Package org.pentaho.di.trans.step

Class BaseStepHelper

java.lang.Object

org.pentaho.di.trans.step.BaseStepHelper

All Implemented Interfaces:

StepHelperInterface

Direct Known Subclasses:

CalculatorHelper, CsvInputHelper, DatabaseLookupHelper, DenormaliserStepHelper, FormulaHelper, GetFilesRowCountHelper, GroupByHelper, InsertUpdateHelper, JobExecutorHelper, MappingHelper, MergeJoinHelper, MergeRowsHelper, RandomValueStepHelper, SelectValuesHelper, SimpleMappingHelper, SingleThreaderHelper, StreamLookupStepHelper, SystemDataStepHelper, TableInputHelper, TableOutputHelper, TextFileInputHelper, TextFileOutputHelper, TransExecutorHelper, UpdateHelper

public abstract class BaseStepHelper
extends Object
implements StepHelperInterface

Base implementation of StepHelperInterface providing shared infrastructure for executing UI-triggered "step actions" and other common methods.

Step actions are step-specific, non-runtime operations initiated from a step dialog (e.g. fetching external metadata, validating configuration, testing connections). They do not participate in transformation execution.

This class centralizes:

• Acquisition of a LogChannelInterface for consistent logging
• Template handling in stepAction(String, TransMeta, java.util.Map) including:
  • Delegation to handleStepAction(String, TransMeta, java.util.Map)
  • Automatic population of standard response status fields defined in the interface
  • Error trapping and failure status assignment
• Utility to evaluate failure state via isFailedResponse(org.json.simple.JSONObject)

Subclasses implement only the step-specific logic in handleStepAction(String, TransMeta, java.util.Map).

See Also:

• StepHelperInterface

Field Summary

Fields

Modifier and Type	Field	Description
static final String	IS_TRANS_REFERENCE
static final String	IS_VALID_REFERENCE
protected final org.pentaho.di.core.logging.LogChannelInterface	log
static final String	REFERENCE_PATH
static final String	SEPARATOR

Fields inherited from interface org.pentaho.di.trans.step.StepHelperInterface

ACTION_STATUS, FAILURE_METHOD_NOT_FOUND_RESPONSE, FAILURE_RESPONSE, STATUS, SUCCESS_RESPONSE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	BaseStepHelper()

Method Summary

Modifier and Type	Method	Description
protected String	getReferencePath(TransMeta transMeta, String directoryPath, String objectName, org.pentaho.di.core.ObjectLocationSpecificationMethod specificationMethod, String fileName)	Constructs the reference path for a transformation based on the provided directory path and name.
protected abstract org.json.simple.JSONObject	handleStepAction(String method, TransMeta transMeta, Map<String,String> queryParams)	Abstract method to be implemented by subclasses for handling step-specific actions.
boolean	isFailedResponse(org.json.simple.JSONObject response)	Utility method to check if a response indicates a failure.
org.json.simple.JSONObject	stepAction(String method, TransMeta transMeta, Map<String,String> queryParams)	Template method for executing a step action method.
protected org.json.simple.JSONObject	validateAndPutReferenceStatus(TransMeta transMeta, org.json.simple.JSONObject response, StepWithMappingMeta stepWithMappingMeta)	Validates the reference path of a StepWithMappingMeta instance and updates the response JSON object

Methods inherited from class java.lang.Object

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

Field Details

log

protected final org.pentaho.di.core.logging.LogChannelInterface log

IS_TRANS_REFERENCE

public static final String IS_TRANS_REFERENCE

See Also:

• Constant Field Values

IS_VALID_REFERENCE

public static final String IS_VALID_REFERENCE

See Also:

• Constant Field Values

REFERENCE_PATH

public static final String REFERENCE_PATH

See Also:

• Constant Field Values

SEPARATOR

public static final String SEPARATOR

See Also:

• Constant Field Values

Constructor Details

BaseStepHelper

protected BaseStepHelper()

Method Details

stepAction

public org.json.simple.JSONObject stepAction(String method,
 TransMeta transMeta,
 Map<String,String> queryParams)

Template method for executing a step action method. Handles response status and error logging. Subclasses should implement the `handleStepAction` method to provide step-specific logic.

Specified by:

stepAction in interface StepHelperInterface

Parameters:

method - The name of the method to execute.

transMeta - The transformation metadata associated with the step.

queryParams - A map of query parameters for the action.

Returns:

A JSON object containing the action status and any additional response data.

handleStepAction

protected abstract org.json.simple.JSONObject handleStepAction(String method,
 TransMeta transMeta,
 Map<String,String> queryParams)

Abstract method to be implemented by subclasses for handling step-specific actions.

Parameters:

method - The name of the method to execute.

transMeta - The transformation metadata associated with the step.

queryParams - A map of query parameters for the action.

Returns:

A JSON object containing the action status and any additional response data.

isFailedResponse

public boolean isFailedResponse(org.json.simple.JSONObject response)

Utility method to check if a response indicates a failure.

Parameters:

response - The JSON object containing the response data.

Returns:

True if the response indicates a failure, false otherwise.

getReferencePath

protected String getReferencePath(TransMeta transMeta,
 String directoryPath,
 String objectName,
 org.pentaho.di.core.ObjectLocationSpecificationMethod specificationMethod,
 String fileName)

Constructs the reference path for a transformation based on the provided directory path and name.

Parameters:

transMeta - The transformation metadata containing the step.

directoryPath - The directory path where the transformation or job is located.

objectName - The name of the transformation or job.

specificationMethod - The specification method used (e.g. REPOSITORY_BY_NAME, FILENAME).

fileName - The filename of the transformation or job (used if the specification method is FILENAME).

Returns:

The constructed reference path, or an empty string if neither directoryPath nor objectName is provided.

validateAndPutReferenceStatus

protected org.json.simple.JSONObject validateAndPutReferenceStatus(TransMeta transMeta,
 org.json.simple.JSONObject response,
 StepWithMappingMeta stepWithMappingMeta)

Validates the reference path of a StepWithMappingMeta instance and updates the response JSON object

Parameters:

transMeta - The transformation metadata containing the step.

stepWithMappingMeta - The StepWithMappingMeta instance containing the directory path and transformation name.

Returns:

A JSON object containing: - "referencePath": The full path to the referenced transformation, with environment variables substituted. - "isValidReference": A boolean indicating whether the referenced transformation is valid. - "isTransReference": A boolean indicating whether the reference is a transformation (always true for StepWithMapping).