001    /**
002     * Copyright (C) 2009-2011 the original author or authors.
003     * See the notice.md file distributed with this work for additional
004     * information regarding copyright ownership.
005     *
006     * Licensed under the Apache License, Version 2.0 (the "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    
019    package org.fusesource.restygwt.client.dispatcher;
020    
021    import org.fusesource.restygwt.client.cache.CacheKey;
022    import org.fusesource.restygwt.client.cache.QueueableCacheStorage;
023    import org.fusesource.restygwt.client.cache.UrlCacheKey;
024    import org.fusesource.restygwt.client.callback.CallbackFactory;
025    
026    import com.google.gwt.http.client.RequestBuilder;
027    
028    /**
029     * using a different caching 'algorithm' obeying the restful paradigm, i.e.
030     * the cache respects the lifecycle of a restful resource:
031     * <li>POST /model : will get the user responds into the cache using the location header for the key</li>
032     * <li>GET /model/{id} : will use the cached responds from cache if present</li>
033     * <li>PUT /model/{id} : will put the responds from the server into the cache. a conflict will delete the cache entry to allow
034     * a get to retrieve the up to date date</li>
035     * <li>DELETE /model/{id} : will also delete the resource in the cache</li>
036     *
037     * @author <a href="blog.mkristian.tk">Kristian</a>
038     */
039    public class RestfulCachingDispatcherFilter extends CachingDispatcherFilter {
040    
041        public RestfulCachingDispatcherFilter(QueueableCacheStorage cacheStorage,
042                CallbackFactory cf) {
043            super(cacheStorage, cf);
044        }
045        
046        protected CacheKey cacheKey(RequestBuilder builder){
047            if (RequestBuilder.GET.toString().equalsIgnoreCase(builder.getHTTPMethod())){
048                return new UrlCacheKey(builder);
049            }
050            else {
051                return null;
052            }
053        }
054    }