FactoryParams.hh

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/*
 * Copyright 2002, LifeLine Networks BV (www.lifeline.nl). All rights reserved.
 * Copyright 2002, Bastiaan Bakker. All rights reserved.
 *
 * See the COPYING file for the terms of usage and distribution.
 */

#if !defined(h_3e645482_ae6a_43e5_8f81_abbc4200212d)
#define h_3e645482_ae6a_43e5_8f81_abbc4200212d

#include <map>
#include <string>
#include <sstream>
#include <stdexcept>
#include "Portability.hh"

namespace log4cpp
{
   class FactoryParams;
   namespace details
   {
      class base_validator_data
      {
         public:
            base_validator_data(const char* tag, const FactoryParams* params) : tag_(tag), params_(params){}

         protected:
            const char* tag_;
            const FactoryParams* params_;

            template<typename T>
            void assign(const std::string& param_value, T& value) const
            {
               assign_impl(param_value, value);
            }

            template<typename T>
            void assign_impl(const std::string& param_value, T& value) const
            {
               std::stringstream s;
               s << param_value;
               s >> value;
            }

            void assign_impl(const std::string& param_value, std::string& value) const
            {
               value = param_value;
            }

            void throw_error(const char* param_name) const
            {
               std::stringstream s;
               s << "Property '" << param_name << "' required to configure " << tag_;
               throw std::runtime_error(s.str());
            }
      };

      class parameter_validator;
   }

   class LOG4CPP_EXPORT FactoryParams
   {
         typedef std::map<std::string, std::string> storage_t;
                 
                            storage_t storage_;
      
      public:
         typedef storage_t::const_iterator const_iterator;

         const std::string& operator[](const std::string& v) const;
         std::string& operator[](const std::string& v) { return storage_[v]; }
         details::parameter_validator get_for(const char* tag) const;
         const_iterator find(const std::string& t) const;
         const_iterator begin() const { return storage_.begin(); }
         const_iterator end() const { return storage_.end(); }
   };

   namespace details
   {
      class optional_params_validator;
      class required_params_validator : public base_validator_data
      {
         public:
            required_params_validator(const char* tag, const FactoryParams* params) : base_validator_data(tag, params) {}

#if defined(_MSC_VER) && _MSC_VER < 1300
            template<typename T>
            optional_params_validator optional(const char* param, T& value) const { optional_params_validator v(tag_, params_); v(param, value); return v; }
#else
            template<typename T>
            optional_params_validator optional(const char* param, T& value) const;
#endif
            
            template<typename T>
            const required_params_validator& operator()(const char* param, T& value) const
            {
               FactoryParams::const_iterator i = params_->find(param);
               if (i != params_->end())
                  assign(i->second, value);
               else
                  throw_error(param);

               return *this;
            }

      };
      
      class optional_params_validator : public base_validator_data
      {
         public:
            optional_params_validator(const char* tag, const FactoryParams* params) : base_validator_data(tag, params) {}

            template<typename T>
            required_params_validator required(const char* param, T& value) const { required_params_validator v(tag_, params_); v(param, value); return v; }

            template<typename T>
            const optional_params_validator& operator()(const char* param, T& value) const
            {
               FactoryParams::const_iterator i = params_->find(param);
               if (i != params_->end())
                  assign(i->second, value);

               return *this;

            }
      };

      class parameter_validator : public base_validator_data
      {
         public:
            parameter_validator(const char* tag, const FactoryParams* params) : base_validator_data(tag, params) {}

            template<typename T>
            required_params_validator required(const char* param, T& value) const { required_params_validator v(tag_, params_); v(param, value); return v; }

            template<typename T>
            optional_params_validator optional(const char* param, T& value) const { optional_params_validator v(tag_, params_); v(param, value); return v; }
      };

#if !(defined(_MSC_VER) && _MSC_VER < 1300)
      template<typename T>
      optional_params_validator 
      required_params_validator::optional(const char* param, T& value) const 
      { 
         optional_params_validator v(tag_, params_); 
         v(param, value); 
         return v; 
      }
#endif
   }

   inline details::parameter_validator FactoryParams::get_for(const char* tag) const 
   {
      return details::parameter_validator(tag, this); 
   }
}

#endif // h_3e645482_ae6a_43e5_8f81_abbc4200212d