// Copyright 2006, 2007, 2008, 2010 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.tapestry5.internal.transform;
import org.apache.tapestry5.ComponentResources;
import org.apache.tapestry5.annotations.InjectPage;
import org.apache.tapestry5.ioc.internal.util.InternalUtils;
import org.apache.tapestry5.ioc.services.FieldValueConduit;
import org.apache.tapestry5.model.MutableComponentModel;
import org.apache.tapestry5.runtime.PageLifecycleAdapter;
import org.apache.tapestry5.services.ClassTransformation;
import org.apache.tapestry5.services.ComponentClassResolver;
import org.apache.tapestry5.services.ComponentClassTransformWorker;
import org.apache.tapestry5.services.ComponentSource;
import org.apache.tapestry5.services.ComponentValueProvider;
import org.apache.tapestry5.services.TransformField;
/**
* Peforms transformations that allow pages to be injected into components.
*
* @see org.apache.tapestry5.annotations.InjectPage
*/
public class InjectPageWorker implements ComponentClassTransformWorker
{
private final class InjectedPageConduit extends ReadOnlyFieldValueConduit
{
private final String injectedPageName;
private Object page;
private InjectedPageConduit(ComponentResources resources, String fieldName,
String injectedPageName)
{
super(resources, fieldName);
this.injectedPageName = injectedPageName;
resources.addPageLifecycleListener(new PageLifecycleAdapter()
{
@Override
public void containingPageDidDetach()
{
page = null;
}
});
}
public Object get()
{
if (page == null)
page = componentSource.getPage(injectedPageName);
return page;
}
}
private final ComponentSource componentSource;
private final ComponentClassResolver resolver;
public InjectPageWorker(ComponentSource componentSource, ComponentClassResolver resolver)
{
this.componentSource = componentSource;
this.resolver = resolver;
}
public void transform(ClassTransformation transformation, MutableComponentModel model)
{
for (TransformField field : transformation.matchFieldsWithAnnotation(InjectPage.class))
{
addInjectedPage(field);
}
}
private void addInjectedPage(TransformField field)
{
InjectPage annotation = field.getAnnotation(InjectPage.class);
field.claim(annotation);
String pageName = annotation.value();
final String fieldName = field.getName();
final String injectedPageName = InternalUtils.isBlank(pageName) ? resolver
.resolvePageClassNameToPageName(field.getType()) : pageName;
ComponentValueProvider<FieldValueConduit> provider = new ComponentValueProvider<FieldValueConduit>()
{
public FieldValueConduit get(ComponentResources resources)
{
return new InjectedPageConduit(resources, fieldName, injectedPageName);
}
};
field.replaceAccess(provider);
}
}