textserializer.java

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/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xerces" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.apache.org.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */


// Sep 14, 2000:
//  Fixed serializer to report IO exception directly, instead at
//  the end of document processing.
//  Reported by Patrick Higgins <[e-mail]>


package org.jasig.portal.serialize;


import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;

import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.AttributeList;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;


/**
 * Implements a text serializer supporting both DOM and SAX
 * serializing. For usage instructions see {@link Serializer}.
 * <p>
 * If an output stream is used, the encoding is taken from the
 * output format (defaults to <tt>UTF-8</tt>). If a writer is
 * used, make sure the writer uses the same encoding (if applies)
 * as specified in the output format.
 * <p>
 * The serializer supports both DOM and SAX. DOM serializing is done
 * by calling {@link #serialize(Element)} and SAX serializing is done by firing
 * SAX events and using the serializer as a document handler.
 * <p>
 * If an I/O exception occurs while serializing, the serializer
 * will not throw an exception directly, but only throw it
 * at the end of serializing (either DOM or SAX's {@link
 * org.xml.sax.ContentHandler#endDocument}.
 *
 *
 * @version $Revision: 1.3 $ $Date: 2004/09/10 17:17:27 $
 * @author <a href="mailto:[e-mail]">Assaf Arkin</a>
 * @see Serializer
 */
public class TextSerializer
    extends BaseMarkupSerializer
{


    /**
     * Constructs a new serializer. The serializer cannot be used without
     * calling {@link #setOutputCharStream(Writer)} or {@link #setOutputByteStream(OutputStream)}
     * first.
     */
    public TextSerializer()
    {
        super( new OutputFormat( Method.TEXT, null, false ) );
    }


    public void setOutputFormat( OutputFormat format )
    {
        super.setOutputFormat( format != null ? format : new OutputFormat( Method.TEXT, null, false ) );
    }


    //-----------------------------------------//
    // SAX content handler serializing methods //
    //-----------------------------------------//


    public void startElement( String namespaceURI, String localName,
                              String rawName, Attributes attrs )
        throws SAXException
    {
        startElement( rawName == null ? localName : rawName, null );
    }


    public void endElement( String namespaceURI, String localName,
                            String rawName )
        throws SAXException
    {
        endElement( rawName == null ? localName : rawName );
    }


    //------------------------------------------//
    // SAX document handler serializing methods //
    //------------------------------000---------//


    public void startElement( String tagName, AttributeList attrs )
        throws SAXException
    {
        boolean      preserveSpace;
        ElementState state;

        try {
            state = getElementState();
            if ( isDocumentState() ) {
                // If this is the root element handle it differently.
                // If the first root element in the document, serialize
                // the document's DOCTYPE. Space preserving defaults
                // to that of the output format.
                if ( ! _started )
                    startDocument( tagName );
            }
            // For any other element, if first in parent, then
            // use the parnet's space preserving.
            preserveSpace = state.preserveSpace;

            // Do not change the current element state yet.
            // This only happens in endElement().

            // Ignore all other attributes of the element, only printing
            // its contents.

            // Now it's time to enter a new element state
            // with the tag name and space preserving.
            // We still do not change the curent element state.
            state = enterElementState( null, null, tagName, preserveSpace );
        } catch ( IOException except ) {
            throw new SAXException( except );
        }
    }


    public void endElement( String tagName )
        throws SAXException
    {
        try {
            endElementIO( tagName );
        } catch ( IOException except ) {
            throw new SAXException( except );
        }
    }


    public void endElementIO( String tagName )
        throws IOException
    {
        ElementState state;

        // Works much like content() with additions for closing
        // an element. Note the different checks for the closed
        // element's state and the parent element's state.
        state = getElementState();
        // Leave the element state and update that of the parent
        // (if we're not root) to not empty and after element.
        state = leaveElementState();
        state.afterElement = true;
        state.empty = false;
        if ( isDocumentState() )
            _printer.flush();
    }


    public void processingInstructionIO( String target, String code ) throws IOException
    {
    }


    public void comment( String text )
    {
    }


    public void comment( char[] chars, int start, int length )
    {
    }


    public void characters( char[] chars, int start, int length )
        throws SAXException
    {
        ElementState state;

        try {
            state = content();
            state.doCData = state.inCData = false;
            printText( chars, start, length, true, true );
        } catch ( IOException except ) {
            throw new SAXException( except );
        }
    }


    protected void characters( String text, boolean unescaped )
        throws IOException
    {
        ElementState state;

        state = content();
        state.doCData = state.inCData = false;
        printText( text, true, true );
    }


    //------------------------------------------//
    // Generic node serializing methods methods //
    //------------------------------------------//


    /**
     * Called to serialize the document's DOCTYPE by the root element.
     * <p>
     * This method will check if it has not been called before ({@link #_started}),
     * will serialize the document type declaration, and will serialize all
     * pre-root comments and PIs that were accumulated in the document
     * (see {@link #serializePreRoot()}). Pre-root will be serialized even if
     * this is not the first root element of the document.
     */
    protected void startDocument( String rootTagName )
        throws IOException
    {
        // Required to stop processing the DTD, even though the DTD
        // is not printed.
        _printer.leaveDTD();

        _started = true;
        // Always serialize these, even if not te first root element.
        serializePreRoot();
    }


    /**
     * Called to serialize a DOM element. Equivalent to calling {@link
     * #startElement(String, String, String, Attributes)}, {@link #endElement(String, String, String)} and serializing everything
     * inbetween, but better optimized.
     */
    protected void serializeElement( Element elem )
        throws IOException
    {
        Node         child;
        ElementState state;
        boolean      preserveSpace;
        String       tagName;

        tagName = elem.getTagName();
        state = getElementState();
        if ( isDocumentState() ) {
            // If this is the root element handle it differently.
            // If the first root element in the document, serialize
            // the document's DOCTYPE. Space preserving defaults
            // to that of the output format.
            if ( ! _started )
                startDocument( tagName );
        }
        // For any other element, if first in parent, then
        // use the parnet's space preserving.
        preserveSpace = state.preserveSpace;

        // Do not change the current element state yet.
        // This only happens in endElement().

        // Ignore all other attributes of the element, only printing
        // its contents.

        // If element has children, then serialize them, otherwise
        // serialize en empty tag.
        if ( elem.hasChildNodes() ) {
            // Enter an element state, and serialize the children
            // one by one. Finally, end the element.
            state = enterElementState( null, null, tagName, preserveSpace );
            child = elem.getFirstChild();
            while ( child != null ) {
                serializeNode( child );
                child = child.getNextSibling();
            }
            endElementIO( tagName );
        } else {
            if ( ! isDocumentState() ) {
                // After element but parent element is no longer empty.
                state.afterElement = true;
                state.empty = false;
            }
        }
    }


    /**
     * Serialize the DOM node. This method is unique to the Text serializer.
     *
     * @param node The node to serialize
     */
    protected void serializeNode( Node node )
        throws IOException
    {
        // Based on the node type call the suitable SAX handler.
        // Only comments entities and documents which are not
        // handled by SAX are serialized directly.
        switch ( node.getNodeType() ) {
        case Node.TEXT_NODE : {
            String text;

            text = node.getNodeValue();
            if ( text != null )
                characters( node.getNodeValue(), true );
            break;
        }

        case Node.CDATA_SECTION_NODE : {
            String text;

            text = node.getNodeValue();
            if ( text != null )
                characters( node.getNodeValue(), true );
            break;
        }

        case Node.COMMENT_NODE :
            break;

        case Node.ENTITY_REFERENCE_NODE :
            // Ignore.
            break;

        case Node.PROCESSING_INSTRUCTION_NODE :
            break;

        case Node.ELEMENT_NODE :
            serializeElement( (Element) node );
            break;

        case Node.DOCUMENT_NODE :
            // !!! Fall through
        case Node.DOCUMENT_FRAGMENT_NODE : {
            Node         child;

            // By definition this will happen if the node is a document,
            // document fragment, etc. Just serialize its contents. It will
            // work well for other nodes that we do not know how to serialize.
            child = node.getFirstChild();
            while ( child != null ) {
                serializeNode( child );
                child = child.getNextSibling();
            }
            break;
        }

        default:
            break;
        }
    }


    protected ElementState content()
    {
        ElementState state;

        state = getElementState();
        if ( ! isDocumentState() ) {
            // If this is the first content in the element,
            // change the state to not-empty.
            if ( state.empty )
                state.empty = false;
            // Except for one content type, all of them
            // are not last element. That one content
            // type will take care of itself.
            state.afterElement = false;
        }
        return state;
    }


    protected String getEntityRef( int ch )
    {
        return null;
    }


}