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.portlet.bindings;
016    
017    import java.util.Map;
018    
019    import javax.portlet.PortletRequest;
020    
021    import org.apache.hivemind.ApplicationRuntimeException;
022    import org.apache.hivemind.Location;
023    import org.apache.hivemind.util.Defense;
024    import org.apache.tapestry.binding.AbstractBinding;
025    import org.apache.tapestry.coerce.ValueConverter;
026    
027    /**
028     * Allows access to a Portlet user attrbute.
029     * 
030     * @author Howard M. Lewis Ship
031     * @since 4.0
032     */
033    public class UserAttributeBinding extends AbstractBinding
034    {
035        private final PortletRequest _request;
036    
037        private final String _attributeName;
038    
039        public UserAttributeBinding(String description, ValueConverter valueConverter,
040                Location location, PortletRequest request, String attributeName)
041        {
042            super(description, valueConverter, location);
043    
044            Defense.notNull(request, "request");
045            Defense.notNull(attributeName, "attributeName");
046    
047            _request = request;
048            _attributeName = attributeName;
049        }
050    
051        public boolean isInvariant()
052        {
053            // These can always be changed.
054            return false;
055        }
056    
057        private Map getUserInfo()
058        {
059            Map result = (Map) _request.getAttribute(PortletRequest.USER_INFO);
060    
061            if (result == null)
062                throw new ApplicationRuntimeException(BindingsMessages.noUserInfo(), getLocation(),
063                        null);
064    
065            return result;
066        }
067    
068        public Object getObject()
069        {
070            return getUserInfo().get(_attributeName);
071        }
072    
073        public void setObject(Object value)
074        {
075            String asString = (String) getValueConverter().coerceValue(value, String.class);
076    
077            getUserInfo().put(_attributeName, asString);
078        }
079    }