Ruby class accessing application controller method

Question

I have a rails app acting as an API client.

Once a user signs in, a token is saved to be sent with every following request to the API.

Here is my code (really simplified):

# /lib/api_client.rb
class ApiClient
  def get(path, options = {})
    # options.merge! headers: {'Authorization' => 'Token mytoken'}
    HTTParty.get("http://api.myapp.com/#{path}", options)
  end
end

# /app/models/user.rb
class User
  def self.exists?(id)
    api.get("users/#{id}").success?
  end

  def self.api
    @api ||= ApiClient.new
  end
end

# /app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
  def signed_in?
    current_auth_token.present?
  end

  def current_auth_token
    cookies.signed[:user_token]
  end
end

My problem is that ApiClient can t access the ApplicationController so it has no way to know if there is an auth_token` or not.

Now, what would be the best way to automatically add an Authorization header containing current_auth_token to every following call to ApiClient#get ?

Another solution I though of is to initialize the ApiClient in the controller, then I could just do something like api_client.auth_token = 'mytoken' . But then, is there a proper way to access it from a model?

Answer 1

You'd have to also set a current_api_client , so that each request gets its own instance of an api_client with the correct current_auth_token . Set the api_client in your application controller but assign it to a class variable so you can easily access it from the model:

class ApplicationController < ActionController::Base
  cattr_accessor :current_api_client
  # this will reset the api_client on every request using the current_auth_token
  before_filter do |c|
    ApplicationController.current_api_client = ApiClient.new token: current_auth_token # or however you set this in the client
  end

  #...
end

Now in your model you can access ApplicationController.current_api_client .

This is one of many ways to do it. It's quick and easy and fits your posted code without too many changes.