Undefined instance method “respond_to” in Rails 5 API Controller

Question

In rails 5 created with --api I have an error

NoMethodError (undefined method `respond_to\' for #
Did         


        

Answer 1

ActionController::API does not include the ActionController::MimeResponds module. If you want to use respond_to you need to include MimeResponds.

class ApplicationController < ActionController::API
  include ActionController::MimeResponds
end


class Api::MyController < ApplicationController
  def method1
    # ...
    respond_to do |format|
      format.xml { render(xml: "fdsfds") }
      format.json { render(json: "fdsfdsfd" ) }
    end
  end
end

Source: ActionController::API docs

Answer 2

As of Rails 4.2, this functionality no longer ships with Rails, but can easily be included with the responders gem (like Max noted in comments above).

Add gem 'responders' to your Gemfile, then

$ bundle install
$ rails g responders:install

Sources:
http://edgeguides.rubyonrails.org/4_2_release_notes.html#respond-with-class-level-respond-to https://github.com/plataformatec/responders