讓 Rails 支援 API 登入

Step 1 : 安裝 Devise

• rails g devise:install
• rails g devise user
• rake db:migrate

Step 2 : 新增認證 Token 到 user

• rails g migration AddAuthTokenToUsers

class AddAuthTokenToUsers < ActiveRecord::Migration[5.0]
  def change
    add_column :users, :authentication_token, :string
    add_index :users, :authentication_token
  end
end

• rake db:migrate

Step 3 : 修改 user model

class User < ApplicationRecord
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable
  before_save do
    if authentication_token.blank?
      self.authentication_token = generate_authentication_token
    end
  end
  def generate_authentication_token
    loop do
      token = Devise.friendly_token
      break token unless User.where(authentication_token: token).first
    end
  end
end

Step 4 : 修改 application_controller 關掉 CSRF

class ApplicationController < ActionController::Base
  protect_from_forgery with: :null_session
  before_action :authenticate_user_from_token!
  def authenticate_user_from_token!
    authenticate_with_http_token do |token, options|
      user = User.find_by(email: options.fetch(:email))
      if user && Devise.secure_compare(user.authentication_token, token)
        sign_in user, store: false
      end
    end
  end
end

Step 5 : 使用客製 sessions_controller

• rails g controller sessions

class SessionsController < Devise::SessionsController
  respond_to :json
  def create
    super do |user|
      data = {
        token: user.authentication_token,
        email: user.email
      }
      render(json: data, status: 201) && return
    end
  end
end

Step 6 : 修改 config/routes.rb

Rails.application.routes.draw do
  devise_for :users, controllers: { sessions: "sessions" }
  # .....
end