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

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;
    } // namespace details

    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
    } // namespace details

    inline details::parameter_validator FactoryParams::get_for(const char* tag) const {
        return details::parameter_validator(tag, this);
    }
} // namespace log4cpp

#endif // h_3e645482_ae6a_43e5_8f81_abbc4200212d