BuilderFrom.h

/***************************************************************************
 *
 * Copyright (C) 2009 Cassio Neri Moreira
 *
 * This file is part of the KeyValue library.
 *
 * The KeyValue library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 *
 * The KeyValue 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 General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with KeyValue. If not, see <http://www.gnu.org/licenses/>.
 *
 * If you modify this library, or any covered work, by linking or combining
 * it with Excel (or a modified version of that program), containing parts
 * covered by the terms of End-User License Agreement for Microsoft
 * Software, the licensors of KeyValue grant you additional permission to
 * convey the resulting work.
 *
 **************************************************************************/

#ifndef KEYVALUE_MNGT_BUILDER_BUILDERFROM_H_
#define KEYVALUE_MNGT_BUILDER_BUILDERFROM_H_

#include "keyvalue/extern/SharedPtr.h"
#include "keyvalue/frontend/LexicalToolKit.h"
#include "keyvalue/sys/exception/Exception.h"
#include "keyvalue/value/Variant.h"

namespace keyvalue {

template<typename ObjectType>
class BuilderFromVariant {

public:

  shared_ptr<ObjectType>
  getObject(const value::Variant& data) const;

private:

  virtual const char*
  getName() const = 0;

  template<typename InputType>
  shared_ptr<ObjectType>
  build(const value::Variant& data) const;

}; // class BuilderFromVariant

template<typename ObjectType, typename InputType>
class BuilderFrom {

public:

  virtual shared_ptr<ObjectType>
  getObject(const InputType& data) const = 0;

}; // class BuilderFrom

/*--------------------------------------------------------------------------
 * getObject()
 *------------------------------------------------------------------------*/

template<typename ObjectType>
shared_ptr<ObjectType> BuilderFromVariant<ObjectType>::getObject(
    const value::Variant& data) const {

  using frontend::LexicalToolKit;

  if (data.is<bool> (LexicalToolKit::input))
    return build<bool> (data);

  if (data.is<double> (LexicalToolKit::input))
    return build<double> (data);

  if (data.is<ptime> (LexicalToolKit::input))
    return build<ptime> (data);

  if (data.is<string> (LexicalToolKit::input))
    return build<string> (data);

  throw ::keyvalue::LogicError() & "Unknown keyvalue::Variant content!";
}

/*--------------------------------------------------------------------------
 * build()
 *------------------------------------------------------------------------*/

template<typename ObjectType>
template<typename InputType>
shared_ptr<ObjectType> BuilderFromVariant<ObjectType>::build(
    const value::Variant& data) const {

  const BuilderFrom<ObjectType, InputType>* ptr(
      dynamic_cast<const BuilderFrom<ObjectType, InputType>*> (this));

  using frontend::LexicalToolKit;
  if (ptr)
    return ptr->getObject(data.get<InputType> (LexicalToolKit::input));

  throw RuntimeError() & "Builder '" & getName() & "'cannot build from "
    "input " & data & "'!";
}

} // namespace keyvalue

#endif // KEYVALUE_MNGT_BUILDER_BUILDERFROM_H_