[RUBY] I touched the devise controller that I felt in the black box

Introduction

devise is a gem that makes it easy to implement user management functions. Because it made it easy, there were many parts where I didn't understand "why it works". I'm creating an original application, I want to change the specifications, and after a lot of trial and error, I feel that I've learned how to use devise more than before.

devise controller

When I first learned about devise, I didn't deal with controllers at all. For devise, the routing was generated without permission, and the controller didn't even exist, even though other functions were implemented with the MVC model in mind. Since Rails is singing the MVC model, I've been learning with the idea of "I wonder if there is a controller, but I wonder if it's disappearing." When I check the command in the terminal,

rails g --help

=>
Devise:
  devise
  devise:controllers
  devise:install
  devise:views

I noticed that devise can generate a controller.

Until now if you didn't use the devise controller

The strong parameter was set in application_controller.rb. This file is inherited by all controllers, so it also applies to devise's controllers. To avoid interfering with controllers other than devise

application_controller.rb

before_action :configure_permitted_parameters, if: :devise_controller?

 private
 def configure_permitted_parameters
   devise_parameter_sanitizer.permit(:sign_up, keys: [:Column name])
 end

I wrote that, and only when using the devise controller with devise_controller ?, the processing of the strong parameter was done.

Background

In the application I'm currently writing, I'm wondering if I can change the user's sign-in to "nickname" </ font> and "password" instead of authenticating with "email address" and "password". It was.

rails g devise:controllers user

config.authentication_keys = [:nickname]

class Users::SessionsController < Devise::SessionsController
  before_action :configure_sign_in_params, only: [:create] #Uncomment
(Omission)
protected #Uncomment
# If you have extra params to permit, append them to the sanitizer.
def configure_sign_in_params #Uncomment
    devise_parameter_sanitizer.permit(:sign_in, keys: [:nickname, :password]) #Uncomment and describe the column you want to use for authentication in square brackets * Also describe password here
end #Uncomment

devise_for :users, controllers: {sessions: 'users/sessions'}

<%= form_with model: @user, url: user_session_path, class: 'sessions-main', local: true do |f| %>
  <%= f.text_field :nickname, class:"nickname", id:"nickname", placeholder:"nickname" %>
  <%= f.password_field :password, class:"input-default", id:"password", placeholder:"6 or more single-byte alphanumeric characters" %>
  <%= f.submit "log in", class:"reg-btn" %>
<% end %>