Middleware

Any middleware requires following 3 members:

struct context

Storing data for the middleware; can be read from another middleware or handlers

before_handle

Called before handling the request.
If res.end() is called, the operation is halted. (after_handle will still be called)
2 signatures:
void before_handle(request& req, response& res, context& ctx) if you only need to access this middleware's context.

template <typename AllContext>
void before_handle(request& req, response& res, context& ctx, AllContext& all_ctx)

You can access other middlewares' context by calling all_ctx.template get<MW>()
ctx == all_ctx.template get<CurrentMiddleware>()

after_handle

Called after handling the request.

void after_handle(request& req, response& res, context& ctx)

template <typename AllContext>
void after_handle(request& req, response& res, context& ctx, AllContext& all_ctx)

This was pulled from cookie_parser.h. Further Editing required, possibly use parts of @ipkn's wiki page.