Source code for molten.middleware

# This file is a part of molten.
# Copyright (C) 2018 CLEARTYPE SRL <[email protected]>
# molten is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or (at
# your option) any later version.
# molten is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# License for more details.
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <>.

from typing import Any, Callable

from .app import BaseApp
from .errors import HeaderMissing, HTTPError
from .http import HTTP_200, HTTP_406, Request, Response
from .http.headers import HeadersDict

[docs]class ResponseRendererMiddleware: """A middleware that renders responses. """ def __call__(self, handler: Callable[..., Any]) -> Callable[..., Response]: def handle(app: BaseApp, request: Request) -> Response: try: headers: HeadersDict = {} response = handler() if isinstance(response, Response): return response elif isinstance(response, tuple): if len(response) == 2: status, response = response elif len(response) == 3: status, response, headers = response else: raise RuntimeError("Response tuple must be (status, data) or (status, data, headers).") else: status, response = HTTP_200, response except HTTPError as e: status, response, headers = e.status, e.response, e.headers try: accept_header = request.headers["accept"] except HeaderMissing: accept_header = "*/*" for mime in accept_header.split(","): mime, _, _ = mime.partition(";") for renderer in app.renderers: if mime == "*/*" or renderer.can_render_response(mime): response = renderer.render(status, response) response.headers.add_all(headers) return response return Response(HTTP_406, content="Not Acceptable") return handle