Rails json包含两个相同模型的实例。

Question

我有一个名为Exchange的模型，它存储创建它的用户的user_id。我可以调用@exchange.user，它返回User.where(user_id: @exchange.user_id)

还有一个关联可以显示所有喜欢使用Exchange的用户，这可以用@exchange.favorite_users调用

我想在json响应中返回这两种情况，但只返回第一个。

@exchanges = Exchange.includes(:tags, :favorite_users, :user).where(approved: true)

 respond_to do |format|
   format.json { render json: {data: {exchanges: @exchanges.to_json(include: [:tags, user: {:only => [:id,:slug], :methods => [:avatar_url]}, favorite_users: { only: [:id]}] ), tags: @tags.to_json }}}
 end

此版本返回user: {:only => [:id,:slug], :methods => [:avatar_url]}，但不返回favorite_users: { only: [:id]}。

format.json { render json: {data: {exchanges: @exchanges.to_json(include: [:tags, favorite_users: { only: [:id]}, user: {:only => [:id,:slug], :methods => [:avatar_url]}] ), tags: @tags.to_json }}}

这个只返回favorite_users: { only: [:id]}，但不返回user: {:only => [:id,:slug], :methods => [:avatar_url]}

我怎么把这两样都还回去呢？

交换模型

class Exchange < ApplicationRecord
  belongs_to :language
  belongs_to :user
  has_many :exchanges_users
  has_many :favorite_users, :through => :exchanges_users, source: :user
  has_many :tags_exchanges
  has_many :tags, :through => :tags_exchanges
end

Answer 1

@exchanges.to_json(include: [
    :tags, 
    {user: {only: [:id,:slug], methods: [:avatar_url]}}, 
    {favorite_users: { only: [:id]}}
])

如果要返回两个关联模型，请使用{}包装关联。

Braket只使用关联符号，但不能使用选项