FunctionFactory.h

#ifndef MANTID_API_FUNCTIONFACTORY_H_
#define MANTID_API_FUNCTIONFACTORY_H_

//----------------------------------------------------------------------
// Includes
//----------------------------------------------------------------------
#include <vector>
#include "MantidAPI/DllConfig.h"
#include "MantidKernel/DynamicFactory.h"
#include "MantidKernel/SingletonHolder.h"
#include "MantidKernel/MultiThreaded.h"

#include <boost/shared_ptr.hpp>


namespace Mantid
{

namespace API
{

//----------------------------------------------------------------------
// More forward declarations
//----------------------------------------------------------------------
  class IFunction;
  class CompositeFunction;
  class Expression;

/** @class FunctionFactoryImpl

    The FunctionFactory class is in charge of the creation of concrete
    instances of fitting functions. It inherits most of its implementation from
    the Dynamic Factory base class.
    It is implemented as a singleton class.
    
    @author Roman Tolchenov, Tessella Support Services plc
    @date 27/10/2009
    
    Copyright &copy; 2007 ISIS Rutherford Appleton Laboratory & NScD Oak Ridge National Laboratory

    This file is part of Mantid.

    Mantid 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.

    Mantid 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 this program.  If not, see <http://www.gnu.org/licenses/>.

    File change history is stored at: <https://github.com/mantidproject/mantid>    
*/

  class MANTID_API_DLL FunctionFactoryImpl : public Kernel::DynamicFactory<IFunction>
  {
  public:
    /**Creates an instance of a function
     * @param type :: The function's type
     * @return A pointer to the created function
     */
    boost::shared_ptr<IFunction> createFunction(const std::string& type) const;

    ///Creates an instance of a function
    boost::shared_ptr<IFunction> createInitialized(const std::string& input) const;

    /// Query available functions based on the template type
    template<typename FunctionType>
    const std::vector<std::string>& getFunctionNames() const;

    using Kernel::DynamicFactory<IFunction>::subscribe;
    void subscribe(const std::string& className, AbstractFactory* pAbstractFactory,
                   Kernel::DynamicFactory<IFunction>::SubscribeAction replace=ErrorIfExists);

    void unsubscribe(const std::string& className);

  private:
    friend struct Mantid::Kernel::CreateUsingNew<FunctionFactoryImpl>;

    /// Private Constructor for singleton class
    FunctionFactoryImpl();
    /// Private copy constructor - NO COPY ALLOWED
    FunctionFactoryImpl(const FunctionFactoryImpl&);
    /// Private assignment operator - NO ASSIGNMENT ALLOWED
    FunctionFactoryImpl& operator = (const FunctionFactoryImpl&);
    ///Private Destructor
    virtual ~FunctionFactoryImpl();

    /// These methods shouldn't be used to create functions
    using Kernel::DynamicFactory<IFunction>::create;
    using Kernel::DynamicFactory<IFunction>::createUnwrapped;

    /// Create a simple function
    boost::shared_ptr<IFunction> createSimple(
      const Expression& expr, 
      std::map<std::string,std::string>& parentAttributes
      )const;
    /// Create a composite function
    boost::shared_ptr<CompositeFunction> createComposite(
      const Expression& expr, 
      std::map<std::string,std::string>& parentAttributes
      )const;

    /// Throw an exception
    void inputError(const std::string& str="")const;
    /// Add constraints to the created function
    void addConstraints(boost::shared_ptr<IFunction> fun,const Expression& expr)const;
    /// Add a single constraint to the created function
    void addConstraint(boost::shared_ptr<IFunction> fun,const Expression& expr)const;
    /// Add ties to the created function
    void addTies(boost::shared_ptr<IFunction> fun,const Expression& expr)const;
    /// Add a tie to the created function
    void addTie(boost::shared_ptr<IFunction> fun,const Expression& expr)const;

    mutable std::map<std::string,std::vector<std::string>> m_cachedFunctionNames;
    mutable Kernel::Mutex m_mutex;
  };

  /**
   * Query available functions based on the template type
   * @tparam FunctionType :: The type of the functions to list 
   * @returns A vector of the names of the functions matching the template type 
   */
  template<typename FunctionType>
  const std::vector<std::string>& FunctionFactoryImpl::getFunctionNames() const
  {
    Kernel::Mutex::ScopedLock _lock(m_mutex);

    const std::string soughtType(typeid(FunctionType).name());
    if ( m_cachedFunctionNames.find( soughtType ) != m_cachedFunctionNames.end() )
    {
      return m_cachedFunctionNames[soughtType];
    }

    // Create the entry in the cache and work with it directly
    std::vector<std::string>& typeNames = m_cachedFunctionNames[soughtType];
    const std::vector<std::string> names = this->getKeys();
    for( auto it = names.begin(); it != names.end(); ++it )
    {
      boost::shared_ptr<IFunction> func = this->createFunction(*it);
      if ( func && dynamic_cast<FunctionType*>(func.get()) )
      {
        typeNames.push_back(*it);
      }
    }
    return typeNames;
  }

  ///Forward declaration of a specialisation of SingletonHolder for AlgorithmFactoryImpl (needed for dllexport/dllimport) and a typedef for it.
#ifdef _WIN32
// this breaks new namespace declaraion rules; need to find a better fix
  template class MANTID_API_DLL Mantid::Kernel::SingletonHolder<FunctionFactoryImpl>;
#endif /* _WIN32 */
  typedef MANTID_API_DLL Mantid::Kernel::SingletonHolder<FunctionFactoryImpl> FunctionFactory;

  /// Convenient typedef for an UpdateNotification
  typedef FunctionFactoryImpl::UpdateNotification FunctionFactoryUpdateNotification;
  /// Convenient typedef for an UpdateNotification AutoPtr
  typedef const Poco::AutoPtr<FunctionFactoryUpdateNotification> & FunctionFactoryUpdateNotification_ptr;
} // namespace API
} // namespace Mantid

/**
 * Macro for declaring a new type of function to be used with the FunctionFactory
 */
#define DECLARE_FUNCTION(classname) \
        namespace { \
        Mantid::Kernel::RegistrationHelper register_function_##classname( \
  ((Mantid::API::FunctionFactory::Instance().subscribe<classname>(#classname)) \
        , 0)); \
        }

#endif /*MANTID_API_FUNCTIONFACTORY_H_*/