Class: ActiveModel::Type::Value
Overview
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.
Class Method Summary
-
.new(precision: nil, limit: nil, scale: nil) ⇒ Value
constructor
Initializes a type with three basic configuration settings: precision, limit, and scale.
Instance Attribute Summary
- #limit readonly
- #precision readonly
- #scale readonly
-
#binary? ⇒ Boolean
readonly
Internal use only
These predicates are not documented, as I need to look further into their use, and see if they can be removed entirely.
- #mutable? ⇒ Boolean readonly Internal use only
- #serialized? ⇒ Boolean readonly Internal use only
Instance Method Summary
- #==(other) (also: #eql?)
- #as_json
- #assert_valid_value(_)
-
#cast(value)
::ActiveModel::Type
casts a value from user input (e.g. from a setter). -
#changed?(old_value, new_value, _new_value_before_type_cast) ⇒ Boolean
Determines whether a value has changed for dirty checking.
-
#changed_in_place?(raw_old_value, new_value) ⇒ Boolean
Determines whether the mutable value has been modified since it was read.
-
#deserialize(value)
(also: #serialize)
Converts a value from database input to the appropriate ruby type.
-
#eql?(other)
Alias for #==.
- #hash
-
#serializable?(value) ⇒ Boolean
Returns true if this type can convert
value
to a type that is usable by the database. -
#serialize(value)
Casts a value from the ruby type to a type that the database knows how to understand.
-
#type
Returns the unique type name as a
::Symbol
. -
#cast_value(value)
private
Convenience method for types which do not need separate type casting behavior for user and database inputs.
- #force_equality?(_value) ⇒ Boolean Internal use only
- #map(value) Internal use only
-
#type_cast_for_schema(value)
Internal use only
::ActiveModel::Type
casts a value for schema dumping. - #value_constructed_by_mass_assignment?(_value) ⇒ Boolean Internal use only
SerializeCastValue
- Included
Constructor Details
.new(precision: nil, limit: nil, scale: nil) ⇒ Value
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.
Instance Attribute Details
#binary? ⇒ Boolean (readonly)
These predicates are not documented, as I need to look further into their use, and see if they can be removed entirely.
# File 'activemodel/lib/active_model/type/value.rb', line 77
def binary? # :nodoc: false end
#limit (readonly)
[ GitHub ]#mutable? ⇒ Boolean (readonly)
# File 'activemodel/lib/active_model/type/value.rb', line 140
def mutable? # :nodoc: false end
#precision (readonly)
[ GitHub ]#scale (readonly)
[ GitHub ]#serialized? ⇒ Boolean (readonly)
# File 'activemodel/lib/active_model/type/value.rb', line 136
def serialized? # :nodoc: false end
Instance Method Details
#==(other) Also known as: #eql?
[ GitHub ]#as_json
# File 'activemodel/lib/active_model/type/value.rb', line 144
def as_json(*) raise NoMethodError end
#assert_valid_value(_)
[ GitHub ]# File 'activemodel/lib/active_model/type/value.rb', line 133
def assert_valid_value(_) end
#cast(value)
::ActiveModel::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: #cast_value.
value
The raw input, as provided to the attribute setter.
# File 'activemodel/lib/active_model/type/value.rb', line 57
def cast(value) cast_value(value) unless value.nil? end
#cast_value(value) (private)
Convenience method for types which do not need separate type casting behavior for user and database inputs. Called by #cast for values except nil
.
# File 'activemodel/lib/active_model/type/value.rb', line 152
def cast_value(value) # :doc: value end
#changed?(old_value, new_value, _new_value_before_type_cast) ⇒ Boolean
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.
# 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) ⇒ Boolean
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:
-
pass
new_value
to #serialize and compare it toraw_old_value
or
-
pass
raw_old_value
to #deserialize and compare it tonew_value
raw_old_value
The original value, before being passed to #deserialize.
new_value
The current value, after type casting.
# File 'activemodel/lib/active_model/type/value.rb', line 105
def changed_in_place?(raw_old_value, new_value) false end
#deserialize(value) Also known as: #serialize
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 #cast.
value
The raw input, as provided from the database.
# File 'activemodel/lib/active_model/type/value.rb', line 43
def deserialize(value) cast(value) end
#eql?(other)
Alias for #==.
# File 'activemodel/lib/active_model/type/value.rb', line 127
alias eql? ==
#force_equality?(_value) ⇒ Boolean
# File 'activemodel/lib/active_model/type/value.rb', line 113
def force_equality?(_value) # :nodoc: false end
#hash
[ GitHub ]#map(value)
# File 'activemodel/lib/active_model/type/value.rb', line 117
def map(value, &) # :nodoc: value end
#serializable?(value) ⇒ Boolean
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.
# File 'activemodel/lib/active_model/type/value.rb', line 28
def serializable?(value) true end
#serialize(value)
# 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.
# File 'activemodel/lib/active_model/type/value.rb', line 34
def type end
#type_cast_for_schema(value)
::ActiveModel::Type
casts a value for schema dumping. This method is private, as we are hoping to remove it entirely.
# File 'activemodel/lib/active_model/type/value.rb', line 71
def type_cast_for_schema(value) # :nodoc: value.inspect end
#value_constructed_by_mass_assignment?(_value) ⇒ Boolean
# File 'activemodel/lib/active_model/type/value.rb', line 109
def value_constructed_by_mass_assignment?(_value) # :nodoc: false end