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