org.springframework.webflow.definition.FlowDefinition 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.definition;
/**
* The definition of a flow, a program that when executed carries out the orchestration of a task on behalf of a single
* client.
*
* A flow definition is a reusable, self-contained controller module that defines a blue print for an executable user
* task. Flows typically orchestrate controlled navigations or dialogs within web applications to guide users through
* fulfillment of a business process/goal that takes place over a series of steps, modeled as states.
*
* Structurally a flow definition is composed of a set of states. A {@link StateDefinition state} is a point in a flow
* where a behavior is executed; for example, showing a view, executing an action, spawning a subflow, or terminating
* the flow. Different types of states execute different behaviors in a polymorphic fashion. Most states are
* {@link TransitionableStateDefinition transitionable states}, meaning they can respond to events by taking the flow
* from one state to another.
*
* Each flow has exactly one {@link #getStartState() start state} which defines the starting point of the program.
*
* This interface exposes the flow's identifier, states, and other definitional attributes. It is suitable for
* introspection by tools as well as user-code at flow execution time.
*
* Flow definitions may be annotated with attributes.
*
* @author Keith Donald
* @author Erwin Vervaet
*/
public interface FlowDefinition extends Annotated {
/**
* Returns the unique id of this flow.
* @return the flow id
*/
public String getId();
/**
* Return this flow's starting point.
* @return the start state
*/
public StateDefinition getStartState();
/**
* Returns the state definition with the specified id.
* @param id the state id
* @return the state definition
* @throws IllegalArgumentException if a state with this id does not exist
*/
public StateDefinition getState(String id) throws IllegalArgumentException;
}