/*
 * 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
 *    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 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) 1999, International
 * Business Machines, Inc., http://www.ibm.com .  For more information
 * on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/*
 * $Log: ErrorHandler.hpp,v $
 * Revision 1.6  2000/04/27 19:33:15  rahulj
 * Included <util/XercesDefs.hpp> as suggested by David N Bertoni.
 *
 * Revision 1.5  2000/02/24 20:12:55  abagchi
 * Swat for removing Log from API docs
 *
 * Revision 1.4  2000/02/12 03:31:55  rahulj
 * Removed duplicate CVS Log entries.
 *
 * Revision 1.3  2000/02/12 01:27:19  aruna1
 * Documentation updated
 *
 * Revision 1.2  2000/02/06 07:47:57  rahulj
 * Year 2K copyright swat.
 *
 * Revision 1.1.1.1  1999/11/09 01:07:45  twl
 * Initial checkin
 *
 * Revision 1.2  1999/11/08 20:45:00  rahul
 * Swat for adding in Product name and CVS comment log variable.
 *
 */


#ifndef ERRORHANDLER_HPP
#define ERRORHANDLER_HPP

#include <util/XercesDefs.hpp>

class SAXParseException;


/**
  * Basic interface for SAX error handlers.
  *
  * <p>If a SAX application needs to implement customized error
  * handling, it must implement this interface and then register an
  * instance with the SAX parser using the parser's setErrorHandler
  * method.  The parser will then report all errors and warnings
  * through this interface.</p>
  *
  * <p> The parser shall use this interface instead of throwing an
  * exception: it is up to the application whether to throw an
  * exception for different types of errors and warnings.  Note,
  * however, that there is no requirement that the parser continue to
  * provide useful information after a call to fatalError (in other
  * words, a SAX driver class could catch an exception and report a
  * fatalError).</p>
  *
  * <p>The HandlerBase class provides a default implementation of this
  * interface, ignoring warnings and recoverable errors and throwing a
  * SAXParseException for fatal errors.  An application may extend
  * that class rather than implementing the complete interface
  * itself.</p>
  *
  * @see Parser#setErrorHandler
  * @see SAXParseException#SAXParseException 
  * @see HandlerBase#HandlerBase
  */

class SAX_EXPORT ErrorHandler
{
public:
    /** @name Constructors and Destructor */
    //@{
    /** Default constructor */
    ErrorHandler()
    {
    }

    /** Desctructor */
    virtual ~ErrorHandler()
    {
    }
    //@}

    /** @name The error handler interface */
    //@{
   /**
    * Receive notification of a warning.
    *
    * <p>SAX parsers will use this method to report conditions that
    * are not errors or fatal errors as defined by the XML 1.0
    * recommendation.  The default behaviour is to take no action.</p>
    *
    * <p>The SAX parser must continue to provide normal parsing events
    * after invoking this method: it should still be possible for the
    * application to process the document through to the end.</p>
    *
    * @param exception The warning information encapsulated in a
    *                  SAX parse exception.
    * @exception SAXException Any SAX exception, possibly
    *            wrapping another exception.
    * @see SAXParseException#SAXParseException 
    */
    virtual void warning(const SAXParseException& exception) = 0;

  /**
    * Receive notification of a recoverable error.
    *
    * <p>This corresponds to the definition of "error" in section 1.2
    * of the W3C XML 1.0 Recommendation.  For example, a validating
    * parser would use this callback to report the violation of a
    * validity constraint.  The default behaviour is to take no
    * action.</p>
    *
    * <p>The SAX parser must continue to provide normal parsing events
    * after invoking this method: it should still be possible for the
    * application to process the document through to the end.  If the
    * application cannot do so, then the parser should report a fatal
    * error even if the XML 1.0 recommendation does not require it to
    * do so.</p>
    *
    * @param exception The error information encapsulated in a
    *                  SAX parse exception.
    * @exception SAXException Any SAX exception, possibly
    *            wrapping another exception.
    * @see SAXParseException#SAXParseException 
    */
    virtual void error(const SAXParseException& exception) = 0;

  /**
    * Receive notification of a non-recoverable error.
    *
    * <p>This corresponds to the definition of "fatal error" in
    * section 1.2 of the W3C XML 1.0 Recommendation.  For example, a
    * parser would use this callback to report the violation of a
    * well-formedness constraint.</p>
    *
    * <p>The application must assume that the document is unusable
    * after the parser has invoked this method, and should continue
    * (if at all) only for the sake of collecting addition error
    * messages: in fact, SAX parsers are free to stop reporting any
    * other events once this method has been invoked.</p>
    *
    * @param exception The error information encapsulated in a
    *                  SAX parse exception.  
    * @exception SAXException Any SAX exception, possibly
    *            wrapping another exception.
    * @see SAXParseException#SAXParseException
    */
    virtual void fatalError(const SAXParseException& exception) = 0;
    
    /**
    * Reset the Error handler object on its reuse
    *
    * <p>This method helps in reseting the Error handler object
    * implementational defaults each time the Error handler is begun.</p>
    *
    */
    virtual void resetErrors() = 0;


    //@}

private :
    /* Unimplemented constructors and operators */
    
    /* Copy constructor */
    ErrorHandler(const ErrorHandler&);

    /* Assignment operator */
    void operator=(const ErrorHandler&);
    
};

#endif
