Add user following

app/assets/stylesheets/custom.scss

@@ -153,6 +153,44 @@ aside {
   margin-top: 15px;
 }
 
+.stats {
+  overflow: auto;
+  margin-top: 0;
+  padding: 0;
+  a {
+    float: left;
+    padding: 0 10px;
+    border-left: 1px solid $gray-medium-light;
+    color: gray;
+    &:first-child {
+      padding-left: 0;
+      border: 0;
+    }
+    &:hover {
+      text-decoration: none;
+      color: black;
+    }
+  }
+  strong {
+    display: block;
+  }
+}
+
+.user_avatars {
+  overflow: auto;
+  margin-top: 10px;
+  .gravatar {
+    margin: 1px 1px;
+  }
+  a {
+    padding: 0;
+  }
+}
+
+.user.follow {
+  padding: 0;
+}
+
 // form 
 input, textarea, select, .uneditable_iput {
   border:  1px solid #bbb;

app/assets/stylesheets/relationships.scss

+// Place all the styles related to the Relationships controller here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: https://sass-lang.com/

app/controllers/relationships_controller.rb

+class RelationshipsController < ApplicationController
+  before_action :logged_in_user
+
+  def create
+    @user = User.find(params[:followed_id])
+    current_user.follow(@user)
+    respond_to do |format|
+      format.html { redirect_to @user }
+      format.js
+    end
+  end
+  
+  def destroy
+    @user = Relationship.find(params[:id]).followed
+    current_user.unfollow(@user)
+    respond_to do |format|
+      format.html { redirect_to @user }
+      format.js
+    end
+  end
+end

app/controllers/users_controller.rb

 class UsersController < ApplicationController
-  before_action :logged_in_user, only: [:index, :edit, :update, :destroy]
+  before_action :logged_in_user, only: [:index, :edit, :update, :destroy,
+                                        :following, :followers]
   before_action :correct_user, only: [:edit, :update]
   before_action :admin_user, only: :destroy
 
@@ -47,6 +48,20 @@ class UsersController < ApplicationController
     redirect_to users_url
   end
 
+  def following
+    @title = "Following"
+    @user = User.find(params[:id])
+    @users = @user.following.paginate(page: params[:page])
+    render 'show_follow'
+  end
+
+  def followers
+    @title = "Followers"
+    @user = User.find(params[:id])
+    @users = @user.followers.paginate(page: params[:page])
+    render 'show_follow'
+  end
+
   private 
 
     def user_params

app/helpers/relationships_helper.rb

+module RelationshipsHelper
+end

app/models/relationship.rb

+class Relationship < ApplicationRecord
+  belongs_to :follower, class_name: "User"
+  belongs_to :followed, class_name: "User"
+  validates :follower_id, presence: true
+  validates :followed_id, presence: true
+end

app/models/user.rb

 class User < ApplicationRecord
   has_many :microposts, dependent: :destroy
+  has_many :active_relationships,   class_name: "Relationship",
+                                    foreign_key: "follower_id",
+                                    dependent: :destroy
+  has_many :passive_relationships,  class_name: "Relationship",
+                                    foreign_key: "followed_id",
+                                    dependent: :destroy
+  has_many :following, through: :active_relationships, source: :followed
+  has_many :followers, through: :passive_relationships, source: :follower
   attr_accessor :remember_token, :activation_token, :reset_token
   before_save :downcase_email
   before_create :create_activation_digest
@@ -72,7 +80,22 @@ class User < ApplicationRecord
   # Defines a proto-feed
   # See "Following users" for the full implementtation
   def feed
-    Micropost.where("user_id = ?", id)
+    following_ids = "SELECT followed_id FROM relationships
+                      WHERE follower_id = :user_id"
+    Micropost.where("user_id IN (#{following_ids})
+                    OR user_id = :user_id", user_id: id)
+  end
+
+  def follow(other_user)
+    following << other_user
+  end
+
+  def unfollow(other_user)
+    following.delete(other_user)
+  end
+
+  def following?(other_user)
+    following.include?(other_user)
   end
 
   private

app/views/relationships/create.js.erb

+$("#follow_form").html("<%= escape_javascript(render('users/unfollow')) %>");
+$("#followers").html('<%= @user.followers.count %>');
\ No newline at end of file

app/views/relationships/destroy.js.erb

+$("#follow_form").html("<%= escape_javascript(render('users/follow')) %>");
+$("#followers").html('<%= @user.followers.count %>');
\ No newline at end of file

app/views/shared/_stats.html.erb

+<% @user ||= current_user %>
+<div class="stats">
+  <a href="<%= following_user_path(@user)%>">
+    <strong id="following" class="stat">
+      <%= @user.following.count %>
+    </strong>
+    following
+  </a>
+  <a href="<%= followers_user_path(@user)%>">
+    <strong id="followers" class="stat">
+      <%= @user.followers.count %>
+    </strong>
+    followers
+  </a>
+</div>
\ No newline at end of file

app/views/static_pages/home.html.erb

@@ -4,6 +4,9 @@
       <section class="user_info">
         <%= render 'shared/user_info' %>
       </section>
+       <section class="stats">
+        <%= render 'shared/stats' %>
+      </section>      
       <section class="micropost_form">
         <%= render 'shared/micropost_form' %>
       </section>

app/views/users/_follow.html.erb

+<%= form_with(model: current_user.active_relationships.build, remote: true) do |f| %>
+  <div><%= hidden_field_tag :followed_id, @user.id %></div>
+  <%= f.submit "Follow", class: "btn btn-primary" %>
+<% end %>
\ No newline at end of file

app/views/users/_follow_form.html.erb

+<% unless current_user?(@user) %>
+  <div id="follow_form">
+    <% if current_user.following?(@user) %>
+      <%= render 'unfollow' %>
+    <% else %>
+      <%= render 'follow' %>
+    <% end %>
+  </div>
+<% end %>
\ No newline at end of file

app/views/users/_unfollow.html.erb

+<%= form_with(model: current_user.active_relationships.find_by(followed_id: @user.id),  
+              html: { method: :delete }, remote: true) do |f| %>
+  <%= f.submit "Unfollow", class: "btn" %>
+<% end %>
\ No newline at end of file

app/views/users/_user.html.erb

 <li>
   <%= gravatar_for user, size: 50 %>
   <%= link_to user.name, user %>
-  <% if current_user.admin? && !current_user?(user) %>
+  <%# <% if current_user.admin? && !current_user?(user) %>  
+  <% if current_user.try(:admin?) %> 
     | <%= link_to "delete", user, method: :delete,
                                   data: { confirm: "You sure?" } %>
   <% end %>                            

app/views/users/show.html.erb

@@ -8,8 +8,12 @@
         <%= @user.name %>
       </h1> 
     </section>
+    <section class="stats">
+      <%= render 'shared/stats' %>
+    </section>
   </aside>
   <div class="col-md-8">
+    <%= render 'follow_form' if logged_in? %>
     <% if @user.microposts.any? %>
       <h3>Microposts (<%= @user.microposts.count %>)</h3>
       <ol class="microposts">

app/views/users/show_follow.html.erb

+<% provide(:title, @title) %>
+<div class="row">
+  <aside class="col-md-4">
+    <section class="user_info">
+      <%= gravatar_for @user %>
+      <h1><%= @user.name %></h1>
+      <span><%= link_to "view my profile", @user %></span>
+      <span><b>Microposts:</b> <%= @user.microposts.count %></span>
+    </section>
+    <section class="stats">
+      <%= render 'shared/stats' %> 
+      <% if @users.any? %>
+        <div class="user_avatars">
+          <% @users.each do |user| %> 
+            <%= link_to gravatar_for(user, size: 30), user %> 
+          <% end %>
+        </div>
+      <% end %>
+    </section>
+  </aside>
+  <div class="col-md-8">
+    <h3><%= @title %></h3>
+      <% if @users.any? %>
+        <ul class="users follow">
+          <%= render @users %>
+        </ul>
+        <%= will_paginate %> 
+      <% end %>
+  </div>
+</div>

config/application.rb

@@ -18,5 +18,7 @@ module SampleApp
     #
     # config.time_zone = "Central Time (US & Canada)"
     # config.eager_load_paths << Rails.root.join("extras")
+    # Include the authenticity token in remote forms.
+    config.action_view.embed_authenticity_token_in_remote_forms = true
   end
 end

config/routes.rb

@@ -7,8 +7,13 @@ Rails.application.routes.draw do
   get     '/login',     to: 'sessions#new'
   post    '/login',     to: 'sessions#create'
   delete  '/logout',    to: 'sessions#destroy'
-  resources :users
+  resources :users do
+    member do
+      get :following, :followers
+    end
+  end
   resources :account_activations,   only: [:edit]
   resources :password_resets,       only: [:new, :create, :edit, :update]
   resources :microposts,            only: [:create, :destroy]
+  resources :relationships,         only: [:create, :destroy]
 end
\ No newline at end of file

db/migrate/20210622074033_create_relationships.rb

+class CreateRelationships < ActiveRecord::Migration[6.1]
+  def change
+    create_table :relationships do |t|
+      t.integer :follower_id
+      t.integer :followed_id
+
+      t.timestamps
+    end
+    add_index :relationships, :follower_id
+    add_index :relationships, :followed_id
+    add_index :relationships, [:follower_id, :followed_id], 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: 2021_06_22_061651) do
+ActiveRecord::Schema.define(version: 2021_06_22_074033) do
 
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
@@ -49,6 +49,16 @@ ActiveRecord::Schema.define(version: 2021_06_22_061651) do
     t.index ["user_id"], name: "index_microposts_on_user_id"
   end
 
+  create_table "relationships", force: :cascade do |t|
+    t.integer "follower_id"
+    t.integer "followed_id"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["followed_id"], name: "index_relationships_on_followed_id"
+    t.index ["follower_id", "followed_id"], name: "index_relationships_on_follower_id_and_followed_id", unique: true
+    t.index ["follower_id"], name: "index_relationships_on_follower_id"
+  end
+
   create_table "users", force: :cascade do |t|
     t.string "name"
     t.string "email"

db/seeds.rb

@@ -24,3 +24,11 @@ users = User.order(:created_at).take(6)
   content = Faker::Lorem.sentence(word_count: 5)
   users.each { |user| user.microposts.create!(content: content) }
 end
+
+# Create following relationships
+users = User.all
+user = users.first
+following = users[2..50]
+followers = users[3..40]
+following.each { |followed| user.follow(followed) }
+followers.each { |follower| follower.follow(user) }
\ No newline at end of file

test/controllers/relationships_controller_test.rb

+require "test_helper"
+
+class RelationshipsControllerTest < ActionDispatch::IntegrationTest
+  
+  test "create should require logged-in user" do
+    assert_no_difference 'Relationship.count' do
+      post relationships_path
+    end
+    assert_redirected_to login_url
+  end
+  
+  test "destroy should require logged-in user" do
+    assert_no_difference 'Relationship.count' do
+      delete relationship_path(relationships(:one))
+    end
+    assert_redirected_to login_url
+  end
+end

test/controllers/users_controller_test.rb

@@ -58,4 +58,13 @@ class UsersControllerTest < ActionDispatch::IntegrationTest
     assert flash.empty?
     assert_redirected_to root_url
   end
+
+  test "should redirect following when not logged in" do
+    get following_user_path(@user)
+    assert_redirected_to login_url
+  end
+  test "should redirect followers when not logged in" do
+    get followers_user_path(@user)
+    assert_redirected_to login_url
+  end
 end
\ No newline at end of file

test/fixtures/relationships.yml

+one:
+  follower: michael
+  followed: lana
+two:
+  follower: michael
+  followed: malory
+three:
+  follower: lana
+  followed: michael
+four:
+  follower: archer
+  followed: michael
\ No newline at end of file

test/integration/following_test.rb

+require "test_helper"
+
+class FollowingTest < ActionDispatch::IntegrationTest
+  def setup
+    @user = users(:michael)
+    @other = users(:archer)
+    log_in_as(@user)
+  end
+  test "following page" do
+    get following_user_path(@user)
+    assert_not @user.following.empty?
+    assert_match @user.following.count.to_s, response.body
+    @user.following.each do |user|
+      assert_select "a[href=?]", user_path(user)
+    end
+  end
+
+  test "followers page" do
+    get followers_user_path(@user)
+    assert_not @user.followers.empty?
+    assert_match @user.followers.count.to_s, response.body
+    @user.followers.each do |user|
+      assert_select "a[href=?]", user_path(user)
+    end
+  end
+
+  test "should follow a user the standard way" do
+    assert_difference '@user.following.count', 1 do
+      post relationships_path, params: { followed_id: @other.id }
+    end
+  end
+
+  test "should follow a user with Ajax" do
+    assert_difference '@user.following.count', 1 do
+      post relationships_path, xhr: true, params: { followed_id: @other.id }
+    end
+  end
+
+  test "should unfollow a user the standard way" do
+    @user.follow(@other)
+    relationship = @user.active_relationships.find_by(followed_id: @other.id)
+    assert_difference '@user.following.count', -1 do
+      delete relationship_path(relationship)
+    end
+  end
+
+  test "should unfollow a user with Ajax" do
+    @user.follow(@other)
+    relationship = @user.active_relationships.find_by(followed_id: @other.id)
+    assert_difference '@user.following.count', -1 do
+      delete relationship_path(relationship), xhr: true
+    end
+  end
+end

test/models/relationship_test.rb

+require "test_helper"
+
+class RelationshipTest < ActiveSupport::TestCase
+  def setup
+    @relationship = Relationship.new(follower_id: users(:michael).id,
+                                     followed_id: users(:archer).id)
+  end
+
+  test "should be valid" do
+    assert @relationship.valid?
+  end
+
+  test "should require a follower_id" do
+    @relationship.follower_id = nil
+    assert_not @relationship.valid?
+  end
+
+  test "should require a followed_id" do
+    @relationship.followed_id = nil
+    assert_not @relationship.valid?
+  end
+end

test/models/user_test.rb

@@ -66,4 +66,33 @@ class UserTest < ActiveSupport::TestCase
       @user.destroy
     end
   end
+
+  test "should follow and unfollow a user" do
+    michael = users(:michael)
+    archer = users(:archer)
+    assert_not michael.following?(archer)
+    michael.follow(archer)
+    assert michael.following?(archer)
+    assert archer.followers.include?(michael)
+    michael.unfollow(archer)
+    assert_not michael.following?(archer)
+  end
+
+  test "feed should have the right posts" do
+    michael = users(:michael)
+    archer  = users(:archer)
+    lana    = users(:lana)
+    # Posts from followed user
+    lana.microposts.each do |post_following|
+      assert michael.feed.include?(post_following)
+    end
+    # Posts from self
+    michael.microposts.each do |post_self|
+      assert michael.feed.include?(post_self)
+    end
+    # Posts from unfollowed user
+    archer.microposts.each do |post_unfollowed|
+      assert_not michael.feed.include?(post_unfollowed)
+    end
+  end
 end