src/ScopedHandler.hh

/*
 * This file is part of peekabot.
 *
 * peekabot 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.
 *
 * peekabot 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/>.
 */

#ifndef __PEEKABOT_SCOPED_HANDLER_HH
#define __PEEKABOT_SCOPED_HANDLER_HH

#include <map>
#include <vector>
#include <string>
#include <stdexcept>
#include <boost/function.hpp>

#include "XMLHandler.hh"
#include "ScopedMap.hh"

namespace peekabot
{
    class ScopedHandler : public XMLHandler
    {
    public:
        typedef boost::function<
            void (const std::string&, AttributeMap&,
                  ScopedHandler* handler)> ElementStartFunctor;
        typedef boost::function<
            void (const std::string&, ScopedHandler* handler)> CharacterFunctor;
        
        typedef boost::function<
            void (const std::string&, ScopedHandler* handler)> ElementEndFunctor;

        typedef boost::function<void (ScopedHandler* handler)> HandlerFunctor;

        typedef ElementStartFunctor UnhandledElementFunctor;
        
        typedef std::pair<ElementStartFunctor, ElementEndFunctor> StartEndPair;

        typedef std::map<std::string, ElementStartFunctor> StartFunctorMap;
    
        struct TagScope
        {
            TagScope()
                : unhandled_functor(&default_unhandled) {}

            CharacterFunctor cdata_functor;

            StartFunctorMap start_functors;

            std::vector<ElementEndFunctor> end_functors;

            UnhandledElementFunctor unhandled_functor;

        private:
            static void default_unhandled(
                const std::string &tag_name,
                AttributeMap &,
                ScopedHandler *handler) throw(std::runtime_error)
            {
                throw std::runtime_error(
                    "Unhandled start tag encountered: " + tag_name);
            }
        };

        ScopedHandler(HandlerFunctor start_handler = do_nothing,
                      HandlerFunctor end_handler = do_nothing,
                      HandlerFunctor failure_handler = do_nothing);

        virtual void on_start_element(const std::string & tag_name,
                                      AttributeMap & attributes)
            throw(std::exception);

        virtual void on_end_element(const std::string & tag_name)
            throw(std::exception);
        
        virtual void on_cdata(const std::string & cdata)
            throw(std::exception);
        
        virtual void on_start_document() throw(std::exception);


        virtual void on_end_document() throw(std::exception);

        virtual void on_failure() throw(std::exception);

        ScopedMap & get_variables();

        void enter_scope(const TagScope & tag_handlers);

        void enter_scope();

        void duplicate_scope();

        bool add_start_handler(const std::string &name,
                               ElementStartFunctor start_handler);

        void set_start_document_handler(HandlerFunctor start_handler);

        void set_end_document_handler(HandlerFunctor end_handler);

        void set_failure_handler(HandlerFunctor failure_handler);

        TagScope &get_current_scope() throw(std::runtime_error);


    private:
        static void do_nothing(ScopedHandler* handler) {}

        std::stack<TagScope> m_scoped_tag_handlers;
        ScopedMap m_scoped_variables;

        HandlerFunctor m_start_handler;
        HandlerFunctor m_end_handler;
        HandlerFunctor m_failure_handler;

        bool m_new_scope;
    };
    
}
#endif //__PEEKABOT_SCOPED_HANDLER_HH