Question

当我执行Object.to_json时，Mongoid不会将子文档包含到JSON中。我该怎么做？我试过这个：

@realty = Realty.includes(:comments).find(params[:id])
...
respond_to do |format|
  format.json  { render json: @realty }
end

但是评论仍未包含在JSON中。

Answer 1

你需要在to_json调用中使用：include

@realty = Realty.find(params[:id])
...
respond_to do |format|
  format.json  { render json: @realty.to_json(include: [:comments]) }
end

您可以在其中包含任何关联。

您也可以使用任何随机方法：

@foo.to_json(methods: [:some_arbitrary_method])

这适用于较小/简单的api但请查看：
JBuilder，它是Rails 4默认gem包含的一部分，显然你可以在任何Rails版本中使用它 ActiveModel Serializers

Answer 2

我正在做类似这样的事情，我使用：

gem "active_model_serializers"

https://github.com/rails-api/active_model_serializers

http://railscasts.com/episodes/409-active-model-serializers

在我的案例Project has_many :posts中，json结果将是：

{"projects":[{"id":1,"title":"test project","description":"nice test project","slug":null,"posts":[{"id":1,"title":"new test post for test project","body":"Some content here and there","responses":[],"author":{"id":1,"email":"admin@mail.md"}}],"members":[]}]}

class ProjectSerializer < ActiveModel::Serializer
  attributes :id, :title, :description, :slug
  has_many :posts
  has_many :memberships, key: :members
end

class PostSerializer < ActiveModel::Serializer
  attributes :id, :title, :body, :responses
end

Mongoid：Object.to_json - 如何加载子对象？

2 个答案: