ruby on Rails 中未从 Twitter 获取“omniauth-twitter”电子邮件 ID

标题：在Ruby on Rails中使用omniauth-twitter获取用户电子邮件ID

ruby
# Gemfile
gem 'omniauth-twitter'

ruby
# config/initializers/omniauth.rb
Rails.application.config.middleware.use OmniAuth::Builder do
  provider :twitter, 'YOUR_TWITTER_API_KEY', 'YOUR_TWITTER_API_SECRET'
end

ruby
class SessionsController < ApplicationController
  def create
    auth = request.env['omniauth.auth']
    user = User.find_or_create_by(uid: auth['uid']) do |u|
      u.name = auth['info']['name']
      u.email = auth['info']['email']
    end
    session[:user_id] = user.id
    redirect_to root_path, notice: '登录成功！'
  end
  def destroy
    session[:user_id] = nil
    redirect_to root_path, notice: '已注销！'
  end
end

ruby
# config/routes.rb
Rails.application.routes.draw do
  get '/auth/:provider/callback', to: 'sessions#create'
  get '/logout', to: 'sessions#destroy'
  # ...
end