weka.knowledgeflow.steps

Class BaseStep

java.lang.Object

weka.knowledgeflow.steps.BaseStep

All Implemented Interfaces:

Serializable, BaseStepExtender, Step

Direct Known Subclasses:

Appender, BaseSimpleDataVisualizer, Block, BoundaryPlotter, ClassAssigner, ClassifierPerformanceEvaluator, ClassValuePicker, ClustererPerformanceEvaluator, CrossValidationFoldMaker, DataGrid, DataVisualizer, Dummy, FlowByExpression, ImageSaver, ImageViewer, IncrementalClassifierEvaluator, InstanceStreamToBatchMaker, Join, MakeResourceIntensive, MemoryBasedDataSource, ModelPerformanceChart, Note, PredictionAppender, SerializedModelSaver, SetVariables, Sorter, StripChart, SubstringLabeler, SubstringReplacer, TestSetMaker, TextSaver, TextViewer, TrainingSetMaker, TrainTestSplitMaker, WekaAlgorithmWrapper

public abstract class BaseStep
extends Object
implements Step, BaseStepExtender, Serializable

Base class for implementations of Step to use. Provides handy functions that automatically setup the step's name and "about" info, provide access to the step's StepManager and for resolving environment variables.

Version:

$Revision: $

Author:

Mark Hall (mhall{[at]}pentaho{[dot]}com)

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
BaseStep() Constructor

Method Summary

Modifier and Type	Method and Description
String	environmentSubstitute(String source) Substitute the values of environment variables in the given string
String	getCustomEditorForStep() Return the fully qualified name of a custom editor component (JComponent) to use for editing the properties of the step.
Defaults	getDefaultSettings() Get default settings for the step (if any).
Map<String,String>	getInteractiveViewers() When running in a graphical execution environment a step can make one or more popup Viewer components available.
Map<String,StepInteractiveViewer>	getInteractiveViewersImpls() An alternative to getStepInteractiveViewers that returns a Map of instantiated StepInteractiveViewer objects.
String	getName() Get the name of this step
StepManager	getStepManager() Get the step manager for this step
String	globalInfo() Attempt to get default "about" information for this step by grabbing the toolTip from the KFStep annotation.
boolean	isResourceIntensive() Get whether this step is resource intensive (cpu/memory) or not.
boolean	isStopRequested() Convenience method that calls StepManager.isStopRequested()
Instances	outputStructureForConnectionType(String connectionName) If possible, get the output structure for the named connection type as a header-only set of instances.
void	processIncoming(Data data) Process an incoming data payload (if the step accepts incoming connections)
void	setName(String name) Set the name of this step
void	setStepIsResourceIntensive(boolean isResourceIntensive) Set whether this step is resource intensive (cpu/memory) or not.
void	setStepManager(StepManager manager) Set the step manager for this step
void	start() Start processing.
void	stop() Request that processing be stopped.

Methods inherited from class java.lang.Object

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

Methods inherited from interface weka.knowledgeflow.steps.Step

getIncomingConnectionTypes, getOutgoingConnectionTypes, stepInit

Methods inherited from interface weka.knowledgeflow.steps.BaseStepExtender

getIncomingConnectionTypes, getOutgoingConnectionTypes, stepInit

Constructor Detail

BaseStep

public BaseStep()

Constructor

Method Detail

globalInfo

public String globalInfo()

Attempt to get default "about" information for this step by grabbing the toolTip from the KFStep annotation.

Returns:

a default "about" info string if this step uses the KFStep annotation and null otherwise. Subclasses should override to provide more comprehensive about info

getStepManager

@NotPersistable
public StepManager getStepManager()

Get the step manager for this step

Specified by:

getStepManager in interface Step

Returns:

the step manager for this step

setStepManager

public void setStepManager(StepManager manager)

Set the step manager for this step

Specified by:

setStepManager in interface Step

Parameters:

manager - the step manager to use

setStepIsResourceIntensive

@ProgrammaticProperty
public void setStepIsResourceIntensive(boolean isResourceIntensive)

Set whether this step is resource intensive (cpu/memory) or not. This affects which executor service is used to execute the step's processing.

Parameters:

isResourceIntensive - true if this step is resource intensive.

isResourceIntensive

public boolean isResourceIntensive()

Get whether this step is resource intensive (cpu/memory) or not.

Returns:

true if this step is resource intensive

getName

public String getName()

Get the name of this step

Specified by:

getName in interface Step

Returns:

the name of this step

setName

@ProgrammaticProperty
public void setName(String name)

Set the name of this step

Specified by:

setName in interface Step

Parameters:

name - the name for this step

start

public void start()
           throws WekaException

Start processing. Subclasses should override this method if they can act as a start point in a flow.

Specified by:

start in interface BaseStepExtender

Specified by:

start in interface Step

Throws:

WekaException - if a problem occurs

stop

public void stop()

Request that processing be stopped. Subclasses should call isStopRequested() periodically to see if they should stop processing.

Specified by:

stop in interface Step

outputStructureForConnectionType

public Instances outputStructureForConnectionType(String connectionName)
                                           throws WekaException

If possible, get the output structure for the named connection type as a header-only set of instances. Can return null if the specified connection type is not representable as Instances or cannot be determined at present.

Specified by:

outputStructureForConnectionType in interface Step

Parameters:

connectionName - the name of the connection type to get the output structure for

Returns:

the output structure as a header-only Instances object

Throws:

WekaException - if a problem occurs

processIncoming

public void processIncoming(Data data)
                     throws WekaException

Process an incoming data payload (if the step accepts incoming connections)

Specified by:

processIncoming in interface BaseStepExtender

Specified by:

processIncoming in interface Step

Parameters:

data - the payload to process

Throws:

WekaException - if a problem occurs

getCustomEditorForStep

public String getCustomEditorForStep()

Return the fully qualified name of a custom editor component (JComponent) to use for editing the properties of the step. This method can return null, in which case the system will dynamically generate an editor using the GenericObjectEditor

Specified by:

getCustomEditorForStep in interface Step

Returns:

the fully qualified name of a step editor component

getInteractiveViewers

public Map<String,String> getInteractiveViewers()

When running in a graphical execution environment a step can make one or more popup Viewer components available. These might be used to display results, graphics etc. Returning null indicates that the step has no such additional graphical views. The map returned by this method should be keyed by action name (e.g. "View results"), and values should be fully qualified names of the corresponding StepInteractiveView implementation. Furthermore, the contents of this map can (and should) be dependent on whether a particular viewer should be made available - i.e. if execution hasn't occurred yet, or if a particular incoming connection type is not present, then it might not be possible to view certain results. Viewers can implement StepInteractiveView directly (in which case they need to extends JPanel), or extends the AbstractInteractiveViewer class. The later extends JPanel, uses a BorderLayout, provides a "Close" button and a method to add additional buttons.

Specified by:

getInteractiveViewers in interface Step

Returns:

a map of viewer component names, or null if this step has no graphical views

getInteractiveViewersImpls

public Map<String,StepInteractiveViewer> getInteractiveViewersImpls()

An alternative to getStepInteractiveViewers that returns a Map of instantiated StepInteractiveViewer objects. Generally, getInteractiveViewers() is the preferred mechanism to specify any interactive viewers, as it does not require Steps to import and instantiate GUI classes. However, in some cases it might be unavoidable (e.g. Groovy script compilation involves custom classloaders), in these cases this method can be used instead.

Specified by:

getInteractiveViewersImpls in interface Step

Returns:

a map of instantiated instances of StepInteractiveViewers

getDefaultSettings

public Defaults getDefaultSettings()

Get default settings for the step (if any). Returning null indicates that the step has no user-editable defaults.

Specified by:

getDefaultSettings in interface Step

Returns:

the default settings

isStopRequested

public boolean isStopRequested()

Convenience method that calls StepManager.isStopRequested()

Returns:

true if the execution environment has requested processing to stop

environmentSubstitute

public String environmentSubstitute(String source)

Substitute the values of environment variables in the given string

Parameters:

source - the source string to substitute in

Returns:

the source string with all known environment variables resolved