Rails API：将对象数组添加到json返回

Question

我正在使用 Rails 5 的内置 API。

我正在学习使用 Rails 编写 API，我正在尝试弄清楚如何向我的 json 返回添加一个属性，该属性是一个对象数组。

我有一个用户和帖子的模型。

我想做的是返回与用户相关的所有帖子。

我所做的是在 posts_controller.rb 中我有一个方法可以从 URL 获取用户 ID 并返回如下所示的 json：

[{"id":1,"content":"My first post!","user":{"id":1,"firstname":"Jody","lastname":"White","email":"t@t.com","fullname_firstname_first":"Jody White"}},{"id":2,"content":"Rails School is awesome!","user":{"id":1,"firstname":"Jody","lastname":"White","email":"t@t.com","fullname_firstname_first":"Jody White"}}]

但我想要返回的是这样的：

{
    firstname: "Jody",
    lastname: "White",
    email: "whatever",
    posts: [{
        "id":1,"content":"My first post!"
        },
        {
            "id":2,"content":"Rails School is awesome!"
        }
    ]
}

我如何才能或者我可以让数据以这样的方式返回？

user.rb 模型

class User < ApplicationRecord
  attr_accessor :fullname_firstname_first

  has_many :posts

  def fullname_firstname_first
    fullname_firstname_first = firstname + " " + lastname
  end
end

post.rb 模型

class Post < ApplicationRecord
  belongs_to :user
end

users_controller.rb

class UsersController < ApplicationController
  before_action :set_user, only: [:show, :update, :destroy]

  # GET /users
  def index
    @users = User.all
    render json: @users, include: :posts
  end

  # GET /users/1
  def show
    @user = User.find(params[:id])
    render json: @user, include: :posts
  end
end

Answer 1

假设你定义了这个结构：

class Post < ApplicationRecord
  belongs_to :user
end

class User < ApplicationRecord
  has_many :posts
end

您可以使用 Active Record 序列化方法to_json 实现您想要的结构。使用将在控制器中的 respond_to 块中。

format.json { render json: @users, include: :posts }

所以你的UsersController 看起来像这样：

class UsersController < ApplicationController
  def index
    # all users with all their posts 
    @users = User.all
    respond_to do |format|
      format.json { render json: @users, include: :posts }
    end
  end

  def show
    # single user and their posts
    @user = User.find(params[:id])
    respond_to do |format|
      format.json { render json: @user, include: :posts }
    end
  end
end

更新

除了使用repond_to 块，您还可以使用：

render json: @users, include: :posts

您的控制器将如下所示：

class UsersController < ApplicationController
  def index
    # all users with all their posts 
    @users = User.all
    render json: @users, include: :posts
  end

  def show
    # single user and their posts
    @user = User.find(params[:id])
    render json: @user, include: :posts
  end
end