ruby-on-rails - first_or_create 通过电子邮件然后保存嵌套模型

Question

我的两个模型User和Submission如下:

class User < ActiveRecord::Base
  # Associations
  has_many :submissions
  accepts_nested_attributes_for :submissions

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :name, :role, :submission_ids, :quotation_ids, :submissions_attributes

  validates :email, :presence => {:message => "Please enter a valid email address" }
  validates :email, :uniqueness => { :case_sensitive => false }
end

class Submission < ActiveRecord::Base
  belongs_to :user
  attr_accessible :due_date, :text, :title, :word_count, :work_type, :rush, :user, :notes

  validates :work_type, :title, :text,:presence => true
  validates :text, :length => { :minimum => 250 }
  validates :word_count, :numericality => { :only_integer => true }
end

我有一个表格可以收集这两个模型所需的数据。用户 Controller :

def index
  @user = User.new
  @user.submissions.build
end

def create
  @user = User.where(:email => params[:user][:email]).first_or_create(params[:user])

  if @user
    redirect_to :root
  else
    render 'pages/index'
  end
end

我想做的是首先通过提交的电子邮件检查用户是否已经存在于系统中。如果是这样，那么我想为该用户创建一个提交。否则同时创建用户和提交。

我对如何使用 first_or_create 方法做到这一点感到困惑。

感谢任何帮助。

Answer 1

first_or_create accepts a block .所以你可以这样做:

@user = User.where(:email => params[:user][:email]).first_or_create do |user|
  # This block is called with a new user object with only :email set
  # Customize this object to your will
  user.attributes = params[:user]
  # After this, first_or_create will call user.create, so you don't have to
end