org.dcs.query_process

Class Script_Engine

java.lang.Object

org.dcs.query_process.Script_Engine

public class Script_Engine
extends java.lang.Object

This class will mediate between the different components of a script process. This is a very lightweight processor that can only suggest the next process step, but does not actually evaluate anything itself.

The engine will also only traverse the script once, where another more sophisticated engine would have to recognise control loops and when to repeat any sections.

Author:

Kieran Greer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	Script_Engine.ListCounter This class stores a list with the current search position in the list.

Constructor Summary

Constructors

Constructor and Description
Script_Engine() Create a new instance of Script_Engine

Method Summary

Modifier and Type	Method and Description
boolean	getIsFinished() Return true if there are still script elements to process and the script has not been terminated already.
Script_Event	nextProcessStep() Get the next set of possible process steps from the current position.
Script_Event	nextProcessStep(boolean pop) Get the next set of possible process steps from the current position.
void	resetValues(java.util.ArrayList<Script_Event> eventList) Reset the values for a new script execution.
void	setIsFinished() Set isFinished to true, in case need to terminate a script early.

Methods inherited from class java.lang.Object

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

Constructor Detail

Script_Engine

public Script_Engine()

Create a new instance of Script_Engine

Method Detail

resetValues

public void resetValues(java.util.ArrayList<Script_Event> eventList)

Reset the values for a new script execution.

Parameters:

eventList - the base set of events to process in sequence.

setIsFinished

public void setIsFinished()

Set isFinished to true, in case need to terminate a script early.

getIsFinished

public boolean getIsFinished()
                      throws java.lang.Exception

Return true if there are still script elements to process and the script has not been terminated already.

Returns:

true if not at the end of the process stack and still to run.

Throws:

java.lang.Exception - any error.

nextProcessStep

public Script_Event nextProcessStep()
                             throws java.lang.Exception

Get the next set of possible process steps from the current position. Permanently update the counter positions.

Returns:

the next operation to execute. Sequential only, considered at the moment.

Throws:

java.lang.Exception - any error.

nextProcessStep

public Script_Event nextProcessStep(boolean pop)
                             throws java.lang.Exception

Get the next set of possible process steps from the current position.

Parameters:

pop - if true retrieve next element and permanently update counters or lists. If false, only look for next element, but do not update current position (pop off the list).

Returns:

the next operation to execute. Sequential only, considered at the moment.

Throws:

java.lang.Exception - any error.