ActiveRecord::DefaultValue¶ ↑

initialize with default_values

sample¶ ↑

you can specify default values with hash:

class Book < ActiveRecord::Base
  default_values rating: 'r18', type: 'comic'
end

book = Book.new
book.rating # => "r18"
book.type # => "comic"
book.title # => nil

you can use instance values with lambda:

class Book < ActiveRecord::Base
  default_values type: 'comic', released_at: lambda { Time.now }
end

or with block:

class Book < ActiveRecord::Base
  default_values type: 'comic' do
    t = Time.now
    {released_at: t, edition_updated_at: t}
  end
end

book1 = Book.new
# wait 10 sec
book2 = Book.new
book1.release_at == book2.release_at # => false
book1.released_at == book1.edition_updated_at # => true