[RUBY] Implement category function using ancestory

Introduction

When I went to a certain programming school and created a flea market app as a team, I implemented a multi-layered structure of categories, so I will introduce it! !!

Completion drawing

Then I would like to introduce it.

1. Creating a model

First, I want to link products and categories, so I will create models for "category" and "item".

$ rails g model category 

$ rails g model item 

2. Introduction of ance story

Introduce ancestory to Gemfile.

gem 'ancestry'

Execute the following command in the terminal

$ bundle install

$ rails g migration add_ancestry_to_category ancestry:string:index

$ rails db:migrate

3. Association

By using ancestory, the many-to-many relationship becomes a one-to-many relationship and the DB design becomes simple.

Describe has_ancestory in category.rb

category.rb

class Category < ApplicationRecord
　has_many :items
　has_ancestry　　
end

item.rb

class Item < ApplicationRecord
　belongs_to :category
end

3. Introduce data

We will introduce category records into seeds.rb.

seeds.rb

lady = Category.create(name: "Women")
lady_1 = lady.children.create(name: "tops")
lady_1.children.create([{name: "T-shirt/Cut and sew(Short sleeves/Sleeveless)"},{name: "T-shirt/Cut and sew(Seven minutes/Long sleeves)"},{name: "shirt/blouse(Short sleeves/Sleeveless)"},{name: "shirt/blouse(Seven minutes/Long sleeves)"},{name: "ポロshirt"},{name: "camisole"},{name: "Tank top"},{name: "Halter neck"},{name: "knit/sweater"},{name: "Tunic"},{name: "cardigan/Bolero"},{name: "ensemble"},{name: "Best/Gillet"},{name: "Parker"},{name: "trainer/sweat"},{name: "Bare top/Tube top"},{name: "Jersey"},{name: "Other"}])

If you include ancestry, you can treat it as a child element of the immediately preceding variable by writing .children.

The parent category, Ladies, is registered with the following description.

seeds.rb

lady = Category.create(name: "Women")

Next, the child category Tops is registered with the following description.

seeds.rb

lady_1 = lady.children.create(name: "tops")

Then, the grandchild category group is registered with the following description.

seeds.rb

lady_1.children.create([{name: "T-shirt/Cut and sew(Short sleeves/Sleeveless)"},{name: "T-shirt/Cut and sew(Seven minutes/Long sleeves)"},{name: "shirt/blouse(Short sleeves/Sleeveless)"},{name: "shirt/blouse(Seven minutes/Long sleeves)"},{name: "ポロshirt"},{name: "camisole"},{name: "Tank top"},{name: "Halter neck"},{name: "knit/sweater"},{name: "Tunic"},{name: "cardigan/Bolero"},{name: "ensemble"},{name: "Best/Gillet"},{name: "Parker"},{name: "trainer/sweat"},{name: "Bare top/Tube top"},{name: "Jersey"},{name: "Other"}])

After describing the record in seeds.rb, execute the following command in the terminal to reflect it in the DB.

$ rails db:seed

It is registered in DB like this.

Thank you for watching till the end! !!

I hope you found this article helpful: pray_tone2: