001    // Copyright 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.asset;
016    
017    import java.util.Locale;
018    
019    import org.apache.hivemind.ApplicationRuntimeException;
020    import org.apache.hivemind.Location;
021    import org.apache.hivemind.Resource;
022    import org.apache.tapestry.IAsset;
023    import org.apache.tapestry.web.WebContext;
024    import org.apache.tapestry.web.WebContextResource;
025    
026    /**
027     * All "context:" prefixed asset paths are interpreted relative to the web context (the web
028     * application's root folder).
029     * 
030     * @author Howard M. Lewis Ship
031     * @since 4.0
032     */
033    public class ContextAssetFactory implements AssetFactory
034    {
035        private String _contextPath;
036    
037        private AssetFactory _classpathAssetFactory;
038    
039        private WebContext _webContext;
040    
041        public void setWebContext(WebContext webContext)
042        {
043            _webContext = webContext;
044        }
045    
046        public IAsset createAsset(Resource baseResource, String path, Locale locale, Location location)
047        {
048            // We always create a new asset relative to an existing resource; the type of resource
049            // will jive with the type of asset returned. Path may start with a leading slash, which
050            // yields an absolute, not relative, path to the resource.
051    
052            Resource assetResource = baseResource.getRelativeResource(path);
053    
054            // Here's the thing; In Tapestry 3.0 and earlier, you could specify
055            // library path like /org/apache/tapestry/contrib/Contrib.library. In the new scheme
056            // of things, that should be "classpath:/org/apache/tapestry/contrib/Contrib.library".
057            // But to keep a lot of things from breaking, we'll kludgely allow that here.
058    
059            if (assetResource.getResourceURL() == null && path.startsWith("/"))
060                return _classpathAssetFactory.createAbsoluteAsset(path, locale, location);
061    
062            Resource localized = assetResource.getLocalization(locale);
063    
064            if (localized == null)
065                throw new ApplicationRuntimeException(AssetMessages.missingAsset(path, baseResource),
066                        location, null);
067    
068            return createAsset(localized, location);
069        }
070    
071        public IAsset createAbsoluteAsset(String path, Locale locale, Location location)
072        {
073            Resource base = new WebContextResource(_webContext, path);
074            Resource localized = base.getLocalization(locale);
075    
076            if (localized == null)
077                throw new ApplicationRuntimeException(AssetMessages.missingContextResource(path),
078                        location, null);
079    
080            return createAsset(localized, location);
081        }
082    
083        public IAsset createAsset(Resource resource, Location location)
084        {
085            return new ContextAsset(_contextPath, resource, location);
086        }
087    
088        public void setContextPath(String contextPath)
089        {
090            _contextPath = contextPath;
091        }
092    
093        public void setClasspathAssetFactory(AssetFactory classpathAssetFactory)
094        {
095            _classpathAssetFactory = classpathAssetFactory;
096        }
097    }