Rails - Dec 2006 - Route generation and clash prevention

Let''s say you''re building a movie rental website. You have
customers,
movies, and rentals to manage. REST style urls might look like this:

/customers/4
/movies/15
/rentals

You''d probably also want administrators to be able to view all of the
rentals done by a particular customer, and other similar details:

/customers/4/rentals
/movies/15/rentals
/rentals/529/customers

Except you can''t, at least not as far as I understand route generation.
Looking at routes.rb for the example:

  map.resources :movies do |movies|
    movies.resources :rentals
  end

  map.resources :rentals do | rentals|
    rentals.resources :customers
  end

  map.resources :customers do |customers|
    customers.resources :rentals
  end

These map blocks introduce ambiguity about what rental_url(1,5) should
generate - /movies/1/rentals/5 or /customers/1/movies/5. The error
message pointing this out sucks (rentals_url failed to generate from
{:controller=>"rentals", :action=>"index"}, expected:
{:controller=>"rentals", :action=>"index"}, diff: {}),
but I digress.

Instead of throwing an error in this kind of situation (which I imagine
would be relatively common), why not take a named route like
customer_rentals_url(1,5) or new_movie_rental_url(1) when there is
ambiguity?

There may be a very good reason why not, and I''m new here, so bear with
me. :)

-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
 You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

Hi --

On Sun, 17 Dec 2006, D. Scott Brown wrote:
>
> Let''s say you''re building a movie rental website. You
have customers,
> movies, and rentals to manage. REST style urls might look like this:
>
> /customers/4
> /movies/15
> /rentals
>
> You''d probably also want administrators to be able to view all of
the
> rentals done by a particular customer, and other similar details:
>
> /customers/4/rentals
> /movies/15/rentals
> /rentals/529/customers
>
> Except you can''t, at least not as far as I understand route
generation.
> Looking at routes.rb for the example:
>
>  map.resources :movies do |movies|
>    movies.resources :rentals
>  end
>
>  map.resources :rentals do | rentals|
>    rentals.resources :customers
>  end
>
>  map.resources :customers do |customers|
>    customers.resources :rentals
>  end
Do you really want both rentals/customers and customers/rentals?
> These map blocks introduce ambiguity about what rental_url(1,5) should
> generate - /movies/1/rentals/5 or /customers/1/movies/5. The error
> message pointing this out sucks (rentals_url failed to generate from
> {:controller=>"rentals", :action=>"index"},
expected:
> {:controller=>"rentals", :action=>"index"}, diff:
{}), but I digress.
Yes, that error message is a source of much frustration as well as
amusement :-)
> Instead of throwing an error in this kind of situation (which I imagine
> would be relatively common), why not take a named route like
> customer_rentals_url(1,5) or new_movie_rental_url(1) when there is
> ambiguity?
>
> There may be a very good reason why not, and I''m new here, so bear
with
> me. :)
I''m a little uncertain what you want the end result to be (a couple of
things in the examples aren''t clear to me), but it sounds like you
could make use of name prefixes -- for example:

   map.resources :rentals do |rentals|
     rentals.resources :movies, :name_prefix => "movies_"
     rentals.resources :customers, :name_prefix => "customers_"
   end

which (if I''ve got [untested] syntax right) should give you
rentals_movies_url, rentals_customers_url, and so forth.  To do it the
other way around, you would do:

   map.resources :movies do |movies|
     movies.resources :rentals, :name_prefix => "movies_"
   end

and the same for :customers, to get movies_rentals and
customers_rentals.


David

-- 
Q. What''s a good holiday present for the serious Rails developer?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black)
    aka The Ruby book for Rails developers!
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)

--~--~---------~--~----~------------~-------~--~----~
 You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

> I''m a little uncertain what you want the end result to be (a
couple of
> things in the examples aren''t clear to me), but it sounds like you
> could make use of name prefixes -- for example:
> 
>    map.resources :rentals do |rentals|
>      rentals.resources :movies, :name_prefix => "movies_"
>      rentals.resources :customers, :name_prefix =>
"customers_"
>    end
> 
> which (if I''ve got [untested] syntax right) should give you
> rentals_movies_url, rentals_customers_url, and so forth.  To do it the
> other way around, you would do:
> 
>    map.resources :movies do |movies|
>      movies.resources :rentals, :name_prefix => "movies_"
>    end
> 
> and the same for :customers, to get movies_rentals and
> customers_rentals.
Eureka, that did the trick!

Thanks David, you rock. The only catch is that the prefix is truly a 
prefix - you must do movie_new_rental_path instead of the catchier 
new_movie_rental_path.


-- 
Posted via http://www.ruby-forum.com/.

--~--~---------~--~----~------------~-------~--~----~
 You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---