001/*
002 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
003 *
004 * Project and contact information: http://www.cascading.org/
005 *
006 * This file is part of the Cascading project.
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021package cascading.flow.planner.rule.transformer;
022
023import cascading.flow.planner.iso.expression.ExpressionGraph;
024import cascading.flow.planner.iso.transformer.ReplaceGraphFactoryBasedTransformer;
025import cascading.flow.planner.rule.PlanPhase;
026import cascading.flow.planner.rule.RuleExpression;
027import cascading.flow.planner.rule.RuleTransformer;
028
029/**
030 * RuleTransformer that uses the supplied expression to fetch the FlowElement to replace.
031 * The replacement FlowElement is created using the supplied factory.
032 */
033public class RuleReplaceFactoryBasedTransformer extends RuleTransformer
034  {
035  public RuleReplaceFactoryBasedTransformer( PlanPhase phase, RuleExpression ruleExpression, String factoryName )
036    {
037    super( phase, ruleExpression );
038
039    ExpressionGraph matchExpression = ruleExpression.getMatchExpression();
040
041    if( subGraphTransformer != null )
042      graphTransformer = new ReplaceGraphFactoryBasedTransformer( subGraphTransformer, matchExpression, factoryName );
043    else if( contractedTransformer != null )
044      graphTransformer = new ReplaceGraphFactoryBasedTransformer( contractedTransformer, matchExpression, factoryName );
045    else
046      graphTransformer = new ReplaceGraphFactoryBasedTransformer( matchExpression, factoryName );
047    }
048  }