SCXMLExecutor (Apache Commons SCXML 2.0-SNAPSHOT API)

java.lang.Object
- org.apache.commons.scxml2.SCXMLExecutor

All Implemented Interfaces:

SCXMLIOProcessor
```
public class SCXMLExecutor
extends Object
implements SCXMLIOProcessor
```
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.scxml2.semantics.SCXMLSemanticsImpl

The executor uses SCXMLExecutionContext to manage the state and provide all the services to the SCXMLSemantics implementation.

See Also:
SCXMLSemantics

Field Summary
- Fields inherited from interface org.apache.commons.scxml2.SCXMLIOProcessor
  DEFAULT_EVENT_PROCESSOR, EVENT_PROCESSOR_ALIAS_PREFIX, INTERNAL_EVENT_PROCESSOR, PARENT_EVENT_PROCESSOR, SCXML_EVENT_PROCESSOR, SCXML_SESSION_EVENT_PROCESSOR_PREFIX

Constructor Summary

Constructors
Constructor and Description
`SCXMLExecutor()` Convenience constructor.
`SCXMLExecutor(Evaluator expEvaluator, EventDispatcher evtDisp, ErrorReporter errRep)` Constructor.
`SCXMLExecutor(Evaluator expEvaluator, EventDispatcher evtDisp, ErrorReporter errRep, SCXMLSemantics semantics)` Constructor.
`SCXMLExecutor(SCXMLExecutor parentSCXMLExecutor)` Constructor using a parent SCXMLExecutor

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addEvent(TriggerEvent evt)` Add a new external event, which may be done concurrently, and even when the current SCInstance is detached.
`void`	`addListener(Observable observable, SCXMLListener listener)` Add a listener to the `Observable`.
`void`	`attachInstance(SCInstance instance)` Re-attach a previously detached SCInstance.
`SCInstance`	`detachInstance()` Detach the current SCInstance to allow external serialization.
`protected void`	`eventStep(TriggerEvent event)`
`ErrorReporter`	`getErrorReporter()` Get the environment specific error reporter.
`Evaluator`	`getEvaluator()` Get the expression evaluator in use.
`EventDispatcher`	`getEventdispatcher()` Get the event dispatcher.
`Context`	`getGlobalContext()` Get the global context for the state machine execution.
`NotificationRegistry`	`getNotificationRegistry()` Get the notification registry.
`protected SCXMLExecutor`	`getParentSCXMLExecutor()`
`int`	`getPendingEvents()`
`Context`	`getRootContext()` Get the root context for the state machine execution.
`protected SCInstance`	`getSCInstance()` Get the state chart instance for this executor.
`SCXML`	`getStateMachine()` Get the state machine that is being executed.
`Status`	`getStatus()` Get the current state machine instance status.
`void`	`go()` Initiate state machine execution.
`boolean`	`hasPendingEvents()`
`boolean`	`isCheckLegalConfiguration()`
`boolean`	`isRunning()`
`boolean`	`isSingleContext()`
`protected void`	`logState()` Log the current set of active states.
`void`	`registerInvokerClass(String type, Class<? extends Invoker> invokerClass)` Register an Invoker for this target type.
`void`	`removeListener(Observable observable, SCXMLListener listener)` Remove this listener from the `Observable`.
`void`	`reset()` Clear all state and begin executing the state machine
`void`	`setCheckLegalConfiguration(boolean checkLegalConfiguration)` Set if the SCXML configuration should be checked before execution (default = true)
`void`	`setConfiguration(Set<String> atomicStateIds)` Initializes the state machine with a specific active configuration This will first (re)initialize the current state machine: clearing all variable contexts, histories and current status, and clones the SCXML root datamodel into the root context.
`void`	`setErrorReporter(ErrorReporter errorReporter)` Set or replace the error reporter
`void`	`setEvaluator(Evaluator evaluator)` Set or replace the expression evaluator If the state machine instance has been initialized before, it will be initialized again, destroying all existing state!
`void`	`setEventdispatcher(EventDispatcher eventdispatcher)` Set or replace the event dispatch
`void`	`setRootContext(Context rootContext)` Set the root context for the state machine execution.
`void`	`setSingleContext(boolean singleContext)`
`void`	`setStateMachine(SCXML stateMachine)` Set or replace the state machine to be executed If the state machine instance has been initialized before, it will be initialized again, destroying all existing state!
`void`	`triggerEvent(TriggerEvent evt)` Convenience method when only one event needs to be triggered.
`void`	`triggerEvents()` Trigger all pending and incoming events, until there are no more pending events
`void`	`triggerEvents(TriggerEvent[] evts)` The worker method.
`void`	`unregisterInvokerClass(String type)` 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()
```
    Convenience constructor.
  - 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(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
  - SCXMLExecutor
```
public SCXMLExecutor(SCXMLExecutor parentSCXMLExecutor)
```
    Constructor using a parent SCXMLExecutor
    
    Parameters:
    parentSCXMLExecutor - the parent SCXMLExecutor
- Method Detail
  - getParentSCXMLExecutor
```
protected SCXMLExecutor getParentSCXMLExecutor()
```
    Returns:
    the parent SCXMLExecutor (if any)
  - getStatus
```
public Status getStatus()
```
    Get the current state machine instance status.
    
    Returns:
    The current Status
  - setConfiguration
```
public void setConfiguration(Set<String> atomicStateIds)
                      throws ModelException
```
    Initializes the state machine with a specific active configuration
    This will first (re)initialize the current state machine: clearing all variable contexts, histories and current status, and clones the SCXML root datamodel into the root context.
    
    Parameters:
    atomicStateIds - The set of atomic state ids for the state machine
    
    Throws:
    
    ModelException - when the state machine hasn't been properly configured yet, when an unknown or illegal stateId is specified, or when the specified active configuration does not represent a legal configuration.
    See Also:
    SCInstance#initialize()}, SCXMLSemantics#isLegalConfiguration(java.util.Set, ErrorReporter)}
  - setEvaluator
```
public void setEvaluator(Evaluator evaluator)
                  throws ModelException
```
    Set or replace the expression evaluator
    If the state machine instance has been initialized before, it will be initialized again, destroying all existing state!
    
    Also the external event queue will be cleared.
    
    Parameters:
    evaluator - The evaluator to set
    
    Throws:
    
    ModelException - if attempting to set a null value or the state machine instance failed to re-initialize
  - getEvaluator
```
public Evaluator getEvaluator()
```
    Get the expression evaluator in use.
    
    Returns:
    Evaluator The evaluator in use.
  - getRootContext
```
public Context getRootContext()
```
    Get the root context for the state machine execution.
    The root context can be used for providing external data to the state machine
    
    Returns:
    Context The root context.
  - getGlobalContext
```
public Context getGlobalContext()
```
    Get the global context for the state machine execution.
    The global context is the top level context within the state machine itself and should be regarded and treated "read-only" from external usage.
    
    Returns:
    Context The global context.
  - setRootContext
```
public void setRootContext(Context rootContext)
```
    Set the root context for the state machine execution. NOTE: Should only be used before the executor is set in motion.
    
    Parameters:
    rootContext - The Context that ties to the host environment.
  - setSingleContext
```
public void setSingleContext(boolean singleContext)
                      throws ModelException
```
    Throws:
    
    ModelException
  - isSingleContext
```
public boolean isSingleContext()
```
  - 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 should not be altered once in use. 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)
                     throws ModelException
```
    Set or replace the state machine to be executed
    If the state machine instance has been initialized before, it will be initialized again, destroying all existing state!
    
    Also the external event queue will be cleared.
    
    Parameters:
    stateMachine - The state machine to set
    
    Throws:
    
    ModelException - if attempting to set a null value or the state machine instance failed to re-initialize
  - getErrorReporter
```
public ErrorReporter getErrorReporter()
```
    Get the environment specific error reporter.
    
    Returns:
    Returns the errorReporter.
  - setErrorReporter
```
public void setErrorReporter(ErrorReporter errorReporter)
```
    Set or replace the error reporter
    
    Parameters:
    errorReporter - The error reporter to set, if null a SimpleErrorReporter instance will be used instead
  - getEventdispatcher
```
public EventDispatcher getEventdispatcher()
```
    Get the event dispatcher.
    
    Returns:
    Returns the eventdispatcher.
  - setEventdispatcher
```
public void setEventdispatcher(EventDispatcher eventdispatcher)
```
    Set or replace the event dispatch
    
    Parameters:
    eventdispatcher - The event dispatcher to set, if null a SimpleDispatcher instance will be used instead
  - setCheckLegalConfiguration
```
public void setCheckLegalConfiguration(boolean checkLegalConfiguration)
```
    Set if the SCXML configuration should be checked before execution (default = true)
    
    Parameters:
    checkLegalConfiguration - flag to set
  - isCheckLegalConfiguration
```
public boolean isCheckLegalConfiguration()
```
    Returns:
    if the SCXML configuration will be checked before execution
  - getNotificationRegistry
```
public NotificationRegistry getNotificationRegistry()
```
    Get the notification registry.
    
    Returns:
    The notification registry.
  - addListener
```
public void addListener(Observable observable,
               SCXMLListener listener)
```
    Add a listener to the Observable.
    
    Parameters:
    observable - The Observable to attach the listener to.
    listener - The SCXMLListener.
  - removeListener
```
public void removeListener(Observable observable,
                  SCXMLListener listener)
```
    Remove this listener from the Observable.
    
    Parameters:
    observable - The Observable.
    listener - The SCXMLListener to be removed.
  - registerInvokerClass
```
public void registerInvokerClass(String type,
                        Class<? extends Invoker> invokerClass)
```
    Register an Invoker for this target type.
    
    Parameters:
    type - The target type (specified by "type" attribute of the invoke element).
    invokerClass - The Invoker class.
  - unregisterInvokerClass
```
public void unregisterInvokerClass(String type)
```
    Remove the Invoker registered for this target type (if there is one registered).
    
    Parameters:
    type - The target type (specified by "type" attribute of the invoke element).
  - detachInstance
```
public SCInstance detachInstance()
```
    Detach the current SCInstance to allow external serialization.
    attachInstance(SCInstance) can be used to re-attach a previously detached instance
    
    Note: until an instance is re-attached, no operations are allowed (and probably throw exceptions) except for addEvent(TriggerEvent) which might still be used (concurrently) by running Invokers, or hasPendingEvents() to check for possible pending events.
    
    Returns:
    the detached instance
  - attachInstance
```
public void attachInstance(SCInstance instance)
```
    Re-attach a previously detached SCInstance.
    Note: an already attached instance will get overwritten (and thus lost).
    
    Parameters:
    instance - An previously detached SCInstance
  - isRunning
```
public boolean isRunning()
```
    Returns:
    Returns true if the state machine is running
  - go
```
public void go()
        throws ModelException
```
    Initiate state machine execution.
    
    Throws:
    
    ModelException - in case there is a fatal SCXML object model problem.
  - reset
```
public void reset()
           throws ModelException
```
    Clear all state and begin executing the state machine
    
    Throws:
    
    ModelException - if the state machine instance failed to initialize
  - addEvent
```
public void addEvent(TriggerEvent evt)
```
    Add a new external event, which may be done concurrently, and even when the current SCInstance is detached.
    No processing of the vent will be done, until the next triggerEvent methods is invoked.
    
    Specified by:
    
    addEvent in interface SCXMLIOProcessor
    
    Parameters:
    evt - an external event
  - hasPendingEvents
```
public boolean hasPendingEvents()
```
    Returns:
    Returns true if there are pending external events to be processed.
  - getPendingEvents
```
public int getPendingEvents()
```
    Returns:
    Returns the current number of pending external events to be processed.
  - 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.
  - 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.
  - triggerEvents
```
public void triggerEvents()
                   throws ModelException
```
    Trigger all pending and incoming events, until there are no more pending events
    
    Throws:
    
    ModelException - in case there is a fatal SCXML object model problem.
  - eventStep
```
protected void eventStep(TriggerEvent event)
                  throws ModelException
```
    Throws:
    
    ModelException
  - getSCInstance
```
protected SCInstance getSCInstance()
```
    Get the state chart instance for this executor.
    
    Returns:
    The SCInstance for this executor.
  - logState
```
protected void logState()
```
    Log the current set of active states.

Class SCXMLExecutor

Field Summary

Fields inherited from interface org.apache.commons.scxml2.SCXMLIOProcessor

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SCXMLExecutor

SCXMLExecutor

SCXMLExecutor

SCXMLExecutor

Method Detail

getParentSCXMLExecutor

getStatus

setConfiguration

setEvaluator

getEvaluator

getRootContext

getGlobalContext

setRootContext

setSingleContext

isSingleContext

getStateMachine

setStateMachine

getErrorReporter

setErrorReporter

getEventdispatcher

setEventdispatcher

setCheckLegalConfiguration

isCheckLegalConfiguration

getNotificationRegistry

addListener

removeListener

registerInvokerClass

unregisterInvokerClass

detachInstance

attachInstance

isRunning

go

reset

addEvent

hasPendingEvents

getPendingEvents

triggerEvent

triggerEvents

triggerEvents

eventStep

getSCInstance

logState