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class ActiveModel::Type::Value

Active Model Value Type

The base class for all attribute types. This class also serves as the default type for attributes that do not specify a type.

Inherits From

Attributes

[R] limit
[R] precision
[R] scale

Public class methods

new(precision: nil, limit: nil, scale: nil)

Initializes a type with three basic configuration settings: precision, limit, and scale. The Value base class does not define behavior for these settings. It uses them for equality comparison and hash key generation only.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 17
def initialize(precision: nil, limit: nil, scale: nil)
  super()
  @precision = precision
  @scale = scale
  @limit = limit
end

Public instance methods

==(other)

Also aliased as: eql?.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 121
def ==(other)
  self.class == other.class &&
    precision == other.precision &&
    scale == other.scale &&
    limit == other.limit
end

as_json(*)

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 144
def as_json(*)
  raise NoMethodError
end

assert_valid_value(_)

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 133
def assert_valid_value(_)
end

cast(value)

Type casts a value from user input (e.g. from a setter). This value may be a string from the form builder, or a ruby object passed to a setter. There is currently no way to differentiate between which source it came from.

The return value of this method will be returned from ActiveRecord::AttributeMethods::Read#read_attribute. See also: Value#cast_value.

value The raw input, as provided to the attribute setter.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 57
def cast(value)
  cast_value(value) unless value.nil?
end

changed?(old_value, new_value, _new_value_before_type_cast)

Determines whether a value has changed for dirty checking. old_value and new_value will always be type-cast. Types should not need to override this method.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 84
def changed?(old_value, new_value, _new_value_before_type_cast)
  old_value != new_value
end

changed_in_place?(raw_old_value, new_value)

Determines whether the mutable value has been modified since it was read. Returns false by default. If your type returns an object which could be mutated, you should override this method. You will need to either:

or

raw_old_value The original value, before being passed to deserialize.

new_value The current value, after type casting.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 105
def changed_in_place?(raw_old_value, new_value)
  false
end

deserialize(value)

Converts a value from database input to the appropriate ruby type. The return value of this method will be returned from ActiveRecord::AttributeMethods::Read#read_attribute. The default implementation just calls Value#cast.

value The raw input, as provided from the database.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 43
def deserialize(value)
  cast(value)
end

eql?(other)

Alias for: ==.

hash()

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 129
def hash
  [self.class, precision, scale, limit].hash
end

serializable?(value)

Returns true if this type can convert value to a type that is usable by the database. For example a boolean type can return true if the value parameter is a Ruby boolean, but may return false if the value parameter is some other object.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 28
def serializable?(value)
  true
end

serialize(value)

Casts a value from the ruby type to a type that the database knows how to understand. The returned value from this method should be a String, Numeric, Date, Time, Symbol, true, false, or nil.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 65
def serialize(value)
  value
end

type()

Returns the unique type name as a Symbol. Subclasses should override this method.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 34
def type
end

Private instance methods

cast_value(value)

Convenience method for types which do not need separate type casting behavior for user and database inputs. Called by Value#cast for values except nil.

Source code GitHub 
# File activemodel/lib/active_model/type/value.rb, line 152
def cast_value(value) # :doc:
  value
end

Definition files