Render JSON instead of HTML as default?

Question

I try to tell rails 3.2 that it should render JSON by default, and kick HTML completely like this:

respond_to :json    

def index
  @clients = Client.all
  respond_with @clients
end

With this syntax, I have to add .json to the URL. How can I achieve it?

Solution 1

You can modify your routes.rb files to specify the default format

routes.rb

resources :clients, defaults: {format: :json}

This will modify the default response format for your entire clients_controller

Solution 2

This pattern works well if you want to use the same controller actions for both. Make a web version as usual, using :html as the default format. Then, tuck the api under a path and set :json as the default there.

Rails.application.routes.draw do

  resources :products

  scope "/api", defaults: {format: :json} do
    resources :products
  end

end

Solution 3

If you don't need RESTful responding in your index action then simply render your xml response directly:

def index
  render json: Client.all
end

Solution 4

Extending Mark Swardstrom's answer, if your rails app is an API that always returns JSON responses, you could simply do

Rails.application.routes.draw do
  scope '/', defaults: { format: :json } do
    resources :products
  end
end

View more solutions

Comments

[jdoe]

@Tronic Maybe I didn't understand you correctly. I thought your action index shouldn't respond to html at all and you want it to respond to json even w/o .json in your url.

[shredding]

Can this be added globally for all resources?

[Tony - Currentuser.io]

To add default format to all resources, declare resources in a defaults block: defaults format: 'json' {resources :clients; resources :products}.

[Don Cheadle]

this is a valuable alternative to @rogeilog 's answer for those who don't want to override the default response for ALL of their controller, but just for a certain action

[rafalefighter]

is this compatible with newer rails version ? I add the line you mentiond but it still render HTML. could you please explain me how can I do this sir ? thanks

[Ryan]

This is great, you can also apply it to namespaces (and probably scopes, etc). For example namespace :api, { defaults: { format: :json } } do. Im currently doing that on Rails 5

[sameera207]

thanks @Ryan, that is what exactly I was looking for 👍

[Bibek Shrestha]

This wouldn't work for devise. You'll have to manually set the defaults: devise_for :users, defaults: {format: :json}