Added Quantity nesting with awesome_nested_set

Gemfile

@@ -1,3 +1,5 @@
+gem 'awesome_nested_set'
+
 group :development do
   gem "web-console"
 end

app/controllers/quantities_controller.rb

@@ -5,7 +5,6 @@ class QuantitiesController < ApplicationController
 
   def index
     @quantity = Quantity.new
-    @quantities = @project.quantities
   end
 
   def create
@@ -14,7 +13,6 @@ class QuantitiesController < ApplicationController
       flash[:notice] = 'Created new quantity'
       redirect_to project_quantities_url(@project)
     else
-      @quantities = @project.quantities
       render :index
     end
   end
@@ -32,7 +30,8 @@ class QuantitiesController < ApplicationController
     params.require(:quantity).permit(
       :name,
       :description,
-      :domain
+      :domain,
+      :parent_id
     )
   end
 

app/helpers/quantities_helper.rb

@@ -5,4 +5,11 @@ module QuantitiesHelper
       [translations[k.to_sym], k]
     end
   end
+
+  def parent_options
+    options = nested_set_options(Quantity, @quantity) do |i|
+      raw("#{' ' * i.level}#{i.name}")
+    end
+    options.unshift([t('.null_parent'), nil])
+  end
 end

app/models/quantity.rb

@@ -1,4 +1,6 @@
 class Quantity < ActiveRecord::Base
+  acts_as_nested_set dependent: :nullify, scope: :project
+
   enum domain: {
     diet: 0,
     measurement: 1,

app/views/quantities/_form.html.erb

@@ -1,13 +1,10 @@
 <%= error_messages_for @quantity %>
 
 <div class="box tabular">
-  <div class="splitcontent">
-    <div class="splitcontentleft">
-      <p><%= f.text_field :name, size: 50, required: true %></p>
-    </div>
-    <div class="splitcontentright">
-      <p><%= f.select :domain, domain_options, required: true %></p>
-    </div>
-  </div>
+  <p><%= f.select :domain, domain_options, required: true %></p>
+  <p>
+    <%= f.select :parent_id, parent_options, required: true, label: :field_parent_quantity %>
+  </p>
+  <p><%= f.text_field :name, size: 25, required: true %></p>
   <p><%= f.text_field :description, size: 200 %></p>
 </div>

app/views/quantities/index.html.erb

@@ -23,7 +23,7 @@
 </div>
 
 <h2><%= t ".heading" %></h2>
-<% if @quantities.any? %>
+<% if Quantity.roots.any? %>
   <table class="list">
     <thead>
       <tr>
@@ -34,13 +34,16 @@
       </tr>
     </thead>
     <tbody>
-      <% @quantities.each do |q| %>
-        <tr id="quantity-<%= q.id %>" class="quantity">
-          <td class="quantityname"><%= q.name %></td>
-          <td class="domain"><%= q.domain %></td>
-          <td class="description"><%= q.description %></td>
-          <td><%= delete_link quantity_path(q), data: {} %></td>
-        </tr>
+      <% Quantity.roots.each do |r| %>
+        <% Quantity.each_with_level(r.self_and_descendants) do |q, level| %>
+          <tr id="quantity-<%= q.id %>"
+              class="quantity <%= "project idnt idnt-#{level}" if level > 0 %>">
+            <td class="name"><span><%= q.name %></span></td>
+            <td class="domain"><%= q.domain %></td>
+            <td class="description"><%= q.description %></td>
+            <td><%= delete_link quantity_path(q), data: {} %></td>
+          </tr>
+        <% end %>
       <% end %>
     </tbody>
   </table>

config/locales/en.yml

@@ -4,6 +4,7 @@ en:
   field_shortname: 'Short name'
   field_action: 'Action'
   field_domain: 'Domain'
+  field_parent_quantity: 'Parent'
   body_trackers:
     index:
       heading: 'Summary'
@@ -24,6 +25,7 @@ en:
         diet: 'diet'
         measurement: 'measurement'
         exercise: 'exercise'
+      null_parent: '- none -'
   units:
     index:
       heading: 'Units'

db/migrate/001_create_units.rb

@@ -11,6 +11,10 @@ class CreateUnits < ActiveRecord::Migration
       t.string :name
       t.string :description
       t.integer :domain
+      # fields for awesome_nested_set
+      t.references :parent
+      t.integer :lft, :null => false, :index => true
+      t.integer :rgt, :null => false, :index => true
     end
 
     create_table :ingredients do |t|