如何在控制器中使用 as_json 到 return 模型的方法 display_name？

Question

在我的用户模型中，我有一个方法display_name来输出用户的全名。

user.rb (id, first_name, last_name, email, ...)
  def display_name
    [first_name, last_name].compact.join(' ')
  end

我正在尝试让我的控制器像这样 return display_name：

  def show
    json_response({
      user: user.as_json(only: [:id, :display_name, :email])
    })
  end

问题是，控制器只发送 ID 和电子邮件，而不是 display_name..我做错了什么？

Answer 1

根据 docs:

To include the result of some method calls on the model use :methods:

user.as_json(methods: :permalink)
# => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
#      "created_at" => "2006/08/01", "awesome" => true,
#      "permalink" => "1-konata-izumi" }

另外：

The option include_root_in_json controls the top-level behavior of as_json. If true, as_json will emit a single root node named after the object’s type. The default value for include_root_in_json option is false.

user = User.find(1)
user.as_json
# => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
#     "created_at" => "2006/08/01", "awesome" => true}

ActiveRecord::Base.include_root_in_json = true

user.as_json
# => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
#                  "created_at" => "2006/08/01", "awesome" => true } }

This behavior can also be achieved by setting the :root option to true as in:

user = User.find(1)
user.as_json(root: true)
# => { "user" => { "id" => 1, "name" => "Konata Izumi", "age" => 16,
#                  "created_at" => "2006/08/01", "awesome" => true } }

所以，大概是这样的：

user.as_json(only: [:id, :email], methods: :display_name, root: true)

Answer 2

你可以这样做：

user.as_json(only: [:id, :email], methods: [:display_name])

或

user.as_json(only: [:id, :email]).merge({'display_name': user.display_name})

或者有一个序列化器

如何在控制器中使用 as_json 到 return 模型的方法 display_name？

How to use as_json in a controller to return a model's method display_name?

activerecord

ruby-on-rails

activemodel

ruby-on-rails-5