# Nested routes don't work for me? **URL:** \ **Category:** Rails\ **Created:** [August 15, 2008, 4:07pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964 "2008-08-15T16:07:39Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 4:07pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/1 "2008-08-15T16:07:39Z")
Hi all I’m quite new to RESTful Rails and tried a bit with a new app, but it seems I don’t comprehend something yet. I have the following two models: class CompactDisc \< ActiveRecord::Base belongs\_to :genre validates\_presence\_of :genre end class Genre \< ActiveRecord::Base has\_many :compact\_discs end In routes.rb I have the following route: ActionController::Routing::Routes.draw do |map| map.resources :compact\_discs map.resources :genres do |genre| genre.resources :compact\_discs, :name\_prefix =\> ‘genre\_’ end … end When opening localhost:3000/compact\_discs it shows me all CD’s. When opening localhost:3000/genres/1/compact\_discs it still shows me all CD’s! Shouldn’t it only display the ones that are associated to genre 1 now? Or did I miss something? I also played with map.resources :genres, :has\_many =\> :compact\_discs but this didn’t help me neither… Thanks for help 🙂 Josh ---
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 6:02pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/2 "2008-08-15T18:02:59Z")
On Aug 15, 9:07 am, Joshua M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > end > map.resources :genres do |genre| > genre.resources :compact\_discs, :name\_prefix =\> ‘genre\_’ > end > > … > end Those routes look good… > ## Thanks for help 🙂 Josh > > Posted viahttp://www.ruby-forum.com/. When you have nested routes, Rails handles _almost_ everything for you, but you need to adjust your index action to be aware of the “parent” resource: def index if params[:genre] @genre = Genre.find(params[:genre]) @compact\_discs = @genre.compact\_discs else @compact\_discs = CompactDisc.find(:all) end # continue code here end In other words, you want to detect if you’re nested inside a genre, and in that case, only show the discs for that genre. There are more elegant ways to do this, too (many people use a before\_filter, etc.) Does this help at all? Jeff REST with Rails: Oct 4, 2008, Austin, TX [http://www.purpleworkshops.com/workshops/rest-and-web-services](http://www.purpleworkshops.com/workshops/rest-and-web-services) ---
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 7:34pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/3 "2008-08-15T19:34:46Z")
> Does this help at all? > > Jeff Thanks a lot, Jeff. Can you point me into some “best practices” on how to make this work? before\_filter etc…? ---
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 7:43pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/4 "2008-08-15T19:43:58Z")
Joshua M. wrote: > > Does this help at all? > > > > Jeff > > Thanks a lot, Jeff. Can you point me into some “best practices” on how > to make this work? before\_filter etc…? Well, created one myself. You think this is safe and clean/DRY? 🙂 private def prepare\_compact\_discs genre = (params[:genre\_id] ? Genre.find(params[:genre\_id]) : nil) @compact\_discs = (genre ? genre.compact\_discs : CompactDisc.find(:all)) end Btw, in your example before you should have used params[:genre\_id], not only params[:genre]. Thanks anyway. ---
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 11:56pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/5 "2008-08-15T23:56:15Z")
> Again, I don’t think there’s a right or wrong necessarily - whatever > you think keeps the code the clearest. Thanks, interesting ways! 🙂 Let’s me feel like a complete newbie again and again 😉 ---
**Author:** ![josh](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/45deac/32.png) [@josh](https://www.ruby-forum.com/u/josh)\ **Post date:** [August 15, 2008, 8:45pm UTC](https://www.ruby-forum.com/t/nested-routes-dont-work-for-me/145964/6 "2008-08-15T20:45:20Z")
On Aug 15, 12:43 pm, Joshua M. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > private > def prepare\_compact\_discs > genre = (params[:genre\_id] ? Genre.find(params[:genre\_id]) : nil) > @compact\_discs = (genre ? genre.compact\_discs : > CompactDisc.find(:all)) > end It’s probably a matter of taste, but I tend to recommend something like this: before\_filter :find\_genre def index @compact\_discs = @genre ? @genre.compact\_discs || CompactDisc.find(:all) # … end def find\_genre @genre = Genre.find\_by\_id(params[:genre\_id]) # returns nil if not foun end Some people prefer this: before\_filter :load\_for\_genre def index # Find all discs only if we don’t have any yet @compact\_discs ||= CompactDisc.find(:all) end def load\_for\_genre @compact\_discs = Genre.find(params[:genre\_id]).compact\_discs if params[:genre\_id] end Again, I don’t think there’s a right or wrong necessarily - whatever you think keeps the code the clearest. > Btw, in your example before you should have used params[:genre\_id], not > only params[:genre]. Thanks anyway. Good catch. Jeff REST with Rails: Oct 4, 2008, Austin, TX [http://www.purpleworkshops.com/workshops/rest-and-web-services](http://www.purpleworkshops.com/workshops/rest-and-web-services)