[RUBY] Super easy in 2 steps! How to install devise! !! (rails 5 version)

Hello! In this first post, I'll show you how to implement the login feature using devise. I would like to explain the flow from installation to actual display and login.

What is devise

What is devise in the first place? devise is a gem that can easily implement login function, user registration function, etc. In the initial state, you can log in and sign up by setting ** email and password **. It is a gem that you definitely want to use when you want to implement the membership function!

Step 1: Install devise

First, let's install devise.

Write "gem'devise'" at the bottom of the Gemfile.

Gemfile

gem 'devise'

Let the application load the added gem. Type the following in the terminal.

$ bundle install

Then make the initial settings for devise.

$ rails g devise:install

Installation is successful if the following message is displayed!

Step 2: Display the login screen

Now let's actually display the login screen. This time, we will create a user table in the database to store user information. The table name is "User". Type the following into your terminal:

$ rails g devise User

Originally, if you want to create a table from scratch, you need to create a column along with the table, but if you use devise, ** user table and column will be created automatically **. Let's check the migration file that was actually created.

db/migrate/(Year, month, day, hour, minute, second)_devise_create_users.rb

class DeviseCreateUsers < ActiveRecord::Migration[5.2]
  def change
    create_table :users do |t|
      ## Database authenticatable
      t.string :email,              null: false, default: "" #mail address
      t.string :encrypted_password, null: false, default: "" #password

      ## Recoverable
      t.string   :reset_password_token
      t.datetime :reset_password_sent_at

      ## Rememberable
      t.datetime :remember_created_at

      ## Trackable
      # t.integer  :sign_in_count, default: 0, null: false
      # t.datetime :current_sign_in_at
      # t.datetime :last_sign_in_at
      # t.string   :current_sign_in_ip
      # t.string   :last_sign_in_ip

      ## Confirmable
      # t.string   :confirmation_token
      # t.datetime :confirmed_at
      # t.datetime :confirmation_sent_at
      # t.string   :unconfirmed_email # Only if using reconfirmable

      ## Lockable
      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
      # t.string   :unlock_token # Only if unlock strategy is :email or :both
      # t.datetime :locked_at


      t.timestamps null: false
    end

    add_index :users, :email,                unique: true
    add_index :users, :reset_password_token, unique: true
    # add_index :users, :confirmation_token,   unique: true
    # add_index :users, :unlock_token,         unique: true
  end
end

The columns required for the login function are an email address and password. The email address is on the line t.string: email, ……, and the password is on the line t.string: encrypted_password, …….

Once confirmed, migrate this file to the database.

$ rails db:migrate

If you do so far, you are ready! Finally, let's display it in the browser.

Start the server with rails s and enter ** "/ users / sign_in" ** after the URL to open the login screen. It should look like this. Then enter ** "/ users / sign_up" ** after the URL to open the sign-up screen.

If this display is displayed, it is complete. After that, let's rewrite as you like and create an original site! 　 Until the end Thank you for reading! I would like to write more detailed articles and advanced contents in the future, so I would be grateful if you could read it. I also do Twitter. We also send out daily tweets and information on rare occasions, so please follow us ☺️ → @saketi_sei