src/org/apache/xalan/xsltc/trax/TransformerHandlerImpl.java

/*
 * @(#)$Id$
 *
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 2001-2003 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 "Xalan" 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 apache@apache.org.
 *
 * 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
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * 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) 2001, Sun
 * Microsystems., http://www.sun.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * @author Morten Jorgensen
 *
 */

package org.apache.xalan.xsltc.trax;

import org.xml.sax.*;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.ext.DeclHandler;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.transform.*;
import javax.xml.transform.sax.*;

import org.apache.xalan.xsltc.Translet;
import org.apache.xalan.xsltc.TransletOutputHandler;
import org.apache.xalan.xsltc.dom.DOMImpl;
import org.apache.xalan.xsltc.dom.DOMBuilder;
import org.apache.xalan.xsltc.dom.DTDMonitor;
import org.apache.xalan.xsltc.runtime.AbstractTranslet;
import org.apache.xalan.xsltc.compiler.util.ErrorMsg;

/**
 * Implementation of a JAXP1.1 TransformerHandler
 */
public class TransformerHandlerImpl implements TransformerHandler, DeclHandler {

    private TransformerImpl  _transformer;
    private AbstractTranslet _translet = null;
    private String           _systemId;
    private DOMImpl          _dom = null;
    private ContentHandler   _handler = null;
    private LexicalHandler   _lexHandler = null;
    private DTDMonitor       _dtd = null;
    private Result           _result = null;

    private boolean          _done = false; // Set in endDocument()

    /**
     * A flag indicating whether this transformer handler implements the 
     * identity transform.
     */
    private boolean _isIdentity = false;

    /**
     * Cosntructor - pass in reference to a TransformerImpl object
     */
    public TransformerHandlerImpl(TransformerImpl transformer) {
	// Save the reference to the transformer
	_transformer = transformer;

	if (transformer.isIdentity()) {
	    // Set initial handler to the empty handler
	    _handler = new DefaultHandler();
	    _isIdentity = true;
	}
	else {
	    // Get a reference to the translet wrapped inside the transformer
	    _translet = _transformer.getTranslet();

	    // Create a DOMBuilder object and get the handler
	    _dom = new DOMImpl();
	    _handler = _dom.getBuilder();
	    _lexHandler = (LexicalHandler) _handler;

	    // Create a new DTD monitor
	    _dtd = new DTDMonitor();
	}
    }

    /**
     * Implements javax.xml.transform.sax.TransformerHandler.getSystemId()
     * Get the base ID (URI or system ID) from where relative URLs will be
     * resolved.
     * @return The systemID that was set with setSystemId(String id)
     */
    public String getSystemId() {
	return _systemId;
    }

    /**
     * Implements javax.xml.transform.sax.TransformerHandler.setSystemId()
     * Get the base ID (URI or system ID) from where relative URLs will be
     * resolved.
     * @param id Base URI for this stylesheet
     */
    public void setSystemId(String id) {
	_systemId = id;
    }

    /**
     * Implements javax.xml.transform.sax.TransformerHandler.getTransformer()
     * Get the Transformer associated with this handler, which is needed in
     * order to set parameters and output properties.
     * @return The Transformer object
     */
    public Transformer getTransformer() {
	return _transformer;
    }

    /**
     * Implements javax.xml.transform.sax.TransformerHandler.setResult()
     * Enables the user of the TransformerHandler to set the to set the Result
     * for the transformation.
     * @param result A Result instance, should not be null
     * @throws IllegalArgumentException if result is invalid for some reason
     */
    public void setResult(Result result) throws IllegalArgumentException {
	_result = result;

	if (_isIdentity) {
	    try {
		// Connect this object with output system directly
		TransletOutputHandler outputHandler =
		    _transformer.getOutputHandler(result);
		_transformer.transferOutputProperties(outputHandler);

		_handler = new SAX2TO(outputHandler);
		_lexHandler = (LexicalHandler) _handler;
	    }
	    catch (TransformerException e) {
		_result = null;
	    }
	}
	else if (_done) {
	    // Run the transformation now, if not already done
	    try {
		_transformer.setDOM(_dom);
		_transformer.transform(null, _result);
	    }
	    catch (TransformerException e) {
		// What the hell are we supposed to do with this???
		throw new IllegalArgumentException(e.getMessage());
	    }
	}
    }

    /**
     * Implements org.xml.sax.ContentHandler.characters()
     * Receive notification of character data.
     */
    public void characters(char[] ch, int start, int length) 
	throws SAXException 
    {
	_handler.characters(ch, start, length);
    }

    /**
     * Implements org.xml.sax.ContentHandler.startDocument()
     * Receive notification of the beginning of a document.
     */
    public void startDocument() throws SAXException {
	// Make sure setResult() was called before the first SAX event
	if (_result == null) {
	    ErrorMsg err = new ErrorMsg(ErrorMsg.JAXP_SET_RESULT_ERR);
	    throw new SAXException(err.toString());
	}

	if (!_isIdentity) {
	    // Set document URI
	    _dom.setDocumentURI(_systemId);
	}

	// Proxy call
	_handler.startDocument();
    }

    /**
     * Implements org.xml.sax.ContentHandler.endDocument()
     * Receive notification of the end of a document.
     */
    public void endDocument() throws SAXException {
	// Signal to the DOMBuilder that the document is complete
	_handler.endDocument();

	if (!_isIdentity) {
	    // Run the transformation now if we have a reference to a Result object
	    if (_result != null) {
		try {
		    _transformer.setDOM(_dom);
		    _transformer.setDTDMonitor(_dtd);	// for id/key
		    _transformer.transform(null, _result);
		}
		catch (TransformerException e) {
		    throw new SAXException(e);
		}
	    }
	    // Signal that the internal DOM is build (see 'setResult()').
	    _done = true;

	    // Set this DOM as the transformer's DOM
	    _transformer.setDOM(_dom);
	}
    }
	
    /**
     * Implements org.xml.sax.ContentHandler.startElement()
     * Receive notification of the beginning of an element.
     */
    public void startElement(String uri, String localName,
			     String qname, Attributes attributes)
	throws SAXException 
    {
	_handler.startElement(uri, localName, qname, attributes);
    }
	
    /**
     * Implements org.xml.sax.ContentHandler.endElement()
     * Receive notification of the end of an element.
     */
    public void endElement(String namespaceURI, String localName, String qname)
	throws SAXException 
    {
	_handler.endElement(namespaceURI, localName, qname);
    }

    /**
     * Implements org.xml.sax.ContentHandler.processingInstruction()
     * Receive notification of a processing instruction.
     */
    public void processingInstruction(String target, String data)
	throws SAXException 
    {
	_handler.processingInstruction(target, data);
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.startCDATA()
     */
    public void startCDATA() throws SAXException { 
	if (_lexHandler != null) {
	    _lexHandler.startCDATA();
	}
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.endCDATA()
     */
    public void endCDATA() throws SAXException { 
	if (_lexHandler != null) {
	    _lexHandler.endCDATA();
	}
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.comment()
     * Receieve notification of a comment
     */
    public void comment(char[] ch, int start, int length) 
	throws SAXException 
    { 
	if (_lexHandler != null) {
	    _lexHandler.comment(ch, start, length);
	}
    }

    /**
     * Implements org.xml.sax.ContentHandler.ignorableWhitespace()
     * Receive notification of ignorable whitespace in element
     * content. Similar to characters(char[], int, int).
     */
    public void ignorableWhitespace(char[] ch, int start, int length)
	throws SAXException 
    {
	_handler.ignorableWhitespace(ch, start, length);
    }

    /**
     * Implements org.xml.sax.ContentHandler.setDocumentLocator()
     * Receive an object for locating the origin of SAX document events. 
     */
    public void setDocumentLocator(Locator locator) {
	_handler.setDocumentLocator(locator);
    }

    /**
     * Implements org.xml.sax.ContentHandler.skippedEntity()
     * Receive notification of a skipped entity.
     */
    public void skippedEntity(String name) throws SAXException {
	_handler.skippedEntity(name);
    }

    /**
     * Implements org.xml.sax.ContentHandler.startPrefixMapping()
     * Begin the scope of a prefix-URI Namespace mapping.
     */
    public void startPrefixMapping(String prefix, String uri) 
	throws SAXException {
	_handler.startPrefixMapping(prefix, uri);
    }

    /**
     * Implements org.xml.sax.ContentHandler.endPrefixMapping()
     * End the scope of a prefix-URI Namespace mapping.
     */
    public void endPrefixMapping(String prefix) throws SAXException {
	_handler.endPrefixMapping(prefix);
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.startDTD()
     */
    public void startDTD(String name, String publicId, String systemId) 
	throws SAXException
    { 
	if (_lexHandler != null) {
	    _lexHandler.startDTD(name, publicId, systemId);
	}
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.endDTD()
     */
    public void endDTD() throws SAXException {
	if (_lexHandler != null) {
	    _lexHandler.endDTD();
	}
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.startEntity()
     */
    public void startEntity(String name) throws SAXException { 
	if (_lexHandler != null) {
	    _lexHandler.startEntity(name);
	}
    }

    /**
     * Implements org.xml.sax.ext.LexicalHandler.endEntity()
     */
    public void endEntity(String name) throws SAXException { 
	if (_lexHandler != null) {
	    _lexHandler.endEntity(name);
	}
    }

    /**
     * Implements org.xml.sax.DTDHandler.unparsedEntityDecl()
     */
    public void unparsedEntityDecl(String name, String publicId, 
	String systemId, String notationName) throws SAXException 
    {
	_dtd.unparsedEntityDecl(name, publicId, systemId, notationName);
    }

    /**
     * Implements org.xml.sax.DTDHandler.notationDecl()
     */
    public void notationDecl(String name, String publicId, String systemId) 
	throws SAXException
    {
	_dtd.notationDecl(name, publicId, systemId);
    }

    /**
     * Implements org.xml.sax.ext.DeclHandler.attributeDecl()
     */
    public void attributeDecl(String eName, String aName, String type, 
	String valueDefault, String value) throws SAXException 
    {
	_dtd.attributeDecl(eName, aName, type, valueDefault, value);
    }

    /**
     * Implements org.xml.sax.ext.DeclHandler.elementDecl()
     */
    public void elementDecl(String name, String model) 
	throws SAXException
    {
	_dtd.elementDecl(name, model);
    }

    /**
     * Implements org.xml.sax.ext.DeclHandler.externalEntityDecl()
     */
    public void externalEntityDecl(String name, String publicId, String systemId) 
	throws SAXException
    {
	_dtd.externalEntityDecl(name, publicId, systemId);
    }

    /**
     * Implements org.xml.sax.ext.DeclHandler.externalEntityDecl()
     */
    public void internalEntityDecl(String name, String value) 
	throws SAXException
    {
	_dtd.internalEntityDecl(name, value);
    }
}