Question

Rails newbie here, trying to get a new controller working.

When I try to show ann existing instance, I get an undefined method error on a helper method.
Code follows.
Any idea why getRecipes would be undefined?!

Controller:

    def show
       id = params[:id]
       recipe_ids = ConcreteMenu.getRecipes(id)

       respond_to do |format|
          format.html
       end
  end

Model

require 'json/objects'

class ConcreteMenu < ActiveRecord::Base
  has_many :menu_recipes
  has_many :recipes, :through => :menu_recipes

  belongs_to :menu

  def self.getRecipes(id)
      recipes = MenuRecipe.find(:all, :conditions => {:concrete_menu_id => id}, :select => 'id')
   end
end

Answer 1

It would help if you pasted the error text, because your explanation leaves a lot of possibilities for what could be wrong. BUT, there is an easier way to get what you want. The value of defining “has_many” relationships is that instead of calling a class method and passing the id of a concrete menu to get its associated recipes, you can just do this:

def show
  @concrete_menu = ConcreteMenu.find(params[:id], :include => :recipes)
end

Now you’ll have the menu object, and @concrete_menu.recipes returns an array of recipes you need. This feature is already built in, no need to reinvent the wheel.

Also, I noticed you were attempting to collect id’s in the controller instead of the objects themselves. This suggests that you’re going back and actually retrieving the records in the view itself. This is less efficient, and more difficult to troubleshoot when things go wrong. My example above will do what you need in a better (and more rails-accepted) way.