src/org/apache/xml/dtm/ref/IncrementalSAXSource.java

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999,2000 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
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 * 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/)."
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 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Xerces" and "Apache Software Foundation" must
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 * 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/>.
 */

package org.apache.xml.dtm.ref;

import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
import org.xml.sax.ContentHandler;
import org.xml.sax.XMLReader;

/** <p>IncrementalSAXSource is an API that delivers a small number of
 * SAX events each time a request is made from a "controller"
 * coroutine.  See IncrementalSAXFilter and IncrementalSAXFilter_Xerces
 * for examples.
 * 
 * Note that interaction is via the deliverMoreNodes
 * method, and therefore coroutine support is not exposed
 * here.</p>
 * */
public interface IncrementalSAXSource
{
  // ------------------------------------------------------------------
  // SAX Output API
  // ------------------------------------------------------------------

  /** Register a SAX-style content handler for us to output to
   */
  public void setContentHandler(ContentHandler handler);

  /**  Register a SAX-style lexical handler for us to output to
   */
  public void setLexicalHandler(org.xml.sax.ext.LexicalHandler handler);

  /**  Register a SAX-style DTD handler for us to output to
   */
  public void setDTDHandler(org.xml.sax.DTDHandler handler);

  // ------------------------------------------------------------------
  // Command Input API
  // ------------------------------------------------------------------

  /** deliverMoreNodes() is a simple API which tells the thread in which the
   * IncrementalSAXSource is running to deliver more events (true),
   * or stop delivering events and close out its input (false).
   *
   * This is intended to be called from one of our partner coroutines,
   * and serves to encapsulate the coroutine communication protocol.
   *
   * @param parsemore If true, tells the incremental SAX stream to deliver
   * another chunk of events. If false, finishes out the stream.
   *
   * @return Boolean.TRUE if the IncrementalSAXSource believes more data
   * may be available for further parsing. Boolean.FALSE if parsing
   * ran to completion, or was ended by deliverMoreNodes(false).
   * */
  public Object deliverMoreNodes (boolean parsemore);

  // ------------------------------------------------------------------
  // Parse Thread Convenience API
  // ------------------------------------------------------------------

  /** Launch an XMLReader's parsing operation, feeding events to this
   * IncrementalSAXSource. In some implementations, this may launch a
   * thread which runs the previously supplied XMLReader's parse() operation.
   * In others, it may do other forms of initialization.
   *
   * @throws SAXException is parse thread is already in progress
   * or parsing can not be started.
   * */
  public void startParse(InputSource source) throws SAXException;
    
} // class IncrementalSAXSource