让omniauth模拟rails中请求规范的登录

gem 'omniauth'

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook, 'APP_ID', 'APP_SECRET'
end

<%= link_to "使用Facebook登录", user_omniauth_authorize_path(:facebook) %>

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

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def facebook
    @user = User.from_omniauth(request.env["omniauth.auth"])
    if @user.persisted?
      sign_in_and_redirect @user, event: :authentication
    else
      session["devise.facebook_data"] = request.env["omniauth.auth"]
      redirect_to new_user_registration_url
    end
  end
end