rodloboz

resources :users, path: '/', param: :username, only: %i[show] do
  post :follow, to: 'users/follows#create', as: :follow
  delete :follow, to: 'users/follows#destroy', as: :unfollow
end

rodloboz

class CreateFollows < ActiveRecord::Migration[6.0]
  def change
    create_table 'follows' do |t|
      t.integer 'following_id', null: false
      t.integer 'follower_id', null: false

      t.timestamps null: false
    end

    add_index :follows, :following_id

rodloboz

# app/models/user.rb

def self.find_for_database_authentication(warden_conditions)
  conditions = warden_conditions.dup
  login = conditions.delete(:login)
  where(conditions).where(["lower(username) = :value OR lower(email) = :value", {value: login.strip.downcase}]).first
end

rodloboz

module AvatarHelper
  def avatar_url(user)
    if gravatar?(user)
      gravatar = Digest::MD5::hexdigest(user.email).downcase
      "http://gravatar.com/avatar/#{gravatar}.png?s=200"
    else
      'default_avatar.png'
    end
  end

rodloboz

class ApplicationController < ActionController::Base
  # ...
  
  before_action :configure_permitted_parameters, if: :devise_controller?

  protected

  def configure_permitted_parameters
    devise_parameter_sanitizer.permit(:sign_up, keys: [:email, :password, :username, :full_name])
    devise_parameter_sanitizer.permit(:sign_in, keys: [:email, :password, :username])

rodloboz

class AddAttributesToUsers < ActiveRecord::Migration[6.0]
  def change
    add_column :users, :full_name, :string
    add_column :users, :username, :string
    add_index :users, :username, unique: true
    add_column :users, :about, :text
  end
end

rodloboz

import { Controller } from 'stimulus';

export default class extends Controller {
  static targets = [ 'followerCount', 'followerMessage' ]

  connect() {
    this.update();
  };

  update() {

rodloboz

<div id="follow-btn">
  <% if current_user.is_following?(user) %>
    <%= link_to user_unfollow_path(user.username), method: :delete,
                                                   data: {
                                                     action: 'ajax:success->follow#update'
                                                    },
                                                   remote: true do
    %>
      <button class="btn btn-blue ml-4">Unfollow</button>
    <% end %>

rodloboz

<li class="mr-8">
  <span id="followers-count"
        class="font-bold"
        data-target="follow-button.followerCount"><%= @user.followers_count %></span>&nbsp
  <span data-target="follow-button.followerMessage"></span>
</li>

rodloboz

class Follow < ApplicationRecord
  belongs_to :follower, class_name: 'User', foreign_key: 'follower_id',
                        counter_cache: :followings_count,
                        inverse_of: :following_relationships
  belongs_to :following, class_name: 'User', foreign_key: 'following_id',
                         counter_cache: :followers_count,
                         inverse_of: :follower_relationships
end