/*
* Copyright 2012-2014 the original author or authors.
*
* 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 org.springframework.boot.cli.compiler;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import org.codehaus.groovy.ast.ASTNode;
import org.codehaus.groovy.ast.ClassCodeVisitorSupport;
import org.codehaus.groovy.ast.ClassHelper;
import org.codehaus.groovy.ast.ClassNode;
import org.codehaus.groovy.ast.ModuleNode;
import org.codehaus.groovy.ast.PropertyNode;
import org.codehaus.groovy.ast.expr.ClosureExpression;
import org.codehaus.groovy.ast.stmt.BlockStatement;
import org.codehaus.groovy.control.SourceUnit;
import org.codehaus.groovy.transform.ASTTransformation;
import org.springframework.core.annotation.Order;
/**
* {@link ASTTransformation} to resolve beans declarations inside application source
* files. Users only need to define a <code>beans{}</code> DSL element, and this
* transformation will remove it and make it accessible to the Spring application via an
* interface.
*
* @author Dave Syer
*/
@Order(GroovyBeansTransformation.ORDER)
public class GroovyBeansTransformation implements ASTTransformation {
public static final int ORDER = GrabMetadataTransformation.ORDER + 200;
@Override
public void visit(ASTNode[] nodes, SourceUnit source) {
for (ASTNode node : nodes) {
if (node instanceof ModuleNode) {
ModuleNode module = (ModuleNode) node;
for (ClassNode classNode : new ArrayList<ClassNode>(module.getClasses())) {
if (classNode.isScript()) {
classNode.visitContents(new ClassVisitor(source, classNode));
}
}
}
}
}
private class ClassVisitor extends ClassCodeVisitorSupport {
private static final String SOURCE_INTERFACE = "org.springframework.boot.BeanDefinitionLoader.GroovyBeanDefinitionSource";
private static final String BEANS = "beans";
private final SourceUnit source;
private final ClassNode classNode;
private boolean xformed = false;
public ClassVisitor(SourceUnit source, ClassNode classNode) {
this.source = source;
this.classNode = classNode;
}
@Override
protected SourceUnit getSourceUnit() {
return this.source;
}
@Override
public void visitBlockStatement(BlockStatement block) {
if (block.isEmpty() || this.xformed) {
return;
}
ClosureExpression closure = beans(block);
if (closure != null) {
// Add a marker interface to the current script
this.classNode.addInterface(ClassHelper.make(SOURCE_INTERFACE));
// Implement the interface by adding a public read-only property with the
// same name as the method in the interface (getBeans). Make it return the
// closure.
this.classNode.addProperty(new PropertyNode(BEANS, Modifier.PUBLIC
| Modifier.FINAL, ClassHelper.CLOSURE_TYPE
.getPlainNodeReference(), this.classNode, closure, null, null));
// Only do this once per class
this.xformed = true;
}
}
/**
* Extract a top-level <code>beans{}</code> closure from inside this block if
* there is one. Removes it from the block at the same time.
* @param block a block statement (class definition)
* @return a beans Closure if one can be found, null otherwise
*/
private ClosureExpression beans(BlockStatement block) {
return AstUtils.getClosure(block, BEANS, true);
}
}
}