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