Rails 6 API仅不保存嵌套属性

问题描述

我有一个Rails 6应用程序，该应用程序仅在API模式下作为移动应用程序的后端提供程序。

我有两个模型Offer和ServiceContent

class Offer < ApplicationRecord
  belongs_to :user
  has_many :service_contents
  accepts_nested_attributes_for :service_contents,allow_destroy: true

  #..... much more stuff below here
end

class ServiceContent < ApplicationRecord
  belongs_to :offer
end

我的OffersController看起来像这样：

# frozen_string_literal: true

class OffersController < ApplicationController
  before_action :set_offer,only: %i[show update destroy]
  before_action :authenticate_user,only: %i[create show update destroy]

 
  def new
    @offer = Offer.new
    @offer.service_contents.build
  end
  

  # POST /offers
  # POST /offers.json
  def create
    @offer = Offer.new(offer_params)


    if @offer.save
      render :show,status: :created,location: @offer
    else
      render json: @offer.errors,status: :unprocessable_entity
    end
  end

  # PATCH/PUT /offers/1
  # PATCH/PUT /offers/1.json
  def update
    if @offer.update(offer_params)
      render :show,status: :ok,status: :unprocessable_entity
    end
  end

  # DELETE /offers/1
  # DELETE /offers/1.json
  def destroy
    @offer.destroy
  end


  private


  # Use callbacks to share common setup or constraints between actions.
  def set_offer
    @offer = Offer.find(params[:id])
  end

  # Never trust parameters from the scary internet,only allow the white list through.
  def offer_params
    params.require(:offer).permit(:id,:from,:to,:departure_datetime,:return_datetime,service_contents_attributes: [:name,:icon_id,:data]
                                  )

    # params.fetch(:offer,{})
  end


end

当我想通过邮递员创建这个问题时会出现问题。

我的JSON看起来像这样：

{
    "from": "Maroco,Maroco","to": "Zagreb,Croatia","departure_datetime": "2020-09-05 14:32:45 +0200","user_id": 1,"service_contents": [
        {
            "name": "test","icon_id": 1,"data": null
        },{
            "name": "itd","icon_id": 2,"data": 0
        }
    ]
}

我通过POST方法发送数据，显然可以通过参数，但是ServiceContent始终创建为空数组。

Started POST "/offers/" for ::1 at 2020-09-05 14:52:56 +0200
Processing by OffersController#create as */*
  Parameters: {"from"=>"Maroco,"to"=>"Zagreb,"departure_datetime"=>"2020-09-05 14:32:45 +0200","user_id"=>1,"service_contents"=>[{"name"=>"test","icon_id"=>1,"data"=>nil},{"name"=>"itd","icon_id"=>2,"data"=>0}],"offer"=>{"from"=>"Maroco,"user_id"=>1}}
  User Load (0.4ms)  SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id",1],["LIMIT",1]]
  ↳ app/controllers/application_controller.rb:21:in `refresh_bearer_auth_header'
  CACHE User Load (0.0ms)  SELECT "users".* FROM "users" WHERE "users"."id" = $1 LIMIT $2  [["id",1]]
  ↳ app/controllers/offers_controller.rb:34:in `create'
  TRANSACTION (0.1ms)  BEGIN
  ↳ app/controllers/offers_controller.rb:34:in `create'
  Offer Create (0.6ms)  INSERT INTO "offers" ("from","to","departure_datetime","user_id","created_at","updated_at","offer_type_icon") VALUES ($1,$2,$3,$4,$5,$6,$7) RETURNING "id"  [["from","Maroco,Maroco"],["to","Zagreb,Croatia"],["departure_datetime","2020-09-05 12:32:45"],["user_id",["created_at","2020-09-05 12:52:56.689955"],["updated_at",["offer_type_icon",2]]
  ↳ app/controllers/offers_controller.rb:34:in `create'
  TRANSACTION (0.9ms)  COMMIT
  ↳ app/controllers/offers_controller.rb:34:in `create'
  Rendering offers/show.json.jbuilder
  ServiceContent Load (0.3ms)  SELECT "service_contents".* FROM "service_contents" WHERE "service_contents"."offer_id" = $1  [["offer_id",6]]
  ↳ app/views/offers/_offer.json.jbuilder:10
  Rendered offers/_offer.json.jbuilder (Duration: 7.9ms | Allocations: 2087)
  Rendered offers/show.json.jbuilder (Duration: 8.7ms | Allocations: 2234)
Completed 201 Created in 66ms (Views: 10.2ms | ActiveRecord: 19.7ms | Allocations: 19234)

自从收到响应后，它显然可以将内容保存到数据库：

{
    "id": 6,"from": "Maroco,"departure_date": "2020-09-05","departure_time": "12:32","offer_type_icon": 2,"service_contents": []
}

但是正如我所说，service_contents始终是一个空数组。

感谢您的帮助。

解决方法

好吧，我实际上找到了答案。

感谢@dbugger指出正确的方向。

在检查了jbuilder之后，我发现这不是真正的问题。

在发送嵌套参数时，Rails希望它们在名称前总是加上_attributes-> https://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html

所以代替：

{
    "from": "Maroco,Maroco","to": "Zagreb,Croatia","departure_datetime": "2020-09-05 14:32:45 +0200","user_id": 1,"service_contents": [
        {
            "name": "test","icon_id": 1,"data": null
        },{
            "name": "itd","icon_id": 2,"data": 0
        }
    ]
}

这需要具备：

{
    "from": "Maroco,"service_contents_attributes": [
        {
            "name": "test","data": 0
        }
    ]
}

通过这种方式，它可以正常创建内容并将其保存到数据库中。

希望这会在将来使人们免于头痛。