com.blazebit.persistence.parser.AliasReplacementVisitor Maven / Gradle / Ivy
/*
* Copyright 2014 - 2021 Blazebit.
*
* 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
* limitations under the License.
*/
package com.blazebit.persistence.parser;
import com.blazebit.persistence.parser.expression.Expression;
import com.blazebit.persistence.parser.expression.ExpressionCopyContext;
import com.blazebit.persistence.parser.expression.InplaceModificationResultVisitorAdapter;
import com.blazebit.persistence.parser.expression.PathElementExpression;
import com.blazebit.persistence.parser.expression.PathExpression;
import com.blazebit.persistence.parser.expression.PropertyExpression;
import com.blazebit.persistence.parser.util.ExpressionUtils;
import java.util.List;
/**
*
* @author Christian Beikov
* @author Moritz Becker
* @since 1.0.0
*/
public class AliasReplacementVisitor extends InplaceModificationResultVisitorAdapter {
private final Expression substitute;
private final String alias;
public AliasReplacementVisitor(Expression substitute, String alias) {
this.substitute = substitute;
this.alias = alias;
}
@Override
public Expression visit(PathExpression expression) {
List expressions = expression.getExpressions();
int size = expressions.size();
if (size == 1) {
PathElementExpression elementExpression = expressions.get(0);
if (elementExpression instanceof PropertyExpression) {
if (alias.equals(((PropertyExpression) elementExpression).getProperty())) {
Expression newExpression = substitute.copy(ExpressionCopyContext.EMPTY);
if (newExpression instanceof PathExpression) {
PathExpression newPathExpression = (PathExpression) newExpression;
newPathExpression.setUsedInCollectionFunction(expression.isUsedInCollectionFunction());
newPathExpression.setCollectionQualifiedPath(expression.isCollectionQualifiedPath());
}
return newExpression;
}
}
} else {
PathExpression leftMost = ExpressionUtils.getLeftMostPathExpression(expression);
if (leftMost.getExpressions().get(0) instanceof PropertyExpression && alias.equals(((PropertyExpression) leftMost.getExpressions().get(0)).getProperty())) {
if (substitute instanceof PathExpression) {
leftMost.getExpressions().remove(0);
leftMost.getExpressions().addAll(0, ((PathExpression) substitute).getExpressions());
} else {
leftMost.getExpressions().set(0, (PathElementExpression) substitute);
}
}
}
return expression;
}
}