Improve documentation for CBV

Author: asvetlov

docs/web.rst

@@ -188,6 +188,8 @@ application developers can organize handlers in classes if they so wish::
    app.router.add_route('GET', '/greet/{name}', handler.handle_greeting)
 
 
+.. _aiohttp-web-class-based-views:
+
 Class Based Views
 ^^^^^^^^^^^^^^^^^
 

docs/web_reference.rst

@@ -1411,29 +1411,29 @@ In general the result may be any object derived from
 View
 ^^^^
 
-Base class for class based views. Implementations should derive from
-:class:`View` and override methods for handling HTTP verbs like
-``get()`` or ``post()``::
+.. class:: View(request)
 
-    class MyView(View):
+   Inherited from :class:`AbstractView`.
 
-        async def get(self):
-            resp = await get_response(self.request)
-            return resp
+   Base class for class based views. Implementations should derive from
+   :class:`View` and override methods for handling HTTP verbs like
+   ``get()`` or ``post()``::
 
-        async def post(self):
-            resp = await post_response(self.request)
-            return resp
+       class MyView(View):
 
-    app.router.add_route('*', '/view', MyView)
+           async def get(self):
+               resp = await get_response(self.request)
+               return resp
 
-The view raises *405 Method Not allowed*
-(:class:`HTTPMEthodNowAllowed`) if requested web verb is not
-supported.
+           async def post(self):
+               resp = await post_response(self.request)
+               return resp
 
-.. class:: View(request)
+       app.router.add_route('*', '/view', MyView)
 
-   Inherited from :class:`AbstractView`.
+   The view raises *405 Method Not allowed*
+   (:class:`HTTPMEthodNowAllowed`) if requested web verb is not
+   supported.
 
    :param request: instance of :class:`Request` that has initiated a view
                    processing.
@@ -1448,6 +1448,8 @@ supported.
    ``get()``, ``head()``, ``options()``, ``patch()``, ``post()``,
    ``put()``, ``trace()``.
 
+.. seealso:: :ref:`aiohttp-web-class-based-views`
+
 
 Utilities
 ---------