On 30/03/12 10:25 -0400, Scott Seago wrote:
On 03/29/2012 04:34 PM, Mo Morsi wrote:
>
>I'm intrigued by this idea and don't think its a bad idea to explore
>this further.
>
>I think alot of the question comes down to at what level is the API
>satisfied. Currently it's being done at the controller layer in an 'api'
>namespace, but going along w/ your example I think its best the push
>this and as much else down to the service layer.
>
>This way the service layer can be used outside the scope of the web
>interface in a locally consumable manner. Perhaps this layer can also be
>moved into its own gem so that the end user doesn't need to pull in
>rails to use Conductor.
>
>Makes sense? Would this approach work?
>
> -Mo
I think we're getting a bit far from the original proposal here. I
think there are two different issues here that we're combining --
which makes deciding how to proceed more difficult:
1) Lets re-join the controllers that currently separate UI and API (in
some cases they're combined in the same controllers/actions with
different response types, in some cases (notably for image-related
stuff) where the controllers are completely separate
2) additional discussion about whether API and UI are served by the
same controller actions or if we separate the layers where the API is
at a lower level and the UI controllers actually make API calls rather
than the current "in the same actions" approach
So for 1) I think we've all agreed on the fundamental point -- dump
the separate api controllers. Since we've pulled out 2) as a separate
question, I think this means also keeping the same controller actions,
using separate return types to distinguish API from UI actions. This
essentially boils down to making Image controllers consistent with
other controllers that don't have the separate API versions. Since
we're trying as much as is reasonable to use RESTful routes for UI as
well as API, making separate actions for the API (in the same
controller) would prevent us from using standard action methods for
either the API or the UI
+1
on 2), I would propose that we do _not_ want the separation as you
were discussing above. For one thing there's a lot of stuff you get in
Rails for free to manage coordination between managing activerecord
objects in controllers and views. If we have a UI that only talks to
the API rather than manipulating models directly in the UI
controllers, we'll have to do more work there. In addition, for ajax
methods from the UI, we often want to get json back (rather than
javascript or HTML chunks), which means that even in the UI we'll want
direct json (i.e. API) responses. To ensure consistency in the UI
between ajax calls and HTML calls (for non-javascript, etc.) we really
want those going throuh the same controller actions.
However, even with the above point, I _do_ agree with making the
controllers as thin as possible. There's definitely stuff in our
controllers that belongs in the models, and there's probably UI-only
stuff in our controllers that belongs in the views. Before talking
about taking big chunks of the infrastructure and pulling them into
separate gems -- we have to ask what the use case is. There's no point
in doing a lot of work to pull something out unless you have a need to
pull it out there. Lots of our code needs access to the ActiveRecord
models, so even pulling things out won't remove all rails
dependencies.
I agree that we should hold off on 2, taking the steps mentioned to
remove as much logic form the controllers as possible, but I don't
think Martyn was suggesting a separate gem here, or even ripping out
the api methods into another class or controller. Rather, I read it as
'lets make the api actions on the existing controllers be more pure
rest, and any non-rest stuff goes into separate actions, calling the
rest ones inline as simple methods'. While I can see, and to some
extent, agree with this line of thinking, I do not like where it takes
us, namely divorcing the ui from being at all restful, and instead
having all custom methods. I think this is in contradiction to the
general flow of a rails app. If you have (smallish) extra things that
need doing for a UI, those can be done in the block of the response
that returns html. If there is anything complex, that should be
extracted, and in the (I would think very rare) cases where that is
not possible for some reason (say something needed only for an
ajax call) the developer could consider either a custom action, or a
metal controller (or whatever the equiv is now called in rails 3.x).
One other point -- regarding the issue around UI needing a lot of
session info that the API does not (one of the justifications for
pulling stuff out into separate layers), I'm not sure there's really a
ton that we care about in the session other than login (and that's
handled with HTTP auth in the API anyway, except for ajax-UI actions,
in which case the session is available anyway). For the most part we
shouldn't be relying on a bunch of stuff in the session between clicks
in the UI if we can avoid it.
Yes, if the UI is doing too much with the session, that is a bug, not
a reason to separate out the actions. I do not think it is currently
doing all that much though.
-j