feature/Create notifications and associate with follows

Author: LewisYoul

app/assets/stylesheets/_sidebar.scss

@@ -17,6 +17,7 @@
 .menu-button {
   &--wrapper {
     display: flex;
+    position: relative;
   }
 
   &--icon {
@@ -27,6 +28,18 @@
     margin-left: 14px;
   }
 
+  &--notification {
+    position: absolute;
+    top: 18px;
+    left: 55px;
+    width: 14px;
+    height: 14px;
+    background-color: $color-purple;
+    border-radius: 50%;
+    font-size: 12px;
+    color: white;
+  }
+
   &--item {
     flex: 1;
     display: flex;

app/helpers/application_helper.rb

@@ -6,4 +6,14 @@ def tabs_class_for_active_tab(tab_id, param_tab_id)
   def tabs_details_class_for_active_tab(tab_id, param_tab_id)
     "hidden" unless tab_id.to_sym == param_tab_id.to_sym
   end
+
+  def notification_counter(user)
+    count = current_user.notifications.unread.size
+
+    if count > 0
+      count_for_display = count > 9 ? 9 : count
+
+      "<span class='menu-button--notification'>#{count_for_display}</span>".html_safe
+    end
+  end
 end

app/models/follow.rb

@@ -1,4 +1,5 @@
 class Follow < ApplicationRecord
+  has_many :notifications, as: :notifiable, dependent: :destroy
   # The user being followed
   belongs_to :followed_user, foreign_key: :followed_user_id, class_name: 'User'
 

app/models/notification.rb

@@ -0,0 +1,6 @@
+class Notification < ApplicationRecord
+  belongs_to :user
+  belongs_to :notifiable, polymorphic: true
+
+  scope :unread, -> { where(read: false) }
+end

app/models/user.rb

@@ -11,6 +11,7 @@ class User < ApplicationRecord
   # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
   devise :database_authenticatable, :registerable, :recoverable, :rememberable, :confirmable, :validatable
 
+  has_many :notifications
   has_many :folders
   has_many :snippet_folders, through: :folders
 
@@ -80,7 +81,8 @@ def avatar_url
   end
 
   def follow(user)
-    Follow.create(followed_user_id: user.id, follower_id: id)
+    follow = Follow.create(followed_user_id: user.id, follower_id: id)
+    follow.notifications.create(user: user)
   end
 
   def unfollow(user)

app/views/shared/_sidebar.html.erb

@@ -12,6 +12,13 @@
           <span class="menu-button--name">Home</span>
         <% end %>
       </div>
+      <div class="menu-button--wrapper">
+        <%= link_to folders_path, class: request.fullpath == folders_path ? 'menu-button--item-active' : 'menu-button--item' do %>
+          <%= notification_counter(current_user) %>
+          <img src="/icons/icons8-notification-24.png" width="22">
+          <span class="menu-button--name">Notifications</span>
+        <% end %>
+      </div>
       <div class="menu-button--wrapper">
         <%= link_to folders_path, class: request.fullpath == folders_path ? 'menu-button--item-active' : 'menu-button--item' do %>
           <img src="/icons/icons8-folder.svg" width="22">

db/migrate/20201231171047_create_notifications.rb

@@ -0,0 +1,11 @@
+class CreateNotifications < ActiveRecord::Migration[6.0]
+  def change
+    create_table :notifications do |t|
+      t.references :user, null: false, foreign_key: true
+      t.references :notifiable, polymorphic: true, null: false
+      t.boolean :read, null: false, default: false
+
+      t.timestamps
+    end
+  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: 2020_12_30_115654) do
+ActiveRecord::Schema.define(version: 2020_12_31_171047) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -71,6 +71,17 @@
     t.index ["user_id"], name: "index_likes_on_user_id"
   end
 
+  create_table "notifications", force: :cascade do |t|
+    t.bigint "user_id", null: false
+    t.string "notifiable_type", null: false
+    t.bigint "notifiable_id", null: false
+    t.boolean "read", default: false, null: false
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["notifiable_type", "notifiable_id"], name: "index_notifications_on_notifiable_type_and_notifiable_id"
+    t.index ["user_id"], name: "index_notifications_on_user_id"
+  end
+
   create_table "snippet_folders", force: :cascade do |t|
     t.bigint "snippet_id", null: false
     t.bigint "folder_id", null: false
@@ -118,6 +129,7 @@
   add_foreign_key "comments", "users"
   add_foreign_key "likes", "snippets"
   add_foreign_key "likes", "users"
+  add_foreign_key "notifications", "users"
   add_foreign_key "snippet_folders", "folders"
   add_foreign_key "snippet_folders", "snippets"
 end