Ruby on Rails code explainers

ruby

class BulkImporter
  BATCH_SIZE = 500
 
  def initialize(records)

Batching bulk inserts in Rails

batching bulk-insert deduplication

Intermediate 5 steps

ruby

module Multitenant
  extend ActiveSupport::Concern
 
  included do

How a multitenant concern scopes Rails models

multitenancy default-scope concern

Advanced 8 steps

ruby

module Api
  module V1
    class BaseController < ActionController::API
      rescue_from StandardError, with: :render_internal_error

Centralized API error handling in Rails

error-handling rescue-from json-api

Intermediate 7 steps

ruby

class CartMergeService
  def initialize(guest_cart:, user_cart:)
    @guest_cart = guest_cart
    @user_cart = user_cart

Merging a guest cart into a user cart in Rails

service object transactions idempotency

Intermediate 7 steps

ruby

class Product < ApplicationRecord
  belongs_to :account
 
  after_save :record_audit_trail

Building an audit trail with Rails callbacks

callbacks audit-logging dirty-tracking

Intermediate 7 steps

ruby

class User < ApplicationRecord
  store_accessor :preferences,
    :theme,
    :timezone,

Storing user settings in a JSON column with Rails

store_accessor json-columns validations

Intermediate 7 steps

ruby

class Subscription < ApplicationRecord
  belongs_to :account
 
  enum :status, {

Modeling subscription lifecycle in Rails

enums scopes state-management

Intermediate 8 steps

ruby

class InactiveAccountCleanup
  BATCH_SIZE = 500
  INACTIVITY_THRESHOLD = 18.months

Batch-processing dormant users in Rails

batch-processing activerecord service-object

Intermediate 9 steps

ruby

class ArticleSerializer < ActiveModel::Serializer
  attributes :id, :title, :slug, :excerpt, :reading_time, :published_at, :url
 
  belongs_to :author, serializer: UserSerializer

Shaping API output with ActiveModel::Serializer in Rails

serialization json api computed attributes

Intermediate 9 steps

ruby

class SearchIndexReconciler
  DEBOUNCE_WINDOW = 5.seconds
 
  def self.schedule(record)

Debouncing search reindex jobs in Rails

debouncing background-jobs caching

Advanced 7 steps

ruby

module Api
  module V2
    class ArticlesController < Api::BaseController
      before_action :set_article, only: %i[show update destroy]

Building a versioned JSON API controller in Rails

rest-api serialization pagination

Intermediate 10 steps

ruby

class ArticlesController < ApplicationController
  before_action :set_article, only: %i[show edit update destroy publish]
 
  def edit

Policy-based authorization in a Rails controller

authorization policy-object before-action

Intermediate 9 steps

ruby

class ArticlesController < ApplicationController
  DEFAULT_LIMIT = 25
  MAX_LIMIT = 100

Cursor-based pagination in a Rails controller

pagination cursor query-building

Intermediate 7 steps

ruby

class Webhooks::StripeController < ApplicationController
  skip_before_action :verify_authenticity_token
  skip_before_action :authenticate_user!

How a Rails Stripe webhook controller works

webhooks signature verification event dispatch

Intermediate 7 steps

ruby

class ReportGenerator
  def initialize(account, period)
    @account = account
    @period = period

Memoized report metrics in Ruby in Rails

memoization query-composition service-object

Intermediate 7 steps

ruby

class PurgeStaleExportsJob < ApplicationJob
  queue_as :maintenance
 
  retry_on ActiveRecord::Deadlocked, wait: :polynomially_longer, attempts: 5

Purging stale exports with an Active Job in Rails

background-jobs batching error-handling

Intermediate 7 steps

ruby

class EmailValidator < ActiveModel::EachValidator
  EMAIL_FORMAT = /\A[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,}\z/i
 
  def validate_each(record, attribute, value)

Writing a custom email validator in Rails

validation regex custom validators

Intermediate 7 steps

ruby

class Api::V1::ArticlesController < Api::V1::BaseController
  def index
    articles = Article
      .published

Building a JSON:API endpoint in Rails

serialization eager-loading pagination

Intermediate 7 steps