FunctionEncoder.h

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/*  Copyright (C) 2008 National Institute For Space Research (INPE) - Brazil.

    This file is part of the TerraLib - a Framework for building GIS enabled applications.

    TerraLib 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 3 of the License,
    or (at your option) any later version.

    TerraLib 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 TerraLib. See COPYING. If not, write to
    TerraLib Team at <terralib-team@terralib.org>.
 */

/*!
  \file terralib/dataaccess/query/FunctionEncoder.h

  \brief A query encoder for general function expressions.
*/

#ifndef __TERRALIB_DATAACCESS_INTERNAL_FUNCTIONENCODER_H
#define __TERRALIB_DATAACCESS_INTERNAL_FUNCTIONENCODER_H

// TerraLib
#include "SQLFunctionEncoder.h"

namespace te
{
  namespace da
  {
    /*!
      \class FunctionEncoder
      
      \brief An SQL encoder for general function expressions.

      It encodes a function expression using the following convetions:
      <ul>
      <li>for functions with no arguments: function-name()</li>
      <li>for functions with 1 argument: function-name(arg)</li>
      <li>for functions with more than 1 argument: function-name(arg1, arg2, ..., argn)</li>
      </ul>

      \sa Function, TemplateEncoder, AbstractOperatorEncoder, UnaryOperatorEncoder, FunctionEncoder, FunctionNoArgsEncoder
    */
    class TEDATAACCESSEXPORT FunctionEncoder : public SQLFunctionEncoder
    {
      public:

        /*! \brief Constructor.

            \param name Function name.
        */
        FunctionEncoder(const std::string& name) : SQLFunctionEncoder(name) {}

        /*! \brief Destructor. */
        ~FunctionEncoder() {}

        /*!
          \brief It encodes the function to a SQL notation.

          \param f     The function to be translated to a SQL notation.
          \param alias The function alias in the data source query language.
          \param buff  The destination string buffer where the translation will be written.
          \param v     The SQL visitor that will be used to visit the arguments expression.
        */
        void toSQL(const Function& f,
                   std::string& buff,
                   SQLVisitor& v) const;
    };

  } // end namespace da
}   // end namespace te

#endif  // __TERRALIB_DATAACCESS_INTERNAL_FUNCTIONENCODER_H