Code Explainers

Code explainers tagged #validations

ruby 
class Survey < ApplicationRecord
  has_many :questions, dependent: :destroy
  has_many :respondents, dependent: :nullify
 

Nested survey forms in Rails

nested-attributes validations associations
Intermediate 9 steps
ruby 
class Post < ApplicationRecord
  before_validation :generate_slug, on: :create
 
  validates :slug, presence: true, uniqueness: true

How a Rails model builds unique slugs

slugs callbacks validations
Intermediate 7 steps
ruby 
class Article < ApplicationRecord
  before_validation :generate_slug, on: :create
 
  validates :slug, presence: true, uniqueness: true,

How URL slugs work in Rails

callbacks validations slugs
Intermediate 7 steps
ruby 
class Employee < ApplicationRecord
  validates :name, presence: true
  validates :salary, numericality: { greater_than: 0 }
 

How STI models share behavior in Rails

single-table-inheritance inheritance method-overriding
Intermediate 8 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