org.apache.commons.scxml
Class SCXMLExecutor

java.lang.Object
  org.apache.commons.scxml.SCXMLExecutor

All Implemented Interfaces:

Serializable

public class SCXMLExecutor
extends Object
implements Serializable

The SCXML "engine" that executes SCXML documents. The particular semantics used by this engine for executing the SCXML are encapsulated in the SCXMLSemantics implementation that it uses.

The default implementation is org.apache.commons.scxml.semantics.SCXMLSemanticsImpl

See Also:

SCXMLSemantics, Serialized Form

Constructor Summary

SCXMLExecutor()
Convenience constructor.

SCXMLExecutor(Evaluator expEvaluator, EventDispatcher evtDisp, ErrorReporter errRep)
Constructor.

SCXMLExecutor(Evaluator expEvaluator, EventDispatcher evtDisp, ErrorReporter errRep, SCXMLSemantics semantics)
Constructor.

Method Summary

void	addListener(SCXML scxml, SCXMLListener listener) Add a listener to the document root.
void	addListener(Transition transition, SCXMLListener listener) Add a listener to this transition.
void	addListener(TransitionTarget transitionTarget, SCXMLListener listener) Add a listener to this transition target.
Status	getCurrentStatus() Get the current status.
ErrorReporter	getErrorReporter() Get the environment specific error reporter.
Evaluator	getEvaluator() Get the expression evaluator in use.
EventDispatcher	getEventdispatcher() Get the event dispatcher.
Context	getRootContext() Get the root context for this execution.
SCXML	getStateMachine() Get the state machine that is being executed.
void	go() Initiate state machine execution.
boolean	isSuperStep() Use "super-step", default is true (that is, run-to-completion is default).
void	registerInvokerClass(String targettype, Class invokerClass) Register an Invoker for this target type.
void	removeListener(SCXML scxml, SCXMLListener listener) Remove this listener from the document root.
void	removeListener(Transition transition, SCXMLListener listener) Remove this listener for this transition.
void	removeListener(TransitionTarget transitionTarget, SCXMLListener listener) Remove this listener for this transition target.
void	reset() Clear all state and begin from "initialstate" indicated on root SCXML element.
void	setErrorReporter(ErrorReporter errorReporter) Set the environment specific error reporter.
void	setEvaluator(Evaluator evaluator) Set the expression evaluator.
void	setEventdispatcher(EventDispatcher eventdispatcher) Set the event dispatcher.
void	setRootContext(Context rootContext) Set the root context for this execution.
void	setStateMachine(SCXML stateMachine) Set the state machine to be executed.
void	setSuperStep(boolean superStep) Set the super step.
void	triggerEvent(TriggerEvent evt) Convenience method when only one event needs to be triggered.
void	triggerEvents(TriggerEvent[] evts) The worker method.
void	unregisterInvokerClass(String targettype) Remove the Invoker registered for this target type (if there is one registered).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SCXMLExecutor

public SCXMLExecutor(Evaluator expEvaluator,
                     EventDispatcher evtDisp,
                     ErrorReporter errRep)

Constructor.

Parameters:

expEvaluator - The expression evaluator

evtDisp - The event dispatcher

errRep - The error reporter

SCXMLExecutor

public SCXMLExecutor()

Convenience constructor.

SCXMLExecutor

public SCXMLExecutor(Evaluator expEvaluator,
                     EventDispatcher evtDisp,
                     ErrorReporter errRep,
                     SCXMLSemantics semantics)

Constructor.

Parameters:

expEvaluator - The expression evaluator

evtDisp - The event dispatcher

errRep - The error reporter

semantics - The SCXML semantics

Method Detail

triggerEvents

public void triggerEvents(TriggerEvent[] evts)
                   throws ModelException

The worker method. Re-evaluates current status whenever any events are triggered.

Parameters:

evts - an array of external events which triggered during the last time quantum

Throws:

ModelException - in case there is a fatal SCXML object model problem.

triggerEvent

public void triggerEvent(TriggerEvent evt)
                  throws ModelException

Convenience method when only one event needs to be triggered.

Parameters:

evt - the external events which triggered during the last time quantum

Throws:

ModelException - in case there is a fatal SCXML object model problem.

reset

public void reset()
           throws ModelException

Clear all state and begin from "initialstate" indicated on root SCXML element.

Throws:

ModelException - in case there is a fatal SCXML object model problem.

getCurrentStatus

public Status getCurrentStatus()

Get the current status.

Returns:

The current Status

setEvaluator

public void setEvaluator(Evaluator evaluator)

Set the expression evaluator. NOTE: Should only be used before the executor is set in motion.

Parameters:

evaluator - The evaluator to set.

getEvaluator

public Evaluator getEvaluator()

Get the expression evaluator in use.

Returns:

Evaluator The evaluator in use.

setRootContext

public void setRootContext(Context rootContext)

Set the root context for this execution. NOTE: Should only be used before the executor is set in motion.

Parameters:

rootContext - The Context that ties to the host environment.

getRootContext

public Context getRootContext()

Get the root context for this execution.

Returns:

Context The root context.

getStateMachine

public SCXML getStateMachine()

Get the state machine that is being executed. NOTE: This is the state machine definition or model used by this executor instance. It may be shared across multiple executor instances and as a best practice, should not be altered. Also note that manipulation of instance data for the executor should happen through its root context or state contexts only, never through the direct manipulation of any Datamodels associated with this state machine definition.

Returns:

Returns the stateMachine.

setStateMachine

public void setStateMachine(SCXML stateMachine)

Set the state machine to be executed. NOTE: Should only be used before the executor is set in motion.

Parameters:

stateMachine - The stateMachine to set.

go

public void go()
        throws ModelException

Initiate state machine execution.

Throws:

ModelException - in case there is a fatal SCXML object model problem.

getErrorReporter

public ErrorReporter getErrorReporter()

Get the environment specific error reporter.

Returns:

Returns the errorReporter.

setErrorReporter

public void setErrorReporter(ErrorReporter errorReporter)

Set the environment specific error reporter.

Parameters:

errorReporter - The errorReporter to set.

getEventdispatcher

public EventDispatcher getEventdispatcher()

Get the event dispatcher.

Returns:

Returns the eventdispatcher.

setEventdispatcher

public void setEventdispatcher(EventDispatcher eventdispatcher)

Set the event dispatcher.

Parameters:

eventdispatcher - The eventdispatcher to set.

isSuperStep

public boolean isSuperStep()

Use "super-step", default is true (that is, run-to-completion is default).

Returns:

Returns the superStep property.

See Also:

setSuperStep(boolean)

setSuperStep

public void setSuperStep(boolean superStep)

Set the super step.

Parameters:

superStep - if true, the internal derived events are also processed (run-to-completion); if false, the internal derived events are stored in the CurrentStatus property and processed within the next triggerEvents() invocation, also the immediate (empty event) transitions are deferred until the next step

addListener

public void addListener(SCXML scxml,
                        SCXMLListener listener)

Add a listener to the document root.

Parameters:

scxml - The document root to attach listener to.

listener - The SCXMLListener.

removeListener

public void removeListener(SCXML scxml,
                           SCXMLListener listener)

Remove this listener from the document root.

Parameters:

scxml - The document root.

listener - The SCXMLListener to be removed.

addListener

public void addListener(TransitionTarget transitionTarget,
                        SCXMLListener listener)

Add a listener to this transition target.

Parameters:

transitionTarget - The TransitionTarget to attach listener to.

listener - The SCXMLListener.

removeListener

public void removeListener(TransitionTarget transitionTarget,
                           SCXMLListener listener)

Remove this listener for this transition target.

Parameters:

transitionTarget - The TransitionTarget.

listener - The SCXMLListener to be removed.

addListener

public void addListener(Transition transition,
                        SCXMLListener listener)

Add a listener to this transition.

Parameters:

transition - The Transition to attach listener to.

listener - The SCXMLListener.

removeListener

public void removeListener(Transition transition,
                           SCXMLListener listener)

Remove this listener for this transition.

Parameters:

transition - The Transition.

listener - The SCXMLListener to be removed.

registerInvokerClass

public void registerInvokerClass(String targettype,
                                 Class invokerClass)

Register an Invoker for this target type.

Parameters:

targettype - The target type (specified by "targettype" attribute of <invoke> tag).

invokerClass - The Invoker Class.

unregisterInvokerClass

public void unregisterInvokerClass(String targettype)

Remove the Invoker registered for this target type (if there is one registered).

Parameters:

targettype - The target type (specified by "targettype" attribute of <invoke> tag).