module ActiveModel::Attributes::ClassMethods

Public Instance Methods

attribute(name, type = Type::Value.new, **options) click to toggle source
# File lib/active_model/attributes.rb, line 18
def attribute(name, type = Type::Value.new, **options)
  name = name.to_s
  if type.is_a?(Symbol)
    type = ActiveModel::Type.lookup(type, **options.except(:default))
  end
  self.attribute_types = attribute_types.merge(name => type)
  define_default_attribute(name, options.fetch(:default, NO_DEFAULT_PROVIDED), type)
  define_attribute_method(name)
end
attribute_names() click to toggle source

Returns an array of attribute names as strings

class Person
  include ActiveModel::Attributes

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

Person.attribute_names
# => ["name", "age"]
# File lib/active_model/attributes.rb, line 39
def attribute_names
  attribute_types.keys
end

Private Instance Methods

define_default_attribute(name, value, type) click to toggle source
# File lib/active_model/attributes.rb, line 60
def define_default_attribute(name, value, type)
  self._default_attributes = _default_attributes.deep_dup
  if value == NO_DEFAULT_PROVIDED
    default_attribute = _default_attributes[name].with_type(type)
  else
    default_attribute = Attribute::UserProvidedDefault.new(
      name,
      value,
      type,
      _default_attributes.fetch(name.to_s) { nil },
    )
  end
  _default_attributes[name] = default_attribute
end
define_method_attribute=(name) click to toggle source
# File lib/active_model/attributes.rb, line 44
        def define_method_attribute=(name)
          ActiveModel::AttributeMethods::AttrNames.define_attribute_accessor_method(
            generated_attribute_methods, name, writer: true,
          ) do |temp_method_name, attr_name_expr|
            generated_attribute_methods.module_eval <<-RUBY, __FILE__, __LINE__ + 1
              def #{temp_method_name}(value)
                name = #{attr_name_expr}
                write_attribute(name, value)
              end
            RUBY
          end
        end