Restricting Ruby on Rails Routes with :only and :except
Generating All Routes for a Model
Lets say we have an item model in a Ruby on Rails application. To create standard routes for this model, we write the following in config.rb:
Rails.application.routes.draw do
resources :items
end
We can run rails routes to see the routes created by the code above:
$ rails routes -c items
Prefix Verb URI Pattern Controller#Action
items GET /items(.:format) items#index
POST /items(.:format) items#create
new_item GET /items/new(.:format) items#new
edit_item GET /items/:id/edit(.:format) items#edit
item GET /items/:id(.:format) items#show
PATCH /items/:id(.:format) items#update
PUT /items/:id(.:format) items#update
DELETE /items/:id(.:format) items#destroy
What if we don’t need all of these routes though? We can use :only and :except to restrict the routes that are created for a model.
Restricting Routes with :only
If we only need a few routes, it makes sense to use :only to create only the routes we need. For example, if we only want the index and show routes, we can specify them inside an array after only::
Rails.application.routes.draw do
resources :items, only: [:index, :show]
end
This results in only 2 routes being created and we can verify with rails routes:
$ rails routes -c items
Prefix Verb URI Pattern Controller#Action
items GET /items(.:format) items#index
item GET /items/:id(.:format) items#show
Restricting Routes with :except
:except works in the opposite way. Instead of specifying the routes we want to create, we specify the ones we don’t want to create.
If we take the example from above and replace only: with :except, we can see what happens:
Rails.application.routes.draw do
resources :items, except: [:index, :show]
end
This time we can see that all routes except for index and show were created:
$ rails routes -c items
Prefix Verb URI Pattern Controller#Action
items POST /items(.:format) items#create
new_item GET /items/new(.:format) items#new
edit_item GET /items/:id/edit(.:format) items#edit
item PATCH /items/:id(.:format) items#update
PUT /items/:id(.:format) items#update
DELETE /items/:id(.:format) items#destroy
Restricting a Single Route
Note that if you need to restrict a single route with either :only or :except, there is no need to place the route in an array. Write it as a symbol after :only or :except like so:
Using except::
Rails.application.routes.draw do
resources :items, except: :index
end
Using only::
Rails.application.routes.draw do
resources :items, only: :index
end
References: