001    // Copyright 2007, 2008, 2009, 2011 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.tapestry5.internal.services;
016    
017    import org.apache.tapestry5.Link;
018    import org.apache.tapestry5.services.*;
019    
020    import java.util.Collection;
021    
022    /**
023     * Implements simple client-persistent properties. Most of the logic is delegated to an instance of {@link
024     * ClientPersistentFieldStorage}. This division of layer allows this service to be a true singleton, and a listener to
025     * the {@link LinkSource}, and allow per-request state to be isolated inside the other service.
026     */
027    public class ClientPersistentFieldStrategy implements PersistentFieldStrategy, LinkCreationListener2
028    {
029        private final ClientPersistentFieldStorage storage;
030    
031        public ClientPersistentFieldStrategy(ClientPersistentFieldStorage storage)
032        {
033            this.storage = storage;
034        }
035    
036        public Collection<PersistentFieldChange> gatherFieldChanges(String pageName)
037        {
038            return storage.gatherFieldChanges(pageName);
039        }
040    
041        public void postChange(String pageName, String componentId, String fieldName, Object newValue)
042        {
043            storage.postChange(pageName, componentId, fieldName, newValue);
044        }
045    
046        public void createdComponentEventLink(Link link, ComponentEventRequestParameters parameters)
047        {
048            storage.updateLink(link);
049        }
050    
051        public void createdPageRenderLink(Link link, PageRenderRequestParameters parameters)
052        {
053            storage.updateLink(link);
054        }
055    
056        public void discardChanges(String pageName)
057        {
058            storage.discardChanges(pageName);
059        }
060    }