org.springframework.webflow.engine.RequestControlContext Maven / Gradle / Ivy
/*
* Copyright 2004-2007 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.FlowSession;
import org.springframework.webflow.execution.RequestContext;
import org.springframework.webflow.execution.ViewSelection;
/**
* 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.
*
* This interface acts as a facade for core definition constructs such as the central Flow and
* State classes, abstracting away details about the runtime execution machine defined in the
* {@link org.springframework.webflow.engine.impl execution engine implementation} package.
*
* Note this type is not the same as the {@link FlowExecutionContext}. Objects of this type are request specific:
* they provide a control interface for manipulating exactly one flow execution locally from exactly one request. A
* FlowExecutionContext 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 last event signaled in the executing flow. This method will be called as part of signaling an event in
* a flow to indicate the 'lastEvent' that was signaled.
* @param lastEvent the last event signaled
* @see Flow#onEvent(RequestControlContext)
*/
public void setLastEvent(Event lastEvent);
/**
* Record the last transition that executed in the executing flow. This method will be called as part of executing a
* transition from one state to another.
* @param lastTransition the last transition that executed
* @see Transition#execute(State, RequestControlContext)
*/
public void setLastTransition(Transition lastTransition);
/**
* 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);
/**
* 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.
*
* This will start a new flow session in the current flow execution, which is already active.
* @param flow the flow to start, its start() method will be called
* @param input initial contents of the newly created flow session (may be null, e.g. empty)
* @return the selected starting view, which returns control to the client and requests that a view be rendered with
* model data
* @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 ViewSelection start(Flow flow, MutableAttributeMap input) throws FlowExecutionException;
/**
* Signals the occurence of an event in the current state of this flow execution request context. This method should
* be called by clients that report internal event occurences, such as action states. The onEvent()
* method of the flow involved in the flow execution will be called.
* @param event the event that occured
* @return the next selected view, which returns control to the client and requests that a view be rendered with
* model data
* @throws FlowExecutionException if an exception was thrown within a state of the flow during execution of this
* signalEvent operation
* @see Flow#onEvent(RequestControlContext)
*/
public ViewSelection signalEvent(Event event) 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 end() method of the flow involved in the flow execution will be
* called.
* @param output output produced by the session that is eligible for mapping by a resuming parent flow
* @return the ended session
* @throws IllegalStateException when the flow execution is not active
* @see Flow#end(RequestControlContext, MutableAttributeMap)
*/
public FlowSession endActiveFlowSession(MutableAttributeMap output) throws IllegalStateException;
/**
* Execute this transition out of the current source state. Allows for privileged execution of an arbitrary
* transition.
* @param transition the transition
* @return a new view selection
* @see Transition#execute(State, RequestControlContext)
*/
public ViewSelection execute(Transition transition);
}