end()</code> method of the flow involved in the flow execution will be
* called.
* @param outcome the logical outcome the ending session should return
* @param output output the ending session should return
* @throws IllegalStateException when the flow execution is not active
* @see Flow#end(RequestControlContext, String, MutableAttributeMap)
*/
public void endActiveFlowSession(String outcome, MutableAttributeMap<Object> output) throws IllegalStateException;
/**
* Returns true if the 'redirect on pause' flow execution attribute is set to true, false otherwise.
* @return true or false
*/
public boolean getRedirectOnPause();
/**
* Returns the value of the 'redirect in same state' flow execution attribute if set or otherwise it falls back on
* the value returned by {@link #getRedirectOnPause()}.
* @return true or false
*/
public boolean getRedirectInSameState();
/**
* Returns true if the flow current flow execution was launched in embedded page mode. When a flow is embedded on a
* page it can make different assumptions with regards to whether redirect after post is necessary.
*/
public boolean getEmbeddedMode();
}