RulesExecutor.java

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 *
 * Pentaho Data Integration
 *
 * Copyright (C) 2002-2013 by Pentaho : http://www.pentaho.com
 *
 *******************************************************************************
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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package org.pentaho.di.trans.steps.rules;

import java.util.Arrays;

import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.core.exception.KettleStepException;
import org.pentaho.di.trans.Trans;
import org.pentaho.di.trans.TransMeta;
import org.pentaho.di.trans.step.BaseStep;
import org.pentaho.di.trans.step.StepDataInterface;
import org.pentaho.di.trans.step.StepInterface;
import org.pentaho.di.trans.step.StepMeta;
import org.pentaho.di.trans.step.StepMetaInterface;
import org.pentaho.di.trans.steps.rules.Rules.Column;

/**
 * This Transformation Step allows a user to execute a rule set against an individual rule or a collection of rules.
 *
 * Additional columns can be added to the output from the rules and these (of course) can be used for routing if
 * desired.
 *
 * @author cboyden
 *
 */

public class RulesExecutor extends BaseStep implements StepInterface {
  // private static Class<?> PKG = Rules.class; // for i18n purposes

  private RulesExecutorMeta meta;

  private RulesExecutorData data;

  public RulesExecutor( StepMeta stepMeta, StepDataInterface stepDataInterface, int copyNr, TransMeta transMeta,
    Trans trans ) {
    super( stepMeta, stepDataInterface, copyNr, transMeta, trans );
  }

  public boolean init( StepMetaInterface smi, StepDataInterface sdi ) {

    meta = (RulesExecutorMeta) smi;
    data = (RulesExecutorData) sdi;

    if ( super.init( smi, sdi ) ) {
      return true;
    }
    return false;
  }

  public boolean runtimeInit() throws KettleStepException {
    data.setOutputRowMeta( getInputRowMeta().clone() );
    meta.getFields( data.getOutputRowMeta(), getStepname(), null, null, this, repository, metaStore );

    data.setRuleFilePath( meta.getRuleFile() );
    data.setRuleString( meta.getRuleDefinition() );

    data.initializeRules();
    data.initializeColumns( getInputRowMeta() );

    return true;
  }

  public void dispose( StepMetaInterface smi, StepDataInterface sdi ) {
    meta = (RulesExecutorMeta) smi;
    data = (RulesExecutorData) sdi;

    super.dispose( smi, sdi );
  }

  public boolean processRow( StepMetaInterface smi, StepDataInterface sdi ) throws KettleException {
    meta = (RulesExecutorMeta) smi;
    data = (RulesExecutorData) sdi;

    Object[] r = getRow(); // get row, set busy!
    if ( r == null ) { // no more input to be expected...

      data.shutdown();
      setOutputDone();
      return false;
    }

    if ( first ) {
      if ( !runtimeInit() ) {
        return false;
      }

      first = false;
    }

    // Load the column objects
    data.loadRow( r );

    data.execute();

    Object[] outputRow;
    int beginOutputRowFill = 0;

    String[] expectedResults = meta.getExpectedResultList();

    if ( meta.isKeepInputFields() ) {
      int inputRowSize = getInputRowMeta().size();
      outputRow = Arrays.copyOf( r, inputRowSize + expectedResults.length );
      beginOutputRowFill = inputRowSize;
    } else {
      outputRow = new Object[expectedResults.length];
    }

    Column result = null;
    for ( int i = 0; i < expectedResults.length; i++ ) {
      result = (Column) data.fetchResult( expectedResults[i] );
      outputRow[i + beginOutputRowFill] = result == null ? null : result.getPayload();
    }

    putRow( data.getOutputRowMeta(), outputRow );

    return true;
  }
}