org.springframework.webflow.execution.FlowExecutionContext Maven / Gradle / Ivy
/*
* 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.execution;
import org.springframework.webflow.core.collection.AttributeMap;
import org.springframework.webflow.core.collection.MutableAttributeMap;
import org.springframework.webflow.definition.FlowDefinition;
/**
* Provides contextual information about a flow execution. A flow execution is an runnable instance of a
* {@link FlowDefinition}. It is the central Spring Web Flow construct for carrying out a conversation with a client.
* This immutable interface provides access to runtime information about the conversation, such as it's
* {@link #isActive() status} and {@link #getActiveSession() current state}.
*
* An object implementing this interface is also traversable from a execution request context (see
* {@link org.springframework.webflow.execution.RequestContext#getFlowExecutionContext()}).
*
* This interface provides information that may span more than one request in a thread safe manner. The
* {@link RequestContext} interface defines a request specific control interface for manipulating exactly one
* flow execution locally from exactly one request.
*
* @see FlowDefinition
* @see FlowSession
* @see RequestContext
*
* @author Keith Donald
* @author Erwin Vervaet
*/
public interface FlowExecutionContext {
/**
* Returns the key assigned to this flow execution. The flow execution key is the flow execution's persistent
* identity.
* @return the flow execution key; may be null if a key has not yet been assigned.
*/
public FlowExecutionKey getKey();
/**
* Returns the root flow definition associated with this executing flow.
*
* A call to this method always returns the same flow definition -- the top-level "root" -- no matter what flow may
* actually be active (for example, if subflows have been spawned).
* @return the root flow definition
*/
public FlowDefinition getDefinition();
/**
* Returns a flag indicating if this execution has been started. A flow execution that has started and is active is
* currently in progress. A flow execution that has started and is not active has ended.
* @see #isActive()
* @return true if started, false if not started
*/
public boolean hasStarted();
/**
* Is the flow execution active? A flow execution is active once it has an {@link #getActiveSession() active
* session} and remains active until it has ended.
* @return true if active, false if the flow execution has terminated or has not yet been started
*/
public boolean isActive();
/**
* Returns a flag indicating if this execution has ended. A flow execution that has ended has been started but is no
* longer active.
* @see #hasStarted()
* @see #isActive()
* @return true if ended, false if not started or still active
*/
public boolean hasEnded();
/**
* Returns the outcome reached by this execution, or null if this execution has not yet ended.
* @return the outcome, or null if this execution has not yet ended
*/
public FlowExecutionOutcome getOutcome();
/**
* Returns the active flow session of this flow execution. The active flow session is the currently executing
* session. It may be the "root flow" session, or it may be a subflow session if this flow execution has spawned a
* subflow.
* @return the active flow session
* @throws IllegalStateException if this flow execution is not active
* @see #isActive()
*/
public FlowSession getActiveSession() throws IllegalStateException;
/**
* Returns a mutable map for data held in "flash scope". Attributes in this map are cleared out on the next view
* rendering. Flash attributes survive flow execution refresh operations.
* @return flash scope
*/
public MutableAttributeMap