[LRUG] REST and Associations

[Jonathan Leighton]

Thanks for your reply. I'm glad you agree with my way of thinking on
number 1.

For number 2, you raise a fair question. Truth be told I hadn't got to
validation yet. I am completely re-implementing this controller and
decided to use it as an opportunity to use REST. Thinking about it like
that though, it seems reasonable to render "new" from #create - I've
gone with that.

Cheers!

Jon

On Wed, 2007-02-21 at 23:42 +0000, Jonas Bengtsson wrote:
> Hi,
> 
> I'm no RESTful in Rails expert by any means, but I'll give it a go.
> 
> 1) I don't see any need for there to be a one-to-one mapping of models 
> and RESTful controllers. The controllers are the way the app exposes 
> itself to the web. The models are an implementation detail. For some 
> models there's a natural one-to-one mapping to a controller, which means 
> less work. When there isn't a one-to-one mapping you need to do a little 
> more work in the controller, but that doesn't seem like a reason to 
> compromise in the way your app works.
> 
> Having said that, the resource generator creates a model as well, I'm 
> not entirely sure why that is.
> 
> 2) How do you handle validation errors in your "create" action? Don't 
> you render the "new" action? If so, I don't see that much of a 
> difference, doing the same thing but for your select boxes.
> 
> Cheers,
>   Jonas
> 
> Jonathan Leighton wrote:
> > So I've been playing with REST lately and it all seems pretty spiffy but
> > I am a little confused on the issue of associations.
> > 
> > Issue #1
> > --------
> > 
> > We have a large database with a lot of tables and a lot of
> > relationships. The client wants to be able to create a new resource, and
> > said resource has lots of required associations. It would not make sense
> > to create these associations separately to the original resource so that
> > is happening all in one form on one page. Is this okay? That doesn't
> > make me a bad person in DHH's eyes does it?
> > 
> > Issue #2
> > --------
> > 
> > Similar to #1. Said resource has a has_and_belongs_to_many association.
> > In the non-RESTful version, these were selected from select boxes. When
> > creating a new resource, you'd be presented with one select box. If you
> > wanted another you could click "add another". This would post the page
> > back to the "new" action, which would recognise which submit button had
> > been pressed and redraw the form with one more select box (and therefore
> > association).
> > 
> > This is all fine and dandy but in the happy land of REST the form gets
> > posted to the "create" action. I guess the fundamental problem is
> > actually that in order to do the same thing I'd have to allow the create
> > action to re-show the form with the additional select box(es). That
> > would surely be evil and if DHH didn't think I'm a bad person for #1 he
> > surely would now.
> > 
> > At the moment I am handling it by having an #add_foo action and calling
> > that via ajax, which inserts the new select box. This is blatently evil
> > in a progressive enhancement sorta way but seems less evil in a RESTful
> > way.
> > 
> > Either way I am evil though. Help!
> > 
> > Thanks :)
> > 
> 
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