org.springframework.webflow.engine
Class DecisionState

java.lang.Object
  org.springframework.webflow.engine.AnnotatedObject
      org.springframework.webflow.engine.State
          org.springframework.webflow.engine.TransitionableState
              org.springframework.webflow.engine.DecisionState

All Implemented Interfaces:

Annotated, StateDefinition, TransitionableStateDefinition

public class DecisionState
extends TransitionableState

A simple transitionable state that when entered will execute the first transition whose matching criteria evaluates to true in the context of the current request.

A decision state is a convenient, simple way to encapsulate reusable state transition logic in one place.

Author:

Keith Donald

Field Summary

Fields inherited from class org.springframework.webflow.engine.State

logger

Fields inherited from class org.springframework.webflow.engine.AnnotatedObject

CAPTION_PROPERTY, DESCRIPTION_PROPERTY

Constructor Summary

DecisionState(Flow flow, java.lang.String stateId)
Creates a new decision state.

Method Summary

protected ViewSelection

doEnter(RequestControlContext context) Specialization of State's doEnter template method that executes behaviour specific to this state type in polymorphic fashion.

Methods inherited from class org.springframework.webflow.engine.TransitionableState

appendToString, exit, getExitActionList, getRequiredTransition, getTransitions, getTransitionSet, onEvent, reenter

Methods inherited from class org.springframework.webflow.engine.State

enter, equals, getEntryActionList, getExceptionHandlerSet, getFlow, getId, getOwner, handleException, hashCode, isStartState, toString

Methods inherited from class org.springframework.webflow.engine.AnnotatedObject

getAttributeMap, getAttributes, getCaption, getDescription, setCaption, setDescription

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.springframework.webflow.definition.StateDefinition

getId, getOwner

Methods inherited from interface org.springframework.webflow.definition.Annotated

getAttributes, getCaption, getDescription

Constructor Detail

DecisionState

public DecisionState(Flow flow,
                     java.lang.String stateId)
              throws java.lang.IllegalArgumentException

Creates a new decision state.

Parameters:

flow - the owning flow

stateId - the state identifier (must be unique to the flow)

Throws:

java.lang.IllegalArgumentException - when this state cannot be added to given flow, e.g. because the id is not unique

Method Detail

doEnter

protected ViewSelection doEnter(RequestControlContext context)
                         throws FlowExecutionException

Specialization of State's doEnter template method that executes behaviour specific to this state type in polymorphic fashion.

Simply looks up the first transition that matches the state of the context and executes it.

Specified by:

doEnter in class State

Parameters:

context - the control context for the currently executing flow, used by this state to manipulate the flow execution

Returns:

a view selection containing model and view information needed to render the results of the state execution

Throws:

FlowExecutionException - if an exception occurs in this state