Question

I’m looking for the best practice to solve the following situation:

I’ve got an “Additive” Model which should be many-to-many-associated with some other models.

Examples:

# Meal-Model
has_and_belongs_to_many :additives

# Offer-Model
has_and_belongs_to_many :additives

# Additive-Model
has_and_belongs_to_many :meals
has_and_belongs_to_many :meals

The routes are nested in the following way:

resources :offers do
  resources :additives
end
resources :meals do
  resources :additives
end

So I get URLs like this:

/offers/123/additives
/meals/567/additives

Both routes lead to the same controller action, which is additives#index. In the AdditivesController I check if params are available to choose which data to fetch:

class AdditivesController < ApplicationController

before_filter :offermealswitch

# GET /restaurants/1/meals/123/additives
# GET /restaurants/1/offers/123/additives
def index   
  @additives = @additivemeal.additives    
end

def offermealswitch
  if params.has_key?(:meal_id)
    @additivemeal = Meal.find(params[:meal_id])
    @type = "Meal"
  elsif params.has_key?(:offer_id)
    @additivemeal = Offer.find(params[:offer_id])
    @type = "Offer"
  end
end

end

Is this the right way to handle that problem? It works very well, but I’m not shure this is the rails way…
Thanks for your answers!

Answer 1

sigh switching to answer-space so I can at least add carriage returns and make the code not dumb.

I agree with fl00r’s answer, but would add that you’d need to instantiate the object thus:

@type = params[:type] 
@obj = @type.constantize.find(params["#{type}_id"])
@additives = @obj.additives