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Groovy: A powerful, dynamic language for the JVM
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 groovy.transform.builder;
import org.codehaus.groovy.ast.AnnotatedNode;
import org.codehaus.groovy.ast.AnnotationNode;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.FieldNode;
import org.codehaus.groovy.ast.Parameter;
import org.codehaus.groovy.transform.AbstractASTTransformation;
import org.codehaus.groovy.transform.BuilderASTTransformation;
import org.objectweb.asm.Opcodes;
import java.util.ArrayList;
import java.util.List;
import static org.codehaus.groovy.ast.tools.GeneralUtils.assignX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.block;
import static org.codehaus.groovy.ast.tools.GeneralUtils.fieldX;
import static org.codehaus.groovy.ast.tools.GeneralUtils.getInstancePropertyFields;
import static org.codehaus.groovy.ast.tools.GeneralUtils.param;
import static org.codehaus.groovy.ast.tools.GeneralUtils.params;
import static org.codehaus.groovy.ast.tools.GeneralUtils.returnS;
import static org.codehaus.groovy.ast.tools.GeneralUtils.stmt;
import static org.codehaus.groovy.ast.tools.GeneralUtils.varX;
import static org.codehaus.groovy.ast.tools.GenericsUtils.newClass;
import static org.codehaus.groovy.transform.BuilderASTTransformation.NO_EXCEPTIONS;
/**
* This strategy is used with the {@link Builder} AST transform to modify your Groovy objects so that the
* setter methods for properties return the original object, thus allowing chained usage of the setters.
*
* You use it as follows:
*
* import groovy.transform.builder.*
*
* {@code @Builder}(builderStrategy=SimpleStrategy)
* class Person {
* String firstName
* String lastName
* int age
* }
* def person = new Person().setFirstName("Robert").setLastName("Lewandowski").setAge(21)
* assert person.firstName == "Robert"
* assert person.lastName == "Lewandowski"
* assert person.age == 21
*
* The {@code prefix} annotation attribute can be used to create setters with a different naming convention, e.g. with the prefix set to the empty String, you would use your setters as follows:
*
* def p1 = new Person().firstName("Robert").lastName("Lewandowski").age(21)
*
* or using a prefix of 'with':
*
* def p2 = new Person().withFirstName("Robert").withLastName("Lewandowski").withAge(21)
*
* When using the default prefix of "set", Groovy's normal setters will be replaced by the chained versions. When using
* a custom prefix, Groovy's unchained setters will still be available for use in the normal unchained fashion.
*
* The other annotation attributes for the {@code @Builder} transform for configuring the building process aren't applicable for this strategy.
*
* @author Paul King
*/
public class SimpleStrategy extends BuilderASTTransformation.AbstractBuilderStrategy {
public void build(BuilderASTTransformation transform, AnnotatedNode annotatedNode, AnnotationNode anno) {
if (!(annotatedNode instanceof ClassNode)) {
transform.addError("Error during " + BuilderASTTransformation.MY_TYPE_NAME + " processing: building for " +
annotatedNode.getClass().getSimpleName() + " not supported by " + getClass().getSimpleName(), annotatedNode);
return;
}
ClassNode buildee = (ClassNode) annotatedNode;
if (unsupportedAttribute(transform, anno, "builderClassName")) return;
if (unsupportedAttribute(transform, anno, "buildMethodName")) return;
if (unsupportedAttribute(transform, anno, "builderMethodName")) return;
if (unsupportedAttribute(transform, anno, "forClass")) return;
List excludes = new ArrayList();
List includes = new ArrayList();
if (!getIncludeExclude(transform, anno, buildee, excludes, includes)) return;
String prefix = transform.getMemberStringValue(anno, "prefix", "set");
List fields = getInstancePropertyFields(buildee);
for (String name : includes) {
checkKnownField(transform, anno, name, fields);
}
for (FieldNode field : fields) {
String fieldName = field.getName();
if (!AbstractASTTransformation.shouldSkip(fieldName, excludes, includes)) {
String methodName = getSetterName(prefix, fieldName);
Parameter parameter = param(field.getType(), fieldName);
buildee.addMethod(methodName, Opcodes.ACC_PUBLIC, newClass(buildee), params(parameter), NO_EXCEPTIONS, block(
stmt(assignX(fieldX(field), varX(parameter))),
returnS(varX("this")))
);
}
}
}
}