// -*- mode:C++; tab-width:2; c-basic-offset:2; indent-tabs-mode:nil -*- 
// Copyright (C) 2000-2005 by Roger Rene Kommer / artefaktur, Kassel, Germany.
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public License (LGPL).
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// License ACDK-FreeLicense document enclosed in the distribution
// for more for more details.
// This file is part of the Artefaktur Component Development Kit:
//                         ACDK
// Please refer to
// - http://www.acdk.de
// - http://www.artefaktur.com
// - http://acdk.sourceforge.net
// for more information.
// $Header: /cvsroot/acdk/acdk/acdk_xml/src/org/xml/sax/EntityResolver.h,v 1.13 2005/02/05 10:45:38 kommer Exp $
// Documentation written by David Megginson
// NO WARRANTY!  This class documentation is in the Public Domain.
#ifndef org_xml_sax_EntityResolver_h
#define org_xml_sax_EntityResolver_h

#include <acdk.h>
#include <acdk/lang/String.h>
#include <acdk/io/IOException.h>

#include "SAXException.h"
#include "InputSource.h"

namespace org {
namespace xml {
namespace sax {


 * Basic interface for resolving entities.
 * <blockquote>
 * <em>This module, both source code and documentation, is in the
 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
 * for further information.
 * </blockquote>
 * <p>If a SAX application needs to implement customized handling
 * for external entities, it must implement this interface and
 * register an instance with the SAX driver using the
 * {@link org.xml.sax.XMLReader#setEntityResolver setEntityResolver}
 * method.</p>
 * <p>The XML reader will then allow the application to intercept any
 * external entities (including the external DTD subset and external
 * parameter entities, if any) before including them.</p>
 * <p>Many SAX applications will not need to implement this interface,
 * but it will be especially useful for applications that build
 * XML documents from databases or other specialised input sources,
 * or for applications that use URI types other than URLs.</p>
 * <p>The following resolver would provide the application
 * with a special character stream for the entity with the system
 * identifier "http://www.myhost.com/today":</p>
 * <pre>
 * import org.xml.sax.EntityResolver;
 * import org.xml.sax.InputSource;
 * public class MyResolver implements EntityResolver {
 *   public InputSource resolveEntity (String publicId, String systemId)
 *   {
 *     if (systemId.equals("http://www.myhost.com/today")) {
 *              // return a special input source
 *       MyReader reader = new MyReader();
 *       return new InputSource(reader);
 *     } else {
 *              // use the default behaviour
 *       return null;
 *     }
 *   }
 * }
 * </pre>
 * <p>The application can also use this interface to redirect system
 * identifiers to local URIs or to look up replacements in a catalog
 * (possibly by using the public identifier).</p>
 * @since SAX 1.0
   @author Roger Rene Kommer (acdk mapping)
 * @see org.xml.sax.XMLReader#setEntityResolver
 * @see org.xml.sax.InputSource
class ACDK_ORG_XML_PUBLIC EntityResolver
     * Allow the application to resolve external entities.
     * <p>The parser will call this method before opening any external
     * entity except the top-level document entity.  Such entities include
     * the external DTD subset and external parameter entities referenced
     * within the DTD (in either case, only if the parser reads external
     * parameter entities), and external general entities referenced
     * within the document element (if the parser reads external general
     * entities).  The application may request that the parser locate
     * the entity itself, that it use an alternative URI, or that it
     * use data provided by the application (as a character or byte
     * input stream).</p>
     * <p>Application writers can use this method to redirect external
     * system identifiers to secure and/or local URIs, to look up
     * public identifiers in a catalogue, or to read an entity from a
     * database or other input source (including, for example, a dialog
     * box).  Neither XML nor SAX specifies a preferred policy for using
     * public or system IDs to resolve resources.  However, SAX specifies
     * how to interpret any InputSource returned by this method, and that
     * if none is returned, then the system ID will be dereferenced as
     * a URL.  </p>
     * <p>If the system identifier is a URL, the SAX parser must
     * resolve it fully before reporting it to the application.</p>
     * @param publicId The public identifier of the external entity
     *        being referenced, or null if none was supplied.
     * @param systemId The system identifier of the external entity
     *        being referenced.
     * @return An InputSource object describing the new input source,
     *         or null to request that the parser open a regular
     *         URI connection to the system identifier.
     * @exception org.xml.sax.SAXException Any SAX exception, possibly
     *            wrapping another exception.
     * @exception java.io.IOException A Java-specific IO exception,
     *            possibly the result of creating a new InputStream
     *            or Reader for the InputSource.
     * @see org.xml.sax.InputSource
  virtual RInputSource resolveEntity(IN(::acdk::lang::RString) s, IN(::acdk::lang::RString) s1) 
      THROWS2(RSAXException, acdk::io::RIOException) = 0;

} // namespace sax
} // namespace xml
} // namespace org
#endif //org_xml_sax_EntityResolver_h