Added Ingredient#destroy

app/controllers/ingredients_controller.rb

@@ -1,5 +1,6 @@
 class IngredientsController < ApplicationController
   before_action :find_project_by_project_id, only: [:index, :create]
+  before_action :find_ingredient, only: [:destroy]
   before_action :authorize
 
   def index
@@ -20,6 +21,11 @@ class IngredientsController < ApplicationController
   end
 
   def destroy
+    # FIXME: don't destroy if any meal depend on ingredient
+    if @ingredient.destroy
+      flash[:notice] = 'Deleted ingredient'
+    end
+    redirect_to project_ingredients_url(@project)
   end
 
   private
@@ -40,4 +46,13 @@ class IngredientsController < ApplicationController
       ]
     )
   end
+
+  # :find_* methods are called before :authorize,
+  # @project is required for :authorize to succeed
+  def find_ingredient
+    @ingredient = Ingredient.find(params[:id])
+    @project = @ingredient.project
+  rescue ActiveRecord::RecordNotFound
+    render_404
+  end
 end

app/models/ingredient.rb

@@ -6,7 +6,7 @@ class Ingredient < ActiveRecord::Base
   belongs_to :project
   belongs_to :ref_unit, class_name: 'Unit'
 
-  has_many :nutrients, inverse_of: :ingredient
+  has_many :nutrients, inverse_of: :ingredient, dependent: :destroy
   accepts_nested_attributes_for :nutrients, allow_destroy: true, reject_if: proc { |attrs|
     attrs['quantity_id'].blank? && attrs['amount'].blank?
   }