Set a before action to all member routes?

Question

Playing around with Rails 4, I noticed that it defines a before_action filter set_[model], that is called for the actions show, edit, update and destroy.

It is in fact very useful, but I don't see much sense in not having it to all member actions. After all, if you are using a member action, you want to act on that member, thus you need to recover it from database at some point.

Note that by member actions, I also means the ones configured on routes.rb in the members block.

Is there a straight-forward way to do this, without list all member actions on the before_action filter?

Edit: To clarify, the whole point is use some rails magic to get all member routes and generate the array that would be pass in the :only. So I can do something like

before_action set_model only: all_member_routes

where all_member_routes is a piece of code that returns all member routes for my model.

Or even better,

before_action set_model, only_member_actions: true

Answer 1

The show, edit, update, destroy actions are precisely all member actions. They are the only ones that require to find the model.

If you have your own member action, then you'll have to add it to the list yourself.

before_action :set_item, only: [:edit, ..., :my_member_action]

Or, you can use the :except option to exclude all the collection actions that do not need it:

before_action :set_item, except: [:index, :create]

This way, if you add other member actions, you wont have to change anything. Personally, I prefer to be explicit and use :only.

I'm pretty sure there is no easier way to do it, you can't detect all member actions automatically.

---

edit:

I really don't think you should do that but...

You can access the name of your controller with the controller_name method.

Getting the routes related to the controller:

routes = Rails.application.routes.routes.select { |r| r.defaults[:controller] == controller_name }

Then, I think the best way to see if a route is a member route is that the @parts array includes :id. Maybe you can find a more robust way.

So I would do:

routes.select { |r| r.parts.include?(:id) }.map { |r| r.defaults[:action] }.map &:to_sym

That would give you: [:show, :preview, :my_challenges] for

 resources :users, only: [:index, :show], controller: 'accounts/users' do
   member do
     get :preview
     get :my_challenges
   end
 end

---

class ApplicationController < ActionController::Base 

    def member_routes
        Rails.application.routes.routes
            .select { |r| r.defaults[:controller] == controller_name && r.parts.include?(:id) }
            .map { |r| r.defaults[:action] }
            .map(&:to_sym)
    end

end

class UsersController < ApplicationController
    before_action set_model, only: member_routes
end

Answer 2

If you ask for a before_action without :only or :except options, it will apply to all member actions:

class ApplicationController < ActionController::Base
  before_action :require_login

  private

  def require_login
    unless logged_in?
      flash[:error] = "You must be logged in to access this section"
      redirect_to new_login_url # halts request cycle
    end
  end
end

In this particular case, it will require login from all actions on all controllers, since controllers will inherit from ApplicationController.

You can skip a before_action if you need it (for example, you need to skip require_login if you want to login into the system or sign up) like this:

class LoginsController < ApplicationController
  skip_before_action :require_login, only: [:new, :create]
end

Source: Rails Guides

---

So, in your particular case:

You could have one usual UserController:

class UserController < ApplicationController
  def index
  end


  ...
  /* you define here `index`, `create`, `update`, ... */
  def destroy
    ...
  end
end

And you could have a separate controller with all your member actions:

class UserCustomController < ApplicationController
  before_action :set_model

  def profile
    ...
  end

  def preview
  end   

  def custom_member_action
  end

  ...
  /* all your member actions */
end

This would be actually better than having a single controller with lots of methods.