Factory.hpp

/*
 * Copyright (c) 2012 David-Matthias Sichau
 * Copyright (c) 2010 Marc Kirchner
 *
 * This file is part of utillib.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef UTILIB_FACTORY_HPP__
#define UTILIB_FACTORY_HPP__


#include <exception>
#include <map>
#include <typeinfo>

namespace UtilLib {
template <typename IdentifierType, typename ProductType>
class ErrorPolicyThrowException {
 protected:
    static ProductType* onUnknownType(const IdentifierType& id) {
        throw std::bad_typeid();
    }
};

template <typename IdentifierType, typename ProductType>
class ErrorPolicyReturnNull {
 protected:
    static ProductType* onUnknownType(const IdentifierType& id) {
        return 0;
    }
};

template <
        class AbstractProduct,
        typename IdentifierType,
        template <typename,
                class> class FactoryErrorPolicy = ErrorPolicyThrowException,
        typename ProductCreatorSignature = AbstractProduct* (*)()
        >
class Factory : public FactoryErrorPolicy<
                        IdentifierType,
                        AbstractProduct
                        > {
 public:
    bool registerType(
            const IdentifierType& id,
            ProductCreatorSignature creator) {
        return productMap_.insert(typename ProductMap::value_type(id,
                        creator)).second;
    }

    bool unregisterType(const IdentifierType& id) {
        return (productMap_.erase(id) == 1);
    }

    AbstractProduct* createObject(const IdentifierType& id) const {
        typename ProductMap::const_iterator i = productMap_.find(id);
        if (i != productMap_.end()) {
            return (*i).second();
        }
        return this->onUnknownType(id);
    }

 private:
    typedef std::map<IdentifierType, ProductCreatorSignature> ProductMap;

    ProductMap productMap_;
};
}  // end namespace utillib

#endif /* UTILIB_FACTORY_HPP__ */