core/org.eclipse.smila.processing/code/src/org/eclipse/smila/processing/WorkflowProcessor.java

/*******************************************************************************
 * Copyright (c) 2008, 2009 empolis GmbH and brox IT Solutions GmbH. All rights reserved. This program and the
 * accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: Juergen Schumacher (empolis GmbH) - initial API and implementation
 *******************************************************************************/

package org.eclipse.smila.processing;

import java.util.List;

import org.eclipse.smila.blackboard.Blackboard;
import org.eclipse.smila.datamodel.AnyMap;

/**
 * Interface of WorkflowProcessors. A workflow orchestrates a set of SMILA pipelets (or other components) to process
 * SMILA records. It may use deliberate workflow definition languages, e.g. BPEL.
 * 
 * @author jschumacher
 * 
 */
public interface WorkflowProcessor {

  /**
   * namespace of SMILA BPEL process names.
   */
  String NAMESPACE_PROCESSOR = "http://www.eclipse.org/smila/processor";

  /** key in workflow definitions for the name of the workflow. */
  String WORKFLOW_NAME = "name";

  /** key in workflow definitions for the timestamp of the workflow, set automatically when defining the workflow. */
  String WORKFLOW_TIMESTAMP = "timestamp";

  /** key in workflow definitions for the definition of the workflow. */
  String WORKFLOW_DEFINITION = "definition";

  /**
   * key in workflow definitions for the readOnly flag, set in {@link #getWorkflowDefinition(String)} results for
   * predefined workflows.
   */
  String WORKFLOW_READONLY = "readOnly";

  /**
   * process records on Blackboard service.
   * 
   * @param workflowName
   *          name of workflow to execute on Ids
   * @param blackboard
   *          blackboard to use for processing
   * @param recordIds
   *          Ids of records to process.
   * @return Ids of result records.
   * @throws ProcessingException
   *           error during processing.
   */
  String[] process(String workflowName, Blackboard blackboard, String[] recordIds) throws ProcessingException;

  /**
   * get the names of the currently active workflows.
   * 
   * @return names of workflows.
   */
  List<String> getWorkflowNames();

  /**
   * get the definition for a given workflow name.
   * 
   * @param workflowName
   *          The workflow name
   * @return the any object with the definition
   * @throws ProcessingException
   *           error reading the definition.
   */
  AnyMap getWorkflowDefinition(String workflowName) throws ProcessingException;

  /**
   * @param workflowName
   *          The workflow name
   * @param workflowDefinition
   *          contains the workflow to add/update and deploy
   * @throws ProcessingException
   *           error during deploy
   */
  void setWorkflowDefinition(String workflowName, AnyMap workflowDefinition) throws ProcessingException;

  /**
   * @param workflowName
   *          The workflow name to delete and undeploy
   * @throws ProcessingException
   *           error during undeploy
   */
  void deleteWorkflowDefinition(String workflowName) throws ProcessingException;

  /**
   * reload the workflow definition from persistence and deploy it, or undeploy it. This can be called to notify the
   * processor that the definition has been changed by someone else, e.g. another cluster node.
   * 
   * @param workflowName
   *          the name of the workflow to reload.
   * @param isDeleted
   *          true to undeploy workflow locally, false to deploy the currently persisted version.
   * @throws ProcessingException
   *           if the workflow could not be reloaded for any reason.
   */
  void synchronizeWorkflowDefinition(String workflowName, boolean isDeleted) throws ProcessingException;

}