ruby-on-rails - PUT 嵌套对象

Question

我的 Rails 5.1 API 应用程序中有如下所示的 Dish 和 Comment 模型 - 代码库 here .我需要帮助将新的 Comment 添加到 Dish。

发布

class Dish < ApplicationRecord
    has_many :comments
end

评论

class Comment < ApplicationRecord
    belongs_to :dish
end

后序列化器(使用 ActiveModel Seriazlier)

class DishSerializer < ActiveModel::Serializer
  attributes :id, :name, :image, :category, :label, :price, :featured, :description, :created_at

  has_many :comments
end

注释序列化器

class CommentSerializer < ActiveModel::Serializer
  attributes :id, :rating, :comment, :author, :date

  def date
    object.created_at
  end
end

Post Controller - 默认 rails 脚手架

class DishesController < ApplicationController
  before_action :set_dish, only: [:show, :update, :destroy]

  # GET /dishes
  def index
    @dishes = Dish.all

    render json: @dishes
  end

  # GET /dishes/1
  def show
    render json: @dish
  end

  # POST /dishes
  def create
    @dish = Dish.new(dish_params)

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

  # PATCH/PUT /dishes/1
  def update
    # byebug
    if @dish.update(dish_params)
      render json: @dish
    else
      render json: @dish.errors, status: :unprocessable_entity
    end
  end

  # DELETE /dishes/1
  def destroy
    @dish.destroy
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_dish
      @dish = Dish.find(params[:id])
    end

    # Only allow a trusted parameter "white list" through.
    def dish_params
      params.require(:dish).permit(:name, :image, :category, :label, :price, :featured, :description)
    end
end

评论 Controller - 默认 rails 脚手架

class CommentsController < ApplicationController
  before_action :set_comment, only: [:show, :update, :destroy]

  # GET /comments
  def index
    @comments = Comment.all

    render json: @comments
  end

  # GET /comments/1
  def show
    render json: @comment
  end

  # POST /comments
  def create
    @comment = Comment.new(comment_params)

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

  # PATCH/PUT /comments/1
  def update
    if @comment.update(comment_params)
      render json: @comment
    else
      render json: @comment.errors, status: :unprocessable_entity
    end
  end

  # DELETE /comments/1
  def destroy
    @comment.destroy
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_comment
      @comment = Comment.find(params[:id])
    end

    # Only allow a trusted parameter "white list" through.
    def comment_params
      params.require(:comment).permit(:rating, :comment, :author)
    end
end

问题

当用户访问 /dishes/:id 并通过前端应用程序(Angular 2)向菜品添加评论时，评论 被推送到当前评论的数组，我正在调用 PUT/dishes:id，dish 对象嵌套在现有的 comments 和新评论中。然而，新的 comment 没有被 rails 保存——没有返回错误，而是返回了 dish 对象。但是我确实在 rails s 控制台中看到了 Unpermitted parameters: :id, :created_at。如何让 Rails 保存新评论？

在 Angular 客户端，我向菜品添加评论的页面 ( dishes/9 ) 如下所示。

Rails 服务器日志

在 Rails 方面，下面是我在 params 中看到的 - 我确实看到了新评论 - {"author"=>"JANE7777", "rating"=>3, "comment"=>"COMMENT7777", "date"=>"2017-11-12T12:58:12.555Z"} 在那里。

Started PUT "/dishes/9" for 127.0.0.1 at 2017-11-12 18:28:12 +0530
Processing by DishesController#update as HTML
  Parameters: {"id"=>"9", "name"=>"Uthappizza", "image"=>"images/uthappizza.png", "category"=>"mains", "label"=>"Hot", "price"=>"4.99", "featured"=>true, "description"=>"A unique combination of Indian Uthappam (pancake) and Italian pizza, topped with Cerignola olives, ripe vine cherry tomatoes, Vidalia onion, Guntur chillies and Buffalo Paneer.", "created_at"=>"2017-11-01T04:30:09.407Z", "comments"=>[{"id"=>46, "rating"=>5, "comment"=>"Imagine all the eatables, living in conFusion!", "author"=>"John Lemon", "date"=>"2012-10-16T17:57:28.556Z"}, {"id"=>47, "rating"=>4, "comment"=>"Sends anyone to heaven, I wish I could get my mother-in-law to eat it!", "author"=>"Paul McVites", "date"=>"2014-09-05T17:57:28.556Z"}, {"id"=>48, "rating"=>3, "comment"=>"Eat it, just eat it!", "author"=>"Michael Jaikishan", "date"=>"2015-02-13T17:57:28.556Z"}, {"id"=>49, "rating"=>4, "comment"=>"Ultimate, Reaching for the stars!", "author"=>"Ringo Starry", "date"=>"2013-12-02T17:57:28.556Z"}, {"id"=>50, "rating"=>2, "comment"=>"It's your birthday, we're gonna party!", "author"=>"25 Cent", "date"=>"2011-12-02T17:57:28.556Z"}, {"id"=>51, "rating"=>4, "comment"=>"great dish", "author"=>"Jogesh", "date"=>"2017-10-30T05:03:39.656Z"}, {"author"=>"JANE7777", "rating"=>3, "comment"=>"COMMENT7777", "date"=>"2017-11-12T12:58:12.555Z"}], "dish"=>{"id"=>"9", "name"=>"Uthappizza", "image"=>"images/uthappizza.png", "category"=>"mains", "label"=>"Hot", "price"=>"4.99", "featured"=>true, "description"=>"A unique combination of Indian Uthappam (pancake) and Italian pizza, topped with Cerignola olives, ripe vine cherry tomatoes, Vidalia onion, Guntur chillies and Buffalo Paneer.", "created_at"=>"2017-11-01T04:30:09.407Z"}}
  Dish Load (1.0ms)  SELECT  "dishes".* FROM "dishes" WHERE "dishes"."id" = $1 LIMIT $2  [["id", 9], ["LIMIT", 1]]

[25, 34] in C:/apps/railsApi/app/controllers/dishes_controller.rb
   25:   end
   26:
   27:   # PATCH/PUT /dishes/1
   28:   def update
   29:     byebug
=> 30:     if @dish.update(dish_params)
   31:       render json: @dish
   32:     else
   33:       render json: @dish.errors, status: :unprocessable_entity
   34:     end
(byebug) params
<ActionController::Parameters {"id"=>"9", "name"=>"Uthappizza", "image"=>"images/uthappizza.png", "category"=>"mains", "label"=>"Hot", "price"=>"4.99", "featured"=>true, "description"=>"A unique combination of Indian Uthappam (pancake) and Italian pizza, topped with Cerignola olives, ripe vine cherry tomatoes, Vidalia onion, Guntur chillies and Buffalo Paneer.", "created_at"=>"2017-11-01T04:30:09.407Z", "comments"=>[{"id"=>46, "rating"=>5, "comment"=>"Imagine all the eatables, living in conFusion!", "author"=>"John Lemon", "date"=>"2012-10-16T17:57:28.556Z"}, {"id"=>47, "rating"=>4, "comment"=>"Sends anyone to heaven, I wish I could get my mother-in-law to eat it!", "author"=>"Paul McVites", "date"=>"2014-09-05T17:57:28.556Z"}, {"id"=>48, "rating"=>3, "comment"=>"Eat it, just eat it!", "author"=>"Michael Jaikishan", "date"=>"2015-02-13T17:57:28.556Z"}, {"id"=>49, "rating"=>4, "comment"=>"Ultimate, Reaching for the stars!", "author"=>"Ringo Starry", "date"=>"2013-12-02T17:57:28.556Z"}, {"id"=>50, "rating"=>2, "comment"=>"It's your birthday, we're gonna party!", "author"=>"25 Cent", "date"=>"2011-12-02T17:57:28.556Z"}, {"id"=>51, "rating"=>4, "comment"=>"great dish", "author"=>"Jogesh", "date"=>"2017-10-30T05:03:39.656Z"}, {"author"=>"JANE7777", "rating"=>3, "comment"=>"COMMENT7777", "date"=>"2017-11-12T12:58:12.555Z"}], "controller"=>"dishes", "action"=>"update", "dish"=>{"id"=>9, "name"=>"Uthappizza", "image"=>"images/uthappizza.png", "category"=>"mains", "label"=>"Hot", "price"=>"4.99", "featured"=>true, "description"=>"A unique combination of Indian Uthappam (pancake) and Italian pizza, topped with Cerignola olives, ripe vine cherry tomatoes, Vidalia onion, Guntur chillies and Buffalo Paneer.", "created_at"=>"2017-11-01T04:30:09.407Z"}} permitted: false>
(byebug) c
Unpermitted parameters: :id, :created_at
   (0.0ms)  BEGIN
   (0.0ms)  COMMIT
[active_model_serializers]   Comment Load (0.0ms)  SELECT "comments".* FROM "comments" WHERE "comments"."dish_id" = $1  [["dish_id", 9]]
[active_model_serializers] Rendered DishSerializer with ActiveModelSerializers::Adapter::Attributes (31.29ms)
Completed 200 OK in 1901725ms (Views: 37.5ms | ActiveRecord: 5.0ms)

客户端模型

Dish 模型的成员之一是 Comment[]。当通过表单添加新评论时，comment 被推送到 dish.comments 数组，然后再将 Dish 对象发送到 Rails API back-结束。

客户端的

评论模型

export class Comment {
    rating: number;
    comment: string;
    author: string;
    date: string;
}

在客户端发布模型

import { Comment } from './comment';
export class Dish {
  id: number;
  name: string;
  image: string;
  category: string;
  label: string;
  price: string;
  featured: boolean;
  description: string;
  comments: Comment[];
}

Answer 1

我建议您使用 Comments Controller 并形成一个嵌套路由以实现 RESTful。

首先，POST 请求，包括 dish_id 到/comments。您正在尝试创建评论，而不是更新菜肴。

其次，形成嵌套路由:/菜品/:dish_id/comments

这是嵌套资源的指南:http://guides.rubyonrails.org/routing.html#nested-resources

您出错的原因是您破坏了预期的参数结构。对于 PUT，您的参数应该是:

{
   id: <record to update>,
   dish: {
      name: “blah”,
      comments: [{...},{...}]
   }
 }

再次强调，如果您只想添加评论，我强烈建议您不要 PUT 到 Dish。例如:上面的内容需要替换所有关于 Dish 的评论!如果您要创建记录，请创建该记录，不要更新它的父级。

如果您想在添加新评论时更新 Dish，您可以在创建时向评论模型添加回调，或在评论创建 Controller 操作中执行此操作。