// 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 static org.apache.tapestry.ioc.internal.util.CollectionFactory.newMap;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newThreadSafeMap;
import static org.apache.tapestry.ioc.internal.util.Defense.notBlank;
import static org.apache.tapestry.ioc.internal.util.Defense.notNull;
import java.util.Locale;
import java.util.Map;
import org.apache.tapestry.Asset;
import org.apache.tapestry.ioc.Resource;
import org.apache.tapestry.ioc.util.StrategyRegistry;
import org.apache.tapestry.services.AssetFactory;
import org.apache.tapestry.services.AssetSource;
/**
* Implementation of {@link AssetSource} available as service:tapestry.AssetSource or
* infrastructure:AssetSource.
*/
public class AssetSourceImpl implements AssetSource
{
private final StrategyRegistry<AssetFactory> _registry;
private final Map<String, Resource> _prefixToRootResource = newMap();
private final Map<Resource, Asset> _cache = newThreadSafeMap();
public AssetSourceImpl(Map<String, AssetFactory> configuration)
{
Map<Class, AssetFactory> byResourceClass = newMap();
for (Map.Entry<String, AssetFactory> e : configuration.entrySet())
{
String prefix = e.getKey();
AssetFactory factory = e.getValue();
Resource rootResource = factory.getRootResource();
byResourceClass.put(rootResource.getClass(), factory);
_prefixToRootResource.put(prefix, rootResource);
}
_registry = StrategyRegistry.newInstance(AssetFactory.class, byResourceClass);
}
public Asset getClasspathAsset(String path, Locale locale)
{
Resource baseResource = _prefixToRootResource.get("classpath");
return findAsset(baseResource, path, locale);
}
public Asset findAsset(Resource baseResource, String path, Locale locale)
{
notNull(baseResource, "baseResource");
notBlank(path, "path");
notNull(locale, "locale");
int colonx = path.indexOf(':');
if (colonx < 0)
return findRelativeAsset(baseResource, path, locale);
String prefix = path.substring(0, colonx);
Resource rootResource = _prefixToRootResource.get(prefix);
if (rootResource == null)
throw new IllegalArgumentException(ServicesMessages.unknownAssetPrefix(path));
return findRelativeAsset(rootResource, path.substring(colonx + 1), locale);
}
private Asset findRelativeAsset(Resource baseResource, String path, Locale locale)
{
Resource unlocalized = baseResource.forFile(path);
Resource localized = unlocalized.forLocale(locale);
if (localized == null)
throw new RuntimeException(ServicesMessages.assetDoesNotExist(unlocalized));
return getAssetForResource(localized);
}
private Asset getAssetForResource(Resource resource)
{
Asset result = _cache.get(resource);
if (result == null)
{
result = createAssetFromResource(resource);
_cache.put(resource, result);
}
return result;
}
private Asset createAssetFromResource(Resource resource)
{
// The class of the resource is derived from the class of the base resource.
// So we can then use the class of the resource as a key to locate the correct asset
// factory.
Class resourceClass = resource.getClass();
AssetFactory factory = _registry.get(resourceClass);
return factory.createAsset(resource);
}
}