module ActiveModel::Attributes

Active Model Attributes¶ ↑

The Attributes module allows models to define attributes beyond simple Ruby readers and writers. Similar to Active Record attributes, which are typically inferred from the database schema, Active Model Attributes are aware of data types, can have default values, and can handle casting and serialization.

To use Attributes, include the module in your model class and define your attributes using the attribute macro. It accepts a name, a type, a default value, and any other options supported by the attribute type.

Examples¶ ↑

class Person
  include ActiveModel::Attributes

  attribute :name, :string
  attribute :active, :boolean, default: true
end

person = Person.new
person.name = "Volmer"

person.name # => "Volmer"
person.active # => true

class Person
  include ActiveModel::Attributes

  attribute :name, :string
  attribute :age, :integer
end

person = Person.new
person.attribute_names # => ["name", "age"]

# File activemodel/lib/active_model/attributes.rb, line 146
def attribute_names
  @attributes.keys
end

class Person
  include ActiveModel::Attributes

  attribute :name, :string
  attribute :age, :integer
end

person = Person.new
person.name = "Francesco"
person.age = 22

person.attributes # => { "name" => "Francesco", "age" => 22}

# File activemodel/lib/active_model/attributes.rb, line 131
def attributes
  @attributes.to_hash
end