001    // Copyright 2007, 2008, 2010 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.tapestry5.internal.services;
016    
017    import org.apache.tapestry5.ComponentResources;
018    import org.apache.tapestry5.ContentType;
019    import org.apache.tapestry5.MetaDataConstants;
020    import org.apache.tapestry5.SymbolConstants;
021    import org.apache.tapestry5.internal.structure.Page;
022    import org.apache.tapestry5.ioc.annotations.Symbol;
023    import org.apache.tapestry5.services.MetaDataLocator;
024    
025    public class PageContentTypeAnalyzerImpl implements PageContentTypeAnalyzer
026    {
027        private final MetaDataLocator metaDataLocator;
028    
029        private final String outputCharset;
030    
031        public PageContentTypeAnalyzerImpl(MetaDataLocator metaDataLocator,
032    
033        @Symbol(SymbolConstants.CHARSET)
034        String outputCharset)
035        {
036            this.metaDataLocator = metaDataLocator;
037            this.outputCharset = outputCharset;
038        }
039    
040        public ContentType findContentType(Page page)
041        {
042            ComponentResources pageResources = page.getRootComponent().getComponentResources();
043    
044            String contentTypeString = metaDataLocator.findMeta(MetaDataConstants.RESPONSE_CONTENT_TYPE, pageResources,
045                    String.class);
046    
047            // Draconian but necessary: overwrite the content type they selected with the application-wide output charset.
048    
049            return new ContentType(contentTypeString, outputCharset);
050        }
051    }