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.services.impl;
016    
017    import java.util.ArrayList;
018    import java.util.HashMap;
019    import java.util.List;
020    import java.util.Locale;
021    import java.util.Map;
022    
023    import org.apache.hivemind.Resource;
024    import org.apache.hivemind.lib.chain.ChainBuilder;
025    import org.apache.tapestry.IComponent;
026    import org.apache.tapestry.INamespace;
027    import org.apache.tapestry.engine.IPropertySource;
028    import org.apache.tapestry.event.ResetEventListener;
029    import org.apache.tapestry.services.ComponentPropertySource;
030    import org.apache.tapestry.spec.IComponentSpecification;
031    import org.apache.tapestry.util.PropertyHolderPropertySource;
032    
033    /**
034     * Implementation of tapestry.props.ComponentPropertySource.
035     * <p>
036     * TODO: Figure out a testing strategy for this beast!
037     * 
038     * @author Howard M. Lewis Ship
039     * @since 4.0
040     */
041    public class ComponentPropertySourceImpl implements ComponentPropertySource, ResetEventListener
042    {
043        private IPropertySource _globalProperties;
044    
045        private ChainBuilder _chainBuilder;
046    
047        private Map _componentSources = new HashMap();
048    
049        private Map _localizedComponentSources = new HashMap();
050    
051        private Map _namespaceSources = new HashMap();
052    
053        private Map _localizedNamespaceSources = new HashMap();
054    
055        public synchronized void resetEventDidOccur()
056        {
057            _componentSources.clear();
058            _localizedComponentSources.clear();
059            _namespaceSources.clear();
060            _localizedNamespaceSources.clear();
061        }
062    
063        private synchronized IPropertySource getSourceForNamespace(INamespace namespace)
064        {
065            Resource key = namespace.getSpecificationLocation();
066    
067            IPropertySource result = (IPropertySource) _namespaceSources.get(key);
068    
069            if (result == null)
070            {
071                result = createSourceForNamespace(namespace);
072                _namespaceSources.put(key, result);
073            }
074    
075            return result;
076        }
077    
078        private synchronized IPropertySource getSourceForComponent(IComponent component)
079        {
080            Resource key = component.getSpecification().getSpecificationLocation();
081    
082            IPropertySource result = (IPropertySource) _componentSources.get(key);
083    
084            if (result == null)
085            {
086                result = createSourceForComponent(component);
087                _componentSources.put(key, result);
088            }
089    
090            return result;
091        }
092    
093        private synchronized LocalizedPropertySource getLocalizedSourceForComponent(IComponent component)
094        {
095            Resource key = component.getSpecification().getSpecificationLocation();
096    
097            LocalizedPropertySource result = (LocalizedPropertySource) _localizedComponentSources
098                    .get(key);
099    
100            if (result == null)
101            {
102                result = new LocalizedPropertySource(getSourceForComponent(component));
103    
104                _localizedComponentSources.put(key, result);
105            }
106    
107            return result;
108        }
109    
110        private synchronized LocalizedPropertySource getLocalizedSourceForNamespace(INamespace namespace)
111        {
112            Resource key = namespace.getSpecificationLocation();
113    
114            LocalizedPropertySource result = (LocalizedPropertySource) _localizedNamespaceSources
115                    .get(key);
116    
117            if (result == null)
118            {
119                result = new LocalizedPropertySource(getSourceForNamespace(namespace));
120    
121                _localizedNamespaceSources.put(key, result);
122            }
123    
124            return result;
125        }
126    
127        private IPropertySource createSourceForComponent(IComponent component)
128        {
129            IComponentSpecification specification = component.getSpecification();
130    
131            List sources = new ArrayList();
132    
133            sources.add(new PropertyHolderPropertySource(specification));
134            sources.add(getSourceForNamespace(component.getNamespace()));
135    
136            return (IPropertySource) _chainBuilder.buildImplementation(
137                    IPropertySource.class,
138                    sources,
139                    ImplMessages.componentPropertySourceDescription(specification));
140        }
141    
142        private IPropertySource createSourceForNamespace(INamespace namespace)
143        {
144            List sources = new ArrayList();
145    
146            sources.add(new PropertyHolderPropertySource(namespace.getSpecification()));
147            sources.add(_globalProperties);
148    
149            return (IPropertySource) _chainBuilder.buildImplementation(
150                    IPropertySource.class,
151                    sources,
152                    ImplMessages.namespacePropertySourceDescription(namespace));
153        }
154    
155        public String getComponentProperty(IComponent component, String propertyName)
156        {
157            return getSourceForComponent(component).getPropertyValue(propertyName);
158        }
159    
160        public String getLocalizedComponentProperty(IComponent component, Locale locale,
161                String propertyName)
162        {
163            return getLocalizedSourceForComponent(component).getPropertyValue(propertyName, locale);
164        }
165    
166        public String getNamespaceProperty(INamespace namespace, String propertyName)
167        {
168            return getSourceForNamespace(namespace).getPropertyValue(propertyName);
169        }
170    
171        public String getLocalizedNamespaceProperty(INamespace namespace, Locale locale,
172                String propertyName)
173        {
174            return getLocalizedSourceForNamespace(namespace).getPropertyValue(propertyName, locale);
175        }
176    
177        public void setChainBuilder(ChainBuilder chainBuilder)
178        {
179            _chainBuilder = chainBuilder;
180        }
181    
182        public void setGlobalProperties(IPropertySource globalProperties)
183        {
184            _globalProperties = globalProperties;
185        }
186    }