I'm creating a Rails 5.2 e-commerce application. I am using the active_record-acts_as gem to simulate multi-table inheritance that has a parent class named Product and multiple subclasses (Book, Clothing, Electronic...etc) that all act as a Product (they inherit all of Product's attributes and methods).
Each Product can only be created in the context of a Category, which corresponds to the names of Product's subclasses. For a visual, here is my current 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
Everything currently works. However, I had to add this to the product model per this SOF question, although, I modified it to use update instead of new, to correct my specific issue.
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
If the build_actable method is not included, the create action works but update action does not. The error, without build_actable when I try to update a Product (subclass of Product) is...
Cannot build association actable. Are you trying to build a polymorphic one-to-one association?
Main Question
Although my current controller and build_actable method "works", every time I update a Product attribute, it updates updated_at three times...here is the log output...
Book Load (0.7ms) SELECT "books".* FROM "books" WHERE "books"."id" = $1 LIMIT $2 [["id", 13], ["LIMIT", 1]]
↳ app/controllers/products_controller.rb:45
Product Update (1.0ms) UPDATE "products" SET "name" = $1, "updated_at" = $2 WHERE "products"."id" = $3 [["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" = $1 WHERE "products"."id" = $2 [["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" = $1 WHERE "products"."id" = $2 [["updated_at", "2018-07-26 03:28:30.420007"], ["id", 13]]
↳ app/models/product.rb:22
(5.0ms) COMMIT
My controller should certainly be refactored...but why is it updating updated_at 3 times???
Note: I've tried calling build_actable directly instead of update in the controller...but it does the same thing. I have also removed timestamps from Product's subclasses. I feel like I'm missing something obvious....
