Update CHANGES, CONTRIBUTORS and docs

CHANGES.rst

@@ -88,6 +88,7 @@ CHANGES
 
 - Implement proxy support for ClientSession.ws_connect #1025
 
+- Return named tuple from WebSocketResponse.can_prepare #1016
 
 
 0.22.5 (08-02-2016)

CONTRIBUTORS.txt

@@ -42,6 +42,7 @@ Dmitry Trofimov
 Dmytro Kuznetsov
 Dustin J. Mitchell
 Elizabeth Leddy
+Enrique Saez
 Erich Healy
 Eugene Chernyshov
 Eugene Naydenov

docs/web_reference.rst

@@ -755,12 +755,15 @@ WebSocketResponse
       :param aiohttp.web.Request request: HTTP request object, that the
                                           response answers.
 
-      :return: ``namedtuple(ok, protocol)``, *namedtuple.ok* is ``True`` on
-               success, *namedtuple.protocol* is websocket subprotocol which
-               is passed by client and accepted by server (one of *protocols*
-               sequence from :class:`WebSocketResponse` ctor).
-               *namedtuple.protocol* may be ``None`` if client and server
-               subprotocols are not overlapping.
+      :return: :class:`WebSocketReady` instance.
+
+               :attr:`WebSocketReady.ok` is
+               ``True`` on success, :attr:`WebSocketReady.protocol` is
+               websocket subprotocol which is passed by client and
+               accepted by server (one of *protocols* sequence from
+               :class:`WebSocketResponse` ctor).
+               :attr:`WebSocketReady.protocol` may be ``None`` if
+               client and server subprotocols are not overlapping.
 
       .. note:: The method never raises exception.
 
@@ -948,6 +951,32 @@ WebSocketResponse
 .. seealso:: :ref:`WebSockets handling<aiohttp-web-websockets>`
 
 
+WebSocketReady
+^^^^^^^^^^^^^^
+
+.. class:: WebSocketReady
+
+   A named tuple for returning result from
+   :meth:`WebSocketResponse.can_prepare`.
+
+   Has :class:`bool` check implemented, e.g.::
+
+       if not await ws.can_prepare(...):
+           cannot_start_websocket()
+
+   .. attribute:: ok
+
+      ``True`` if websocket connection can be established, ``False``
+      otherwise.
+
+
+   .. attribute:: protocol
+
+      :class:`str` represented selected websocket sub-protocol.
+
+   .. seealso:: :meth:`WebSocketResponse.can_prepare`
+
+
 json_response
 -------------