org.apache.commons.workflow.core
Class IfStep

java.lang.Object
  extended by org.apache.commons.workflow.base.BaseStep
      extended by org.apache.commons.workflow.base.DescriptorStep
          extended by org.apache.commons.workflow.base.BaseBlock
              extended by org.apache.commons.workflow.core.IfStep
All Implemented Interfaces:
Block, Descriptors, Owner, Step
Direct Known Subclasses:
IfAnyStep, IfNotAnyStep, IfNotStep

public class IfStep
extends BaseBlock

Evaluate properties specified by the associated Descriptors, and execute the nested Steps if and only if they ALL 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
IfStep()
          Construct a default instance of this Step.
IfStep(String id)
          Construct an instance of this Step with the specified identifier.
IfStep(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.
 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, subsequent
 
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.Step
getId, getNextStep, getOwner, getPreviousStep, setId, setNextStep, setOwner, setPreviousStep
 

Constructor Detail

IfStep

public IfStep()
Construct a default instance of this Step.


IfStep

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

Parameters:
id - Step identifier

IfStep

public IfStep(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


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