Question

I’ve been drying some code, one of this refactors is as following:
I have 3 controllers ( ConstructionCompanies, RealEstateCompanies, People) all of which had the following pattern:

class ConstructionCompaniesController < ApplicationController
before_filter :correct_user, :only => [:edit, :update]

private
   def correct_user
      @company = ConstructionCompany.find(params[:id]) 
      if(current_user.owner != @company.user)
        redirect_to(root_path)
      end
    end   

class RealEstateCompaniesController < ApplicationController
  before_filter :correct_user, :only => [:edit, :update]
...

private
   def correct_user
      @company = RealEstateCompany.find(params[:id]) 
      if(current_user.owner != @company.user)
        redirect_to(root_path)
      end
    end   

As you can see the correct_user is repeated in each controller.
So what I did inside I helper that is included for all of them I created a method:

def correct_user_for_seller_of_controller(controller)
    #"User".classify will return the class User etc.
    @seller = controller.controller_name.classify.constantize.find(params[:id])     
    redirect_to(root_path) unless (current_user == @seller.user)
  end                            

Know inside each controller I have:

class ConstructionCompaniesController < ApplicationController

  before_filter :only => [:edit, :update] do |controller| correct_user_for_seller_of_controller(controller) end           

class RealEstateCompaniesController < ApplicationController

 before_filter :only => [:edit, :update] do |controller| correct_user_for_seller_of_controller(controller) end           

I like the fact that is DRY now, but the problem is that it seems a little to complex for me, hard to understand. Did I went too far ?

Answer 1

Add the correct_user method to the ApplicationController class.

class ApplicationController
  def correct_user_for_seller_of_controller
    #"User".classify will return the class User etc.
    @seller = controller_name.classify.constantize.find(params[:id])     
    redirect_to(root_path) unless (current_user == @seller.user)
  end  
end

In your controllers use the new method as a filter method:

class RealEstateCompaniesController < ApplicationController

 before_filter :correct_user_for_seller_of_controller, :only => [:edit, :update]

end