// Copyright 2006, 2007 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 org.apache.tapestry.Asset;
import org.apache.tapestry.internal.events.InvalidationListener;
import org.apache.tapestry.ioc.Resource;
import org.apache.tapestry.ioc.internal.util.ClasspathResource;
import static org.apache.tapestry.ioc.internal.util.CollectionFactory.newConcurrentMap;
import org.apache.tapestry.services.AssetFactory;
import org.apache.tapestry.services.ClasspathAssetAliasManager;
import java.util.Map;
/**
* Generates Assets for files on the classpath. Caches generated client URLs internally, and clears
* that cache when notified to do so by the {@link ResourceCache}.
*
* @see AssetDispatcher
*/
public class ClasspathAssetFactory implements AssetFactory, InvalidationListener
{
private final ResourceCache _cache;
private final ClasspathAssetAliasManager _aliasManager;
private final Map<Resource, String> _resourceToClientURL = newConcurrentMap();
public ClasspathAssetFactory(final ResourceCache cache,
final ClasspathAssetAliasManager aliasManager)
{
_cache = cache;
_aliasManager = aliasManager;
}
public void objectWasInvalidated()
{
_resourceToClientURL.clear();
}
private String clientURL(Resource resource)
{
String clientURL = _resourceToClientURL.get(resource);
if (clientURL == null)
{
clientURL = buildClientURL(resource);
_resourceToClientURL.put(resource, clientURL);
}
return clientURL;
}
private String buildClientURL(Resource resource)
{
boolean requiresDigest = _cache.requiresDigest(resource);
String path = resource.getPath();
if (requiresDigest)
{
// Resources with extensions go from foo/bar/baz.txt --> foo/bar/baz.CHECKSUM.txt
int lastdotx = path.lastIndexOf('.');
String revisedPath = path.substring(0, lastdotx + 1) + _cache.getDigest(resource)
+ path.substring(lastdotx);
return _aliasManager.toClientURL(revisedPath);
}
return _aliasManager.toClientURL(path);
}
public Asset createAsset(final Resource resource)
{
// TODO: Assets will eventually have a kind of symbolic link used
// to shorten the path. Some assets may need to have a checksum embedded
// in the path as well.
return new Asset()
{
public Resource getResource()
{
return resource;
}
public String toClientURL()
{
return clientURL(resource);
}
@Override
public String toString()
{
return toClientURL();
}
};
}
public Resource getRootResource()
{
return new ClasspathResource("");
}
}