[Rails] devise

The other day, I introduced devise with the implementation of login authentication, so I will keep a record.

What is devise

A gem package for introducing the login authentication function. You can easily implement sign-in, sign-out, sign-up (email authentication is possible), etc.

I will explain the actual usage.

Installation

Install devise. Add to Gemfile and execute bundle install.

`Gemfile`


gem 'devise'

$ bundle install

After the installation is complete, create the file. Running rails g devise: install will create the related files.

$ rails g devise:install

When executed, it will be displayed like this.

1. Ensure you have defined default url options in your environments files. Here
is an example of default_url_options appropriate for a development environment
in config/environments/development.rb:

config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }

In production, :host should be set to the actual host of your application.

2. Ensure you have defined root_url to *something* in your config/routes.rb.
For example:

root to: "home#index"

3. Ensure you have flash messages in app/views/layouts/application.html.erb.
For example:

<p class="notice"><%= notice %></p>
<p class="alert"><%= alert %></p>

4. You can copy Devise views (for customization) to your app by running:

rails g devise:views

To summarize briefly

URL setting
Routing settings
Display notifications and alerts
You can copy the devise view file and customize it.

For the time being, let's display the notification and alert messages of 3. In ʻapplication.html.erb

<%= notice %>

Added

<% = alert%> </ p>`.

`ruby:application.html.erb`


<!DOCTYPE html>
<html>
  <head>
    <title>App</title>
    <%= csrf_meta_tags %>
    <%= csp_meta_tag %>

    <%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>
  </head>

  <body>
    <p class="notice"><%= notice %></p>
    <p class="alert"><%= alert %></p>
    <%= yield %>
  </body>
</html>

Creating an authentication model

Create an authentication model and migration file with rails g devise model name.

$ rails g devise user

After creating the model and migration file, run rails db: migrate.

$ rails db:migrate

That's it. You can now use the authentication function using devise.

When editing the view file

$ rails g device:views

Doing this creates a view that you can edit as needed.