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.markup;
016    
017    import java.io.CharArrayWriter;
018    import java.io.PrintWriter;
019    
020    import org.apache.tapestry.IMarkupWriter;
021    import org.apache.tapestry.NestedMarkupWriter;
022    
023    /**
024     * Nested implementation of {@link org.apache.tapestry.IMarkupWriter}. Accumulates content in a
025     * {@link java.io.CharArrayWriter}, and prints the buffered content (raw) on {@link #close()}.
026     * 
027     * @author Howard M. Lewis Ship
028     * @since 4.0
029     * @see org.apache.tapestry.IMarkupWriter#getNestedWriter()
030     */
031    public class NestedMarkupWriterImpl extends MarkupWriterImpl implements NestedMarkupWriter
032    {
033        private final IMarkupWriter _parent;
034    
035        private final CharArrayWriter _charArrayWriter;
036    
037        private boolean _closed;
038    
039        public NestedMarkupWriterImpl(IMarkupWriter parent, MarkupFilter filter)
040        {
041            // Need to do this awkward double constructor because we want
042            // to create an object and pass it to the parent constructor.
043            // Java language rules get in the way here.
044    
045            this(parent, new CharArrayWriter(), filter);
046        }
047    
048        private NestedMarkupWriterImpl(IMarkupWriter parent, CharArrayWriter writer, MarkupFilter filter)
049        {
050            super(parent.getContentType(), new PrintWriter(writer), filter);
051    
052            _parent = parent;
053            _charArrayWriter = writer;
054        }
055        
056        public String getBuffer()
057        {
058            if (_closed)
059                throw new IllegalStateException(MarkupMessages.closeOnce());
060    
061            _closed = true;
062    
063            super.close();
064    
065            return _charArrayWriter.toString();
066        }
067    
068        /**
069         * Closes the internal {@link CharArrayWriter}, then captures its content and invokes
070         * {@link org.apache.tapestry.IMarkupWriter#printRaw(String)} on the parent markup writer
071         * (the writer that created this writer).
072         */
073    
074        public void close()
075        {
076            String content = getBuffer();
077    
078            _parent.printRaw(content);
079        }
080    }