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
TransformationPrepareExecution	A transformation begins to prepare execution	Trans
TransformationStartThreads	A transformation begins to start	Trans
TransformationStart	A transformation has started	Trans
TransformationFinish	A transformation finishes	Trans
TransformationMetaLoaded	Transformation metadata was loaded	TransMeta
SpoonTransMetaExecutionStart	Spoon initiates the execution of a transformation	TransMeta
SpoonTransExecutionConfiguration	Right before the configuration of a transformation to be executed takes place in Spoon	TransExecutionConfiguration
JobStart	A job starts	Job
JobFinish	A job finishes	Job
JobBeforeJobEntryExecution	Before a job entry executes	JobExecutionExtension
JobAfterJobEntryExecution	After a job entry executes	JobExecutionExtension
JobBeginProcessing	Start of a job at the end of the log table handling	JobExecutionExtension
JobPainterArrow	Draw additional information on top of a job hop (arrow)	JobPainterExtension
JobGraphJobEntrySetMenu	Manipulate the menu on right click on a job entry	JobGraphJobEntryMenuExtension
JobMetaLoaded	Job metadata was loaded	JobMeta
SpoonJobMetaExecutionStart	Spoon initiates the execution of a job	JobMeta
SpoonJobExecutionConfiguration	Right before the configuration of a job to be executed takes place in Spoon	JobExecutionConfiguration
DatabaseConnected	After a successful connection to a database	Database
DatabaseDisconnected	After a successful disconnection from a database	Database
StepBeforeInitialize	Before a step is about to be initialized	StepInitThread
StepAfterInitialize	After a step is initialized	StepInitThread
StepBeforeStart	Before a step is about to be started	StepMetaDataCombi
StepFinished	After a step has finished	StepMetaDataCombi

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