Class: ActiveModel::Type::ImmutableString

Inherits:
Value show all
Defined in:
activemodel/lib/active_model/type/immutable_string.rb

Overview

Attribute type to represent immutable strings. It casts incoming values to frozen strings.

class Person
  include ActiveModel::Attributes

  attribute :name, :immutable_string
end

person = Person.new
person.name = 1

person.name # => "1"
person.name.frozen? # => true

Values are coerced to strings using their to_s method. Boolean values are treated differently, however: true will be cast to "t" and false will be cast to "f". These strings can be customized when declaring an attribute:

class Person
  include ActiveModel::Attributes

  attribute :active, :immutable_string, true: "aye", false: "nay"
end

person = Person.new
person.active = true

person.active # => "aye"

Direct Known Subclasses

String

Instance Attribute Summary

Attributes inherited from Value

#limit, #precision, #scale

Instance Method Summary collapse

Methods inherited from Value

#==, #assert_valid_value, #binary?, #cast, #changed?, #changed_in_place?, #deserialize, #force_equality?, #hash, #map, #serializable?, #type_cast_for_schema, #value_constructed_by_mass_assignment?

Constructor Details

#initialize(**args) ⇒ ImmutableString

Returns a new instance of ImmutableString.


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# File 'activemodel/lib/active_model/type/immutable_string.rb', line 36

def initialize(**args)
  @true  = -(args.delete(:true)&.to_s  || "t")
  @false = -(args.delete(:false)&.to_s || "f")
  super
end

Instance Method Details

#serialize(value) ⇒ Object


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# File 'activemodel/lib/active_model/type/immutable_string.rb', line 46

def serialize(value)
  case value
  when ::Numeric, ::Symbol, ActiveSupport::Duration then value.to_s
  when true then @true
  when false then @false
  else super
  end
end

#typeObject


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# File 'activemodel/lib/active_model/type/immutable_string.rb', line 42

def type
  :string
end