// Copyright 2007, 2008, 2009 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.Asset;
import org.apache.tapestry5.ComponentResources;
import org.apache.tapestry5.annotations.SetupRender;
import org.apache.tapestry5.internal.services.ComponentResourcesOperation;
import org.apache.tapestry5.ioc.Resource;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.services.SymbolSource;
import org.apache.tapestry5.model.MutableComponentModel;
import org.apache.tapestry5.services.AssetSource;
import org.apache.tapestry5.services.ClassTransformation;
import org.apache.tapestry5.services.ComponentClassTransformWorker;
import org.apache.tapestry5.services.TransformConstants;
import java.util.List;
import java.util.Locale;
/**
* Base class for workers that automatically inlcude assets in the page (via methods on {@link
* org.apache.tapestry5.RenderSupport}).
*/
public abstract class AbstractIncludeAssetWorker implements ComponentClassTransformWorker
{
private final AssetSource assetSource;
private final SymbolSource symbolSource;
public AbstractIncludeAssetWorker(AssetSource assetSource, SymbolSource symbolSource)
{
this.assetSource = assetSource;
this.symbolSource = symbolSource;
}
/**
* Expands symbols in the path, then adds an operation into the setup render phase of the component. Ultimately,
* {@link #handleAsset(org.apache.tapestry5.Asset)} will be invoked for each asset (dervied from assetPaths).
*
* @param transformation transformation process for component
* @param model component model for component
* @param assetPaths raw paths to be converted to assets
*/
protected final void addOperationForAssetPaths(ClassTransformation transformation,
MutableComponentModel model, String[] assetPaths)
{
final Resource baseResource = model.getBaseResource();
final List<String> paths = CollectionFactory.newList();
for (String value : assetPaths)
{
String expanded = symbolSource.expandSymbols(value);
paths.add(expanded);
}
ComponentResourcesOperation op = new ComponentResourcesOperation()
{
// Remember that ONE instances of this op will be injected into EVERY instance
// of the component ... that means that we can't do any aggresive caching
// inside the operation (the operation must be threadsafe).
public void perform(ComponentResources resources)
{
Locale locale = resources.getLocale();
for (String assetPath : paths)
{
Asset asset = assetSource.getAsset(baseResource, assetPath, locale);
handleAsset(asset);
}
}
};
String opFieldName = transformation.addInjectedField(ComponentResourcesOperation.class, "operation", op);
String resourcesName = transformation.getResourcesFieldName();
String body = String.format("%s.perform(%s);", opFieldName, resourcesName);
// This is what I like about this approach; the injected body is tiny. The downside is that
// the object that gets injected is hard to test, hard enough that we'll just concentrate on
// the integration test, thank you.
transformation.extendMethod(TransformConstants.SETUP_RENDER_SIGNATURE, body);
model.addRenderPhase(SetupRender.class);
}
/**
* Invoked, from the component's setup render phase, for each asset. This method must be threadsafe. Most
* implementation pass the asset to a particular method of {@link org.apache.tapestry5.RenderSupport}.
*
* @param asset to be processed
*/
protected abstract void handleAsset(Asset asset);
}