Question

我一直在收到关于这个基本问题的各种相互矛盾的信息，答案对我目前的问题非常重要。因此，非常简单，在Rails 3中，允许或不允许将accepts_nested_attributes_for与belongs_to关系一起使用吗？

class User < ActiveRecord::Base
  belongs_to :organization
  accepts_nested_attributes_for :organization
end

class Organization < ActiveRecord::Base
  has_many :users
end

在视图中：

= form_for @user do |f|
  f.label :name, "Name"
  f.input :name

  = f.fields_for :organization do |o|
    o.label :city, "City"
    o.input :city

  f.submit "Submit"

Answer 1

从Rails 4开始，嵌套属性似乎适用于belongs_to关联。它可能在早期版本的Rails中已经更改，但我在4.0.4中进行了测试，它确实按预期工作。

Answer 2

doc epochwolf在第一行中引用了状态“嵌套属性允许您保存相关记录的属性通过父。” （我的重点）。

您可能对this other SO question which is along the same lines as this one感兴趣。它描述了两种可能的解决方案：1）将accepts_nested_attributes移动到关系的另一端（在本例中为Organization），或2）using the build method以在呈现表单之前在User中构建组织。

如果你愿意处理一些额外的代码，我还找到了一个描述a potential solution for using accepts_nested_attributes with a belongs_to relationship的要点。这也使用build方法。

Answer 3

对于Rails 3.2中的belongs_to关联，嵌套模型需要以下两个步骤：

（1）将新的attr_accessible添加到您的子模型（用户模型）。

accepts_nested_attributes_for :organization
attr_accessible :organization_attributes

（2）将@user.build_organization添加到子控制器（用户控制器）以创建列organization。

def new
  @user = User.new
  @user.build_organization
end

Answer 4

For Ruby on Rails 5.2.1

class User < ActiveRecord::Base
  belongs_to :organization
  accepts_nested_attributes_for :organization
end

class Organization < ActiveRecord::Base
  has_many :users
end

Just got to your controller, suppose to be "users_controller.rb":

Class UsersController < ApplicationController

    def new
        @user = User.new
        @user.build_organization
    end
end

And the view just as Nick did:

= form_for @user do |f|
  f.label :name, "Name"
  f.input :name

  = f.fields_for :organization do |o|
    o.label :city, "City"
    o.input :city

  f.submit "Submit"

At end we see that @user3551164 have already solved, but now (Ruby on Rails 5.2.1) we don't need the attr_accessible :organization_attributes

accepts_nested_attributes_for是否适用于belongs_to？

4 个答案: