Rails 4-通过has_many创建记录

Question

In my project i have something like this:

class User < ActiveRecord::Base
  has_many  :roles
  has_many  :websites, through: :roles
end

class Website < ActiveRecord::Base
  validates                 :name, presence: true
  has_many                  :roles
  has_many                  :users, through: :roles
end

class Role < ActiveRecord::Base
  validates :name, presence: true
  belongs_to :user
  belongs_to :website
end

So when I try to do:

User.first.websites.create(name: "First")

I have this error

ActiveRecord::RecordInvalid: Validation failed: Name can't be blank

How can i create a new User Website in one line?

Answer 1

我认为，如果您从role模型中删除validates :name, presence: true ，那么它将起作用。

Answer 2

The validation error is actually coming from the Role model, which also has validation for the name attribute.

You can do it in one line by creating the website through the role, using accepts_nested_attributes_for :

class Role < ActiveRecord::Base
  validates :name, presence: true
  belongs_to :user
  belongs_to :website

  accepts_nested_attributes_for :website
end

User.first.roles.create(name: "Role name", website_attributes: { name: "Website name" })