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.record; 016 017 import org.apache.hivemind.util.Defense; 018 import org.apache.tapestry.engine.ServiceEncoding; 019 import org.apache.tapestry.web.WebRequest; 020 021 import java.util.*; 022 023 /** 024 * Service tapestry.persist.ClientPropertyPersistenceStrategy. Encodes persistent page properties on 025 * the client as query parameters. 026 * <p> 027 * Uses the threaded model. 028 * 029 * @author Howard M. Lewis Ship 030 * @since 4.0 031 * @see org.apache.tapestry.engine.ILink 032 */ 033 public class ClientPropertyPersistenceStrategy implements PropertyPersistenceStrategy 034 { 035 /** 036 * Keyed on page name (String), values are 037 * {@link org.apache.tapestry.record.PersistentPropertyData}. 038 */ 039 protected final Map _data = new LinkedHashMap(); 040 041 protected PersistentPropertyDataEncoder _encoder; 042 043 protected WebRequest _request; 044 045 protected ClientPropertyPersistenceScope _scope; 046 047 /** 048 * Initializer for this service, invoked every time a service instance is created. This 049 * initializer pulls out of the request and query parameters whose prefix is "client:" and 050 * expects them to be encoded {@link PersistentPropertyData}, which are stored internally. 051 * Because the service model is threaded, this information is specific to a single request, and 052 * will be discarded at the end of the request. 053 */ 054 055 public void initializeService() 056 { 057 List names = _request.getParameterNames(); 058 Iterator i = names.iterator(); 059 while (i.hasNext()) 060 { 061 String name = (String) i.next(); 062 063 if (!_scope.isParameterForScope(name)) 064 continue; 065 066 String pageName = _scope.extractPageName(name); 067 068 String encoded = _request.getParameterValue(name); 069 070 PersistentPropertyData data = new PersistentPropertyData(_encoder); 071 data.storeEncoded(encoded); 072 073 _data.put(pageName, data); 074 } 075 } 076 077 public void store(String pageName, String idPath, String propertyName, Object newValue) 078 { 079 PersistentPropertyData data = (PersistentPropertyData) _data.get(pageName); 080 if (data == null) 081 { 082 data = new PersistentPropertyData(_encoder); 083 _data.put(pageName, data); 084 } 085 086 data.store(idPath, propertyName, newValue); 087 } 088 089 public Collection getStoredChanges(String pageName) 090 { 091 PersistentPropertyData data = (PersistentPropertyData) _data.get(pageName); 092 093 if (data == null) 094 return Collections.EMPTY_LIST; 095 096 return data.getPageChanges(); 097 } 098 099 public void discardStoredChanges(String pageName) 100 { 101 _data.remove(pageName); 102 } 103 104 public void addParametersForPersistentProperties(ServiceEncoding encoding, boolean post) 105 { 106 Defense.notNull(encoding, "encoding"); 107 108 Iterator i = _data.entrySet().iterator(); 109 while (i.hasNext()) 110 { 111 Map.Entry e = (Map.Entry) i.next(); 112 113 String pageName = (String) e.getKey(); 114 PersistentPropertyData data = (PersistentPropertyData) e.getValue(); 115 116 ClientPropertyPersistenceScope scope = getScope(); 117 118 if (scope.shouldEncodeState(encoding, pageName, data)) 119 { 120 String parameterName = _scope.constructParameterName(pageName); 121 encoding.setParameterValue(parameterName, data.getEncoded()); 122 } 123 } 124 } 125 126 public void setRequest(WebRequest request) 127 { 128 _request = request; 129 } 130 131 public ClientPropertyPersistenceScope getScope() 132 { 133 return _scope; 134 } 135 136 public void setScope(ClientPropertyPersistenceScope scope) 137 { 138 _scope = scope; 139 } 140 141 public void setEncoder(PersistentPropertyDataEncoder encoder) 142 { 143 _encoder = encoder; 144 } 145 }