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.l10n.ResourceLocalizer;
024    import org.apache.tapestry.web.WebContext;
025    import org.apache.tapestry.web.WebContextResource;
026    
027    /**
028     * All "context:" prefixed asset paths are interpreted relative to the web context (the web
029     * application's root folder).
030     * 
031     * @author Howard M. Lewis Ship
032     * @since 4.0
033     */
034    public class ContextAssetFactory implements AssetFactory
035    {
036        private String _contextPath;
037    
038        private AssetFactory _classpathAssetFactory;
039    
040        private WebContext _webContext;
041    
042        private ResourceLocalizer _localizer;
043    
044        public void setWebContext(WebContext webContext)
045        {
046            _webContext = webContext;
047        }
048    
049        public IAsset createAsset(Resource baseResource, String path, Locale locale, Location location)
050        {
051            // We always create a new asset relative to an existing resource; the type of resource
052            // will jive with the type of asset returned. Path may start with a leading slash, which
053            // yields an absolute, not relative, path to the resource.
054    
055            Resource assetResource = baseResource.getRelativeResource(path);
056    
057            // Here's the thing; In Tapestry 3.0 and earlier, you could specify
058            // library path like /org/apache/tapestry/contrib/Contrib.library. In the new scheme
059            // of things, that should be "classpath:/org/apache/tapestry/contrib/Contrib.library".
060            // But to keep a lot of things from breaking, we'll kludgely allow that here.
061    
062            if (assetResource.getResourceURL() == null && path.startsWith("/"))
063                return _classpathAssetFactory.createAbsoluteAsset(path, locale, location);
064    
065            Resource localized = _localizer.findLocalization(assetResource, locale);
066    
067            if (localized == null)
068                throw new ApplicationRuntimeException(AssetMessages.missingAsset(path, baseResource),
069                        location, null);
070    
071            return createAsset(localized, location);
072        }
073    
074        public IAsset createAbsoluteAsset(String path, Locale locale, Location location)
075        {
076            Resource base = new WebContextResource(_webContext, path);
077            Resource localized = _localizer.findLocalization(base, locale);
078    
079            if (localized == null)
080                throw new ApplicationRuntimeException(AssetMessages.missingContextResource(path),
081                        location, null);
082    
083            return createAsset(localized, location);
084        }
085    
086        public IAsset createAsset(Resource resource, Location location)
087        {
088            return new ContextAsset(_contextPath, resource, location);
089        }
090    
091        public void setContextPath(String contextPath)
092        {
093            _contextPath = contextPath;
094        }
095    
096        public void setClasspathAssetFactory(AssetFactory classpathAssetFactory)
097        {
098            _classpathAssetFactory = classpathAssetFactory;
099        }
100    
101        public void setLocalizer(ResourceLocalizer localizer)
102        {
103            _localizer = localizer;
104        }
105    }