Crow/include/crow/middleware_context.h

66 lines
2.4 KiB
C++

#pragma once
#include "crow/utility.h"
#include "crow/http_request.h"
#include "crow/http_response.h"
namespace crow
{
namespace detail
{
template<typename... Middlewares>
struct partial_context : public black_magic::pop_back<Middlewares...>::template rebind<partial_context>, public black_magic::last_element_type<Middlewares...>::type::context
{
using parent_context = typename black_magic::pop_back<Middlewares...>::template rebind<::crow::detail::partial_context>;
template<int N>
using partial = typename std::conditional<N == sizeof...(Middlewares) - 1, partial_context, typename parent_context::template partial<N>>::type;
template<typename T>
typename T::context& get()
{
return static_cast<typename T::context&>(*this);
}
};
template<>
struct partial_context<>
{
template<int>
using partial = partial_context;
};
template<int N, typename Context, typename Container, typename CurrentMW, typename... Middlewares>
bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
template<typename... Middlewares>
struct context : private partial_context<Middlewares...>
//struct context : private Middlewares::context... // simple but less type-safe
{
template<int N, typename Context, typename Container>
friend typename std::enable_if<(N == 0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
template<int N, typename Context, typename Container>
friend typename std::enable_if<(N > 0)>::type after_handlers_call_helper(Container& middlewares, Context& ctx, request& req, response& res);
template<int N, typename Context, typename Container, typename CurrentMW, typename... Middlewares2>
friend bool middleware_call_helper(Container& middlewares, request& req, response& res, Context& ctx);
template<typename T>
typename T::context& get()
{
return static_cast<typename T::context&>(*this);
}
template<int N>
using partial = typename partial_context<Middlewares...>::template partial<N>;
};
} // namespace detail
} // namespace crow