Extension Point Plugins

Extension point plugins, introduced in the Kettle 5 API, allow someone to add plugins to the Kettle ecosystem for execution at specific points in the Kettle code.

The plugin implements the ExtensionPointInterface interface:

public interface ExtensionPointInterface {

  /**
   * This method is called by the Kettle code
   * @param log the logging channel to log debugging information to
   * @param object The subject object that is passed to the plugin code
   * @throws KettleException In case the plugin decides that an error has occurred and the parent process should stop.
   */
  public void callExtensionPoint(LogChannelInterface log, Object object) throws KettleException;
}

The following extension points are available by default (see the KettleExtensionPoint enum):

ID	Description	Java object passed	Since version
TransformationPrepareExecution	A transformation begins to prepare execution	Trans	5.0
TransformationStartThreads	A transformation begins to start	Trans	5.0
TransformationStart	A transformation has started	Trans	5.0
TransformationFinish	A transformation finishes	Trans	5.0
TransformationMetaLoaded	Transformation metadata was loaded	TransMeta	5.0
TransPainterArrow	Draw additional information on top of a transformation hop (arrow)	TransPainterExtension	5.0
TransPainterStep	Draw additional information on top of a transformation step icon	TransPainterExtension	5.0
TransPainterStart	Draw transformation or plugin metadata at the start (below the rest)	TransPainter	5.1
TransPainterEnd	Draw transformation or plugin metadata at the end (on top of all the rest)	TransPainter	5.1
SpoonTransMetaExecutionStart	Spoon initiates the execution of a transformation	TransMeta	5.0
SpoonTransExecutionConfiguration	Right before the configuration of a transformation to be executed takes place in Spoon	TransExecutionConfiguration	5.0
JobStart	A job starts	Job	5.0
JobFinish	A job finishes	Job	5.0
JobBeforeJobEntryExecution	Before a job entry executes	JobExecutionExtension	5.0
JobAfterJobEntryExecution	After a job entry executes	JobExecutionExtension	5.0
JobBeginProcessing	Start of a job at the end of the log table handling	JobExecutionExtension	5.0
JobPainterArrow	Draw additional information on top of a job hop (arrow)	JobPainterExtension	5.0
TransPainterJobEntry	Draw additional information on top of a job entry copy icon	JobPainterExtension	5.0
JobGraphJobEntrySetMenu	Manipulate the menu on right click on a job entry	JobGraphJobEntryMenuExtension	5.0
JobPainterStart	Draw job or plugin metadata at the start (below the rest)	JobPainter	5.1
JobPainterEnd	Draw job or plugin metadata at the end (on top of all the rest)	JobPainter	5.1
JobMetaLoaded	Job metadata was loaded	JobMeta	5.0
SpoonJobMetaExecutionStart	Spoon initiates the execution of a job	JobMeta	5.0
SpoonJobExecutionConfiguration	Right before the configuration of a job to be executed takes place in Spoon	JobExecutionConfiguration	5.0
DatabaseConnected	After a successful connection to a database	Database	5.0
DatabaseDisconnected	After a successful disconnection from a database	Database	5.0
StepBeforeInitialize	Before a step is about to be initialized	StepInitThread	5.0
StepAfterInitialize	After a step is initialized	StepInitThread	5.0
StepBeforeStart	Before a step is about to be started	StepMetaDataCombi	5.0
StepFinished	After a step has finished	StepMetaDataCombi	5.0

The class implementing the ExtensionPointInterface should be annotated with @ExtensionPoint. The following information needs to be passed:

id : the unique ID of the plugin
extensionPointId: the extension point ID, see the table above for the available extension points
description: a description so that folks can see what it does in the plugin browser

PDI Extension Point Plugins

Extension Point Plugins