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.
Determines whether a value has changed for dirty checking.
new_value will always be type-cast.
Types should not need to override this method.
Determines whether the mutable value has been modified since it was read.
false by default. If your type returns an object which
could be mutated, you should override this method. You will need to either:
new_valueto #serialize and compare it to
raw_old_valueto #deserialize and compare it to
raw_old_value The original value, before being passed to
new_value The current value, after type casting.
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.
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