org.springframework.webflow.execution.FlowSession Maven / Gradle / Ivy
/*
* Copyright 2004-2008 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.MutableAttributeMap;
import org.springframework.webflow.definition.FlowDefinition;
import org.springframework.webflow.definition.StateDefinition;
/**
* A single, local instantiation of a {@link FlowDefinition flow definition} launched within an overall flow execution.
*
* This object maintains all instance state including session status within exactly one governing FlowExecution, as well
* as the current flow state. This object also acts as the local "flow scope" data model. Data in
* {@link #getScope() flow scope} lives for the life of this object and is cleaned up automatically when this object is
* destroyed. Destruction happens when this session enters an end state.
*
* Note that a flow session is in no way linked to an HTTP session. It just uses the familiar "session" naming
* convention to denote a stateful object.
*
* @see FlowDefinition
* @see FlowExecution
*
* @author Keith Donald
* @author Erwin Vervaet
*/
public interface FlowSession {
/**
* Returns the flow definition backing this session.
*/
public FlowDefinition getDefinition();
/**
* Returns the current state of this flow session. This value changes as the flow executes.
*/
public StateDefinition getState();
/**
* Return this session's local attributes; the basis for "flow scope" (flow session scope).
* @return the flow scope attributes
*/
public MutableAttributeMap getScope();
/**
* Returns a mutable map for data held in "view scope". Attributes in this map are cleared out when the current view
* state exits.
* @return view scope
* @throws IllegalStateException if this flow session is not currently in a view state
*/
public MutableAttributeMap getViewScope() throws IllegalStateException;
/**
* Returns the parent flow session in the current flow execution, or null if there is no parent flow
* session.
*/
public FlowSession getParent();
/**
* Returns whether this flow session is the root flow session in the ongoing flow execution. The root flow session
* does not have a parent flow session.
*/
public boolean isRoot();
}