org.apache.commons.workflow.core
Class WhileStep

java.lang.Object
  org.apache.commons.workflow.base.BaseStep
      org.apache.commons.workflow.base.DescriptorStep
          org.apache.commons.workflow.base.BaseBlock
              org.apache.commons.workflow.core.WhileStep

All Implemented Interfaces:

Block, Descriptors, Iterator, Owner, Step

Direct Known Subclasses:

WhileAnyStep, WhileNotAnyStep, WhileNotStep

public class WhileStep
extends BaseBlock
implements Iterator

Repeatedly evaluate the properties specified by the associated Descriptors, and execute the nested Steps if and only if ALL of them evaluate to a positive result. To avoid non-deterministic evaluation stack behavior, all of the specified Descriptors are always evaluated exactly once.

Version:

$Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $

Author:

Craig R. McClanahan

Field Summary

Fields inherited from class org.apache.commons.workflow.base.BaseBlock

firstStep, lastStep

Fields inherited from class org.apache.commons.workflow.base.DescriptorStep

descriptors

Fields inherited from class org.apache.commons.workflow.base.BaseStep

id, nextStep, owner, previousStep

Constructor Summary

WhileStep()
Construct a default instance of this Step.

WhileStep(String id)
Construct an instance of this Step with the specified identifier.

WhileStep(String id, Descriptor descriptor)
Construct a fully configured instance of this Step.

Method Summary

protected boolean	evaluate(Context context) Evaluate the condition specified by the Descriptors associated with this Block, and return the resulting boolean value.
protected void	initial(Context context) Process the initial entry into this Block.
protected void	subsequent(Context context, BlockState state) Process the return from nested execution of the Steps assocaited with this Block.
String	toString() Render a string representation of this Step.

Methods inherited from class org.apache.commons.workflow.base.BaseBlock

addStep, clearSteps, execute, findStep, getFirstStep, getLastStep, getSteps, setSteps, state

Methods inherited from class org.apache.commons.workflow.base.DescriptorStep

addDescriptor, findDescriptors, removeDescriptor

Methods inherited from class org.apache.commons.workflow.base.BaseStep

getId, getNextStep, getOwner, getPreviousStep, setId, setNextStep, setOwner, setPreviousStep

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.workflow.Owner

addStep, clearSteps, findStep, getFirstStep, getLastStep, getSteps, setSteps

Methods inherited from interface org.apache.commons.workflow.Step

execute, getId, getNextStep, getOwner, getPreviousStep, setId, setNextStep, setOwner, setPreviousStep

Constructor Detail

WhileStep

public WhileStep()

Construct a default instance of this Step.

WhileStep

public WhileStep(String id)

Construct an instance of this Step with the specified identifier.

Parameters:

id - Step identifier

WhileStep

public WhileStep(String id,
                 Descriptor descriptor)

Construct a fully configured instance of this Step.

Parameters:

id - Step identifier of this step

descriptor - Initial descriptor to be added

Method Detail

toString

public String toString()

Render a string representation of this Step.

Overrides:

toString in class Object

evaluate

protected boolean evaluate(Context context)

Evaluate the condition specified by the Descriptors associated with this Block, and return the resulting boolean value.

Overrides:

evaluate in class BaseBlock

Parameters:

context - Context within which to evaluate the descriptors

initial

protected void initial(Context context)

Process the initial entry into this Block.

Overrides:

initial in class BaseBlock

Parameters:

context - Context within which to evaluate the condition

subsequent

protected void subsequent(Context context,
                          BlockState state)

Process the return from nested execution of the Steps assocaited with this Block.

Overrides:

subsequent in class BaseBlock

Parameters:

context - Context within which to evaluate the condition

state - BlockState for our block