// @HEADER
// ***********************************************************************
// 
//                    Teuchos: Common Tools Package
//                 Copyright (2004) Sandia Corporation
// 
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
// 
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
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//  
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//  
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
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// Questions? Contact Michael A. Heroux (maherou@sandia.gov) 
// 
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// @HEADER

#ifndef Teuchos_TREEBUILDINGXMLHANDLER_H
#define Teuchos_TREEBUILDINGXMLHANDLER_H

/*! \file Teuchos_TreeBuildingXMLHandler.hpp
    \brief Defines a class for assembling an XMLObject from XML input
*/

#include "Teuchos_ConfigDefs.hpp"
#include "Teuchos_XMLObject.hpp"
#include <list>
#include <stack>


namespace Teuchos
{

  /** \ingroup XML
   * \brief TreeBuildingXMLHandler assembles a XMLObject from your XML input.
   */
  class TreeBuildingXMLHandler
    {
      typedef Teuchos::map<std::string, std::string> Map;
    public:
      /** \brief Empty constructor */
      TreeBuildingXMLHandler();

      /** \brief Retrieve the entire XML tree */
      const XMLObject& getObject() const
        {
          // valid XML requires a root object; we will allow empty XML files
          TEST_FOR_EXCEPTION(
            root_.isEmpty(), EmptyXMLError
            ,"Error, An empty XML std::string or file was specified!"
            "  The XML specification requires at minimum the presence"
            " of a root element!" );
          return root_.getChild(0);
        }

      /** \brief Process character data */
      void characters(const std::string& chars);

      /** \brief Receive notification of the end of an element */
      int endElement(const std::string& tag);

      /** \brief Receive notification of the start of an element */
      void startElement(const std::string& tag,
                        const Map& attributes);

    private:
      XMLObject root_;
      XMLObject current_;
      std::stack<XMLObject> path_;
    };
}


#endif