Use one action for multiple models

Question

I have about 5 models that behave very similarly. In fact, I'd like them to share an action for displaying them. For example, for models Car, Truck, Van I want to have a definition like:

[Car, Truck, Van].each do |Model|
  action_for Model do #I made this up to show what I mean
    def index
      @model = Model.all
      @model_names = @model.map(&:name).join(', ')
    end
  end
end

How would I do this so I'm not defining the same action in multiple controllers? (Which isn't very DRY) Would it be in the application_controller? And if it's not too much to ask, how could I do this so they also share the view?

UPDATE

It would be preferred if this can be outside the individual controllers. If I can get this to work right, I'd like to not even have to generate the individual controllers.

Answer 1

Would something like this work for you?

module Display
  def index
    m = self.class.to_s.chomp('Controller').classify.constantize
    @model = m.all
    @model_names = @model.map(&:name).join(', ')
  end
end

In the controllers:

class CarsController < ApplicationController
  include Display 
end

class TrucksController < ApplicationController
  include Display 
end

class VansController < ApplicationController
  include Display 
end

Edit: an attempt to do this without individual controllers

class DisplaysController < ApplicationController
  def index
    @model = params[:model].constantize.all
    @model_names = @model.map(&:name).join(', ')
  end
end

routes.rb

match "display" => "display#index", :as => :display

In a view

link_to "Display Cars", display_path(:model => "Car")
link_to "Display Trucks", display_path(:model => "Truck")
link_to "Display Vans", display_path(:model => "Van")

Note: If you've heard of extend for modules and are wondering why/when to use include vs extend, see What is the difference between include and extend in Ruby? (basically include is for instances, extend for class methods).