// Created on: 1997-12-10
// Created by: Denis PASCAL
// Copyright (c) 1997-1999 Matra Datavision
// Copyright (c) 1999-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#ifndef _TDataStd_Relation_HeaderFile
#define _TDataStd_Relation_HeaderFile

#include "TDataStd_Expression.hxx"

//! Relation attribute.
//! ==================
//!
//! * Data Structure of the Expression is stored in a
//! string and references to variables used by the string
//!
//! Warning: To be consistent, each Variable referenced by the
//! relation must have its equivalent in the string
class TDataStd_Relation : public TDataStd_Expression
{

public:
  //! class methods
  //! =============
  Standard_EXPORT static const Standard_GUID& GetID();

  //! Find, or create, an Relation attribute.
  //! Real methods
  //! ============
  Standard_EXPORT static occ::handle<TDataStd_Relation> Set(const TDF_Label& label);

  Standard_EXPORT TDataStd_Relation();

  Standard_EXPORT void SetRelation(const TCollection_ExtendedString& E);

  Standard_EXPORT const TCollection_ExtendedString& GetRelation() const;

  Standard_EXPORT const Standard_GUID& ID() const override;

  Standard_EXPORT Standard_OStream& Dump(Standard_OStream& anOS) const override;

  //! Dumps the content of me into the stream
  Standard_EXPORT void DumpJson(Standard_OStream& theOStream, int theDepth = -1) const override;

  DEFINE_DERIVED_ATTRIBUTE(TDataStd_Relation, TDataStd_Expression)
};

#endif // _TDataStd_Relation_HeaderFile