Back to Aiohttp

Abstract Base Classes

docs/abc.rst

4.0.0a16.9 KB
Original Source

.. module:: aiohttp.abc

.. _aiohttp-abc:

Abstract Base Classes

Abstract routing

aiohttp has abstract classes for managing web interfaces.

The most part of :mod:aiohttp.web is not intended to be inherited but few of them are.

aiohttp.web is built on top of few concepts: application, router, request and response.

router is a pluggable part: a library user may build a router from scratch, all other parts should work with new router seamlessly.

:class:aiohttp.abc.AbstractRouter has the only mandatory method: :meth:aiohttp.abc.AbstractRouter.resolve coroutine. It must return an :class:aiohttp.abc.AbstractMatchInfo instance.

If the requested URL handler is found :meth:aiohttp.abc.AbstractMatchInfo.handler is a :term:web-handler for requested URL and :attr:aiohttp.abc.AbstractMatchInfo.http_exception is None.

Otherwise :attr:aiohttp.abc.AbstractMatchInfo.http_exception is an instance of :exc:~aiohttp.web.HTTPException like 404: NotFound or 405: Method Not Allowed. :meth:aiohttp.abc.AbstractMatchInfo.handler raises :attr:~aiohttp.abc.AbstractMatchInfo.http_exception on call.

.. class:: AbstractRouter

Abstract router, :class:aiohttp.web.Application accepts it as router parameter and returns as :attr:aiohttp.web.Application.router.

.. method:: resolve(request) :async:

  Performs URL resolving. It's an abstract method, should be
  overridden in *router* implementation.

  :param request: :class:`aiohttp.web.Request` instance for
                  resolving, the request has
                  :attr:`aiohttp.web.Request.match_info` equals to
                  ``None`` at resolving stage.

  :return: :class:`aiohttp.abc.AbstractMatchInfo` instance.

.. class:: AbstractMatchInfo

Abstract match info, returned by :meth:aiohttp.abc.AbstractRouter.resolve call.

.. attribute:: http_exception

  :exc:`aiohttp.web.HTTPException` if no match was found, ``None``
  otherwise.

.. method:: handler(request) :async:

  Abstract method performing :term:`web-handler` processing.

  :param request: :class:`aiohttp.web.Request` instance for
                  resolving, the request has
                  :attr:`aiohttp.web.Request.match_info` equals to
                  ``None`` at resolving stage.
  :return: :class:`aiohttp.web.StreamResponse` or descendants.

  :raise: :class:`aiohttp.web.HTTPException` on error

.. method:: expect_handler(request) :async:

  Abstract method for handling *100-continue* processing.

Abstract Class Based Views

For class based view support aiohttp has abstract :class:AbstractView class which is awaitable (may be uses like await Cls() or yield from Cls() and has a request as an attribute.

.. class:: AbstractView

An abstract class, base for all class based views implementations.

Methods __iter__ and __await__ should be overridden.

.. attribute:: request

  :class:`aiohttp.web.Request` instance for performing the request.

.. class:: AbstractCookieJar

The cookie jar instance is available as :attr:aiohttp.ClientSession.cookie_jar.

The jar contains :class:~http.cookies.Morsel items for storing internal cookie data.

API provides a count of saved cookies::

   len(session.cookie_jar)

These cookies may be iterated over::

   for cookie in session.cookie_jar:
       print(cookie.key)
       print(cookie["domain"])

An abstract class for cookie storage. Implements :class:collections.abc.Iterable and :class:collections.abc.Sized.

.. method:: update_cookies(cookies, response_url=None)

  Update cookies returned by server in ``Set-Cookie`` header.

  :param cookies: a :class:`collections.abc.Mapping`
     (e.g. :class:`dict`, :class:`~http.cookies.SimpleCookie`) or
     *iterable* of *pairs* with cookies returned by server's
     response.

  :param str response_url: URL of response, ``None`` for *shared
     cookies*.  Regular cookies are coupled with server's URL and
     are sent only to this server, shared ones are sent in every
     client request.

.. method:: filter_cookies(request_url)

  Return jar's cookies acceptable for URL and available in
  ``Cookie`` header for sending client requests for given URL.

  :param str response_url: request's URL for which cookies are asked.

  :return: :class:`http.cookies.SimpleCookie` with filtered
     cookies for given URL.

.. method:: clear(predicate=None)

  Removes all cookies from the jar if the predicate is ``None``. Otherwise remove only those :class:`~http.cookies.Morsel` that ``predicate(morsel)`` returns ``True``.

  :param predicate: callable that gets :class:`~http.cookies.Morsel` as a parameter and returns ``True`` if this :class:`~http.cookies.Morsel` must be deleted from the jar.

      .. versionadded:: 3.8

.. method:: clear_domain(domain)

  Remove all cookies from the jar that belongs to the specified domain or its subdomains.

  :param str domain: domain for which cookies must be deleted from the jar.

  .. versionadded:: 3.8

Abstract Access Logger

.. class:: AbstractAccessLogger

An abstract class, base for all :class:aiohttp.web.RequestHandler access_logger implementations

Method log should be overridden.

.. method:: log(request, response, time)

  :param request: :class:`aiohttp.web.Request` object.

  :param response: :class:`aiohttp.web.Response` object.

  :param float time: Time taken to serve the request.

.. attribute:: enabled

    Return True if logger is enabled.

    Override this property if logging is disabled to avoid the
    overhead of calculating details to feed the logger.

    This property may be omitted if logging is always enabled.

Abstract Resolver

.. class:: AbstractResolver

An abstract class, base for all resolver implementations.

Method resolve should be overridden.

.. method:: resolve(host, port, family)

  Resolve host name to IP address.

  :param str host: host name to resolve.

  :param int port: port number.

  :param int family: socket family.

  :return: list of :class:`aiohttp.abc.ResolveResult` instances.

.. method:: close()

  Release resolver.

.. class:: ResolveResult

Result of host name resolution.

.. attribute:: hostname

  The host name that was provided.

.. attribute:: host

  The IP address that was resolved.

.. attribute:: port

  The port that was resolved.

.. attribute:: family

  The address family that was resolved.

.. attribute:: proto

  The protocol that was resolved.

.. attribute:: flags

  The flags that were resolved.