active_record-acts_as gem 多次更新 created_at

Question

我正在创建一个 Rails 5.2 电子商务应用程序。我正在使用 active_record-acts_as gem 来模拟多 table 继承，它有一个名为 Product 的父 class 和多个子 classes (Book、Clothing、Electronic...等）都充当 Product（它们继承了 Product 的所有属性和方法）。

每个产品只能在 Category 的上下文中创建，它对应于产品的子class 名称。为了视觉效果，这是我当前的 ProductsController...

class ProductsController < ApplicationController
  before_action :set_category, only: [:new, :create]
  before_action :set_product_type, only: [:new, :create]
  before_action :set_product, only: [:show, :edit, :destroy]

  def show
    authorize @product
  end

  def new
    @product = Product.new(actable: @product_type.new)
    authorize @product
  end

  def create
    @product = @product_type.new product_params
    authorize @product

    @product.category = @category
    @product.user = current_user

    if @product.save 
      redirect_to product_path @product.slug
    else
      render :new
    end
  end

  def edit
    @product = Product.friendly.find(params[:id])
    authorize @product

    @category = @product.category
    set_product_type
  end

  def update
    @product = Product.friendly.find(params[:id])
    authorize @product

    @category = @product.category
    set_product_type

    if @product.update product_params
      redirect_to product_path @product.slug
    else
      render :edit
    end
  end

  def destroy
    authorize @product
    @category = @product.category

    if @product.destroy
      redirect_to category_path(@category)
    else
      redirect_to request.referrer
    end
  end

  private

  def set_category
    @category = Category.friendly.find(params[:category_id])
  end

  def set_product
    # specific comes from active_record_acts-as gem
    @product = Product.friendly.find(params[:id]).specific
  end

  def set_product_type
    @product_type = @category.name.singularize.capitalize.constantize
  end

  def product_params
    params.require(:product).permit(:name, :description, :price_cents, :main_image, actable_attributes: (@product_type.permitted_params))
  end
end

目前一切正常。但是，我不得不根据将其添加到产品模型中，尽管我将其修改为使用 update 而不是 new，以更正我的特定问题。

ACTABLE_TYPES = %w(Book Supply Electronic etc...)

def build_actable(params)
  raise "Unknown actable_type: #{actable_type}" unless ACTABLE_TYPES.include?(actable_type)
  self.actable.update(params)
end

如果不包含 build_actable 方法，则创建操作有效，但更新操作无效。当我尝试更新产品（产品的子 class）时没有 build_actable 的错误是...

Cannot build association actable. Are you trying to build a polymorphic one-to-one association?

主要问题

虽然我当前的控制器和build_actable方法"works"，但每次我更新产品属性时，它都会更新updated_at三次...这是日志输出...

Book Load (0.7ms)  SELECT  "books".* FROM "books" WHERE "books"."id" =  LIMIT   [["id", 13], ["LIMIT", 1]]
  ↳ app/controllers/products_controller.rb:45
  Product Update (1.0ms)  UPDATE "products" SET "name" = , "updated_at" =  WHERE "products"."id" =   [["name", "Where Angels Fear to Tread something else "], ["updated_at", "2018-07-26 03:28:30.414635"], ["id", 13]]
  ↳ app/models/product.rb:22
  Product Update (0.7ms)  UPDATE "products" SET "updated_at" =  WHERE "products"."id" =   [["updated_at", "2018-07-26 03:28:30.417622"], ["id", 13]]
  ↳ app/models/product.rb:22
  Product Update (0.5ms)  UPDATE "products" SET "updated_at" =  WHERE "products"."id" =   [["updated_at", "2018-07-26 03:28:30.420007"], ["id", 13]]
  ↳ app/models/product.rb:22
   (5.0ms)  COMMIT

我的控制器当然应该重构...但是为什么它更新了 updated_at 3 次？？？

注意：我试过直接调用 build_actable 而不是在控制器中更新...但它做同样的事情。我还从 Product 的 subclasses 中删除了时间戳。我觉得我错过了一些明显的东西....

Answer 1

我能够通过将 touch: false 添加到作为产品子类中的关联的行为来更正两次更新时间戳的问题...

acts_as :product, touch: false

active_record-acts_as gem 多次更新 created_at

active_record-acts_as gem updating created_at multiple times

ruby-on-rails

ruby-on-rails-5.2