(feat) count products in categories

app/frontend/src/javascript/components/store/categories/product-categories-item.tsx

@@ -51,7 +51,7 @@ export const ProductCategoriesItem: React.FC<ProductCategoriesItemProps> = ({ pr
             </button>
           </div>}
           <p className='itemInfo-name'>{category.name}</p>
-          <span className='itemInfo-count'>[count]</span>
+          <span className='itemInfo-count'>{category.products_count}</span>
         </div>
         <div className='actions'>
           {!isDragging &&

app/frontend/src/javascript/components/store/store.tsx

@@ -255,7 +255,16 @@ const Store: React.FC<StoreProps> = ({ onError, onSuccess, currentUser, uiRouter
               {categoriesTree.map(c =>
                 <div key={c.parent.id} className={`parent ${selectedCategory?.id === c.parent.id || selectedCategory?.parent_id === c.parent.id ? 'is-active' : ''}`}>
                   <p onClick={() => filterCategory(c.parent)}>
-                    {c.parent.name}<span>(count)</span>
+                    {c.parent.name}
+                    <span>
+                      {/* here we add the parent count with the sum of all children counts */}
+                      {
+                        c.parent.products_count +
+                        c.children
+                          .map(ch => ch.products_count)
+                          .reduce((sum, val) => sum + val, 0)
+                      }
+                    </span>
                   </p>
                   {c.children.length > 0 &&
                     <div className='children'>
@@ -263,7 +272,7 @@ const Store: React.FC<StoreProps> = ({ onError, onSuccess, currentUser, uiRouter
                         <p key={ch.id}
                           className={selectedCategory?.id === ch.id ? 'is-active' : ''}
                           onClick={() => filterCategory(ch)}>
-                          {ch.name}<span>(count)</span>
+                          {ch.name}<span>{ch.products_count}</span>
                         </p>
                       )}
                     </div>

app/frontend/src/javascript/models/product-category.ts

@@ -4,4 +4,5 @@ export interface ProductCategory {
   slug: string,
   parent_id?: number,
   position: number,
+  products_count: number
 }

app/models/product_category.rb

@@ -10,9 +10,9 @@ class ProductCategory < ApplicationRecord
   validates :slug, uniqueness: true
 
   belongs_to :parent, class_name: 'ProductCategory'
-  has_many :children, class_name: 'ProductCategory', foreign_key: :parent_id
+  has_many :children, class_name: 'ProductCategory', foreign_key: :parent_id, inverse_of: :parent, dependent: :nullify
 
-  has_many :products
+  has_many :products, dependent: :nullify
 
   acts_as_list scope: :parent, top_of_list: 0
 end

app/services/product_category_service.rb

@@ -3,7 +3,9 @@
 # Provides methods for ProductCategory
 class ProductCategoryService
   def self.list
-    ProductCategory.all.order(parent_id: :asc, position: :asc)
+    ProductCategory.left_outer_joins(:products)
+                   .select('product_categories.*, count(products.*) as products_count')
+                   .group('product_categories.id')
   end
 
   def self.destroy(product_category)

app/views/api/product_categories/_product_category.json.jbuilder

@@ -1,3 +1,3 @@
 # frozen_string_literal: true
 
-json.extract! product_category, :id, :name, :slug, :parent_id, :position
+json.extract! product_category, :id, :name, :slug, :parent_id, :position, :products_count

db/migrate/20221003133019_add_index_on_product_category_slug.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+# ProductCategory's slugs should validate uniqness in database
+class AddIndexOnProductCategorySlug < ActiveRecord::Migration[5.2]
+  def change
+    add_index :product_categories, :slug, unique: true
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2022_09_20_131912) do
+ActiveRecord::Schema.define(version: 2022_10_03_133019) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "fuzzystrmatch"
@@ -642,6 +642,7 @@ ActiveRecord::Schema.define(version: 2022_09_20_131912) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["parent_id"], name: "index_product_categories_on_parent_id"
+    t.index ["slug"], name: "index_product_categories_on_slug", unique: true
   end
 
   create_table "product_stock_movements", force: :cascade do |t|