Ruby on Rails code explainers

ruby

class CreateCommentsWithCounterCache < ActiveRecord::Migration[7.1]
  def change
    create_table :posts do |t|
      t.string :title, null: false

How counter caches work in Rails

counter-cache migrations associations

Intermediate 6 steps

ruby

class ProductCatalog
  def featured_products
    Rails.cache.fetch("catalog/featured_products", expires_in: 12.hours) do
      Product.where(featured: true)

Caching patterns with Rails.cache.fetch

caching cache-keys expiry

Intermediate 5 steps

ruby

class RegistrationForm
  include ActiveModel::Model
  include ActiveModel::Attributes

How a Rails form object spans two models

form object validations transactions

Intermediate 7 steps