// Copyright 2006 The Apache Software Foundation
//
// 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.apache.tapestry.internal.services;
import java.util.List;
import org.apache.tapestry.annotations.Mixin;
import org.apache.tapestry.ioc.internal.util.InternalUtils;
import org.apache.tapestry.model.MutableComponentModel;
import org.apache.tapestry.services.ClassTransformation;
import org.apache.tapestry.services.ComponentClassResolver;
import org.apache.tapestry.services.ComponentClassTransformWorker;
import org.apache.tapestry.services.TransformConstants;
/**
* Supports the {@link Mixin} annotation, which allows a mixin to be part of the implementation of a
* component. The annotation is applied to a field, which will become read-only, and contain a
* reference to the mixin instance.
*/
public class MixinWorker implements ComponentClassTransformWorker
{
private final ComponentClassResolver _resolver;
public MixinWorker(final ComponentClassResolver resolver)
{
_resolver = resolver;
}
public void transform(ClassTransformation transformation, MutableComponentModel model)
{
List<String> fields = transformation.findFieldsWithAnnotation(Mixin.class);
for (String fieldName : fields)
{
Mixin annotation = transformation.getFieldAnnotation(fieldName, Mixin.class);
String mixinType = annotation.value();
String fieldType = transformation.getFieldType(fieldName);
String mixinClassName = InternalUtils.isBlank(mixinType) ? fieldType : _resolver
.resolveMixinTypeToClassName(mixinType);
model.addMixinClassName(mixinClassName);
transformation.makeReadOnly(fieldName);
String body = String.format(
"%s = (%s) %s.getMixinByClassName(\"%s\");",
fieldName,
fieldType,
transformation.getResourcesFieldName(),
mixinClassName);
transformation
.extendMethod(TransformConstants.CONTAINING_PAGE_DID_LOAD_SIGNATURE, body);
transformation.claimField(fieldName, annotation);
}
}
}