1
0
Fork 0
mirror of https://github.com/rails/rails.git synced 2022-11-09 12:12:34 -05:00
rails--rails/activerecord/lib/active_record/attribute.rb
Sean Griffin a89f8a922d Move behavior of read_attribute to AttributeSet
Moved `Builder` to its own file, as it started looking very weird once I
added private methods to the `AttributeSet` class and the `Builder`
class started to grow.

Would like to refactor `fetch_value` to change to

```ruby
self[name].value(&block)
```

But that requires the attributes to know about their name, which they
currently do not.
2014-06-25 08:51:15 -06:00

102 lines
2 KiB
Ruby

module ActiveRecord
class Attribute # :nodoc:
class << self
def from_database(value, type)
FromDatabase.new(value, type)
end
def from_user(value, type)
FromUser.new(value, type)
end
def uninitialized(type)
Uninitialized.new(type)
end
end
attr_reader :value_before_type_cast, :type
# This method should not be called directly.
# Use #from_database or #from_user
def initialize(value_before_type_cast, type)
@value_before_type_cast = value_before_type_cast
@type = type
end
def value
# `defined?` is cheaper than `||=` when we get back falsy values
@value = type_cast(value_before_type_cast) unless defined?(@value)
@value
end
def value_for_database
type.type_cast_for_database(value)
end
def changed_from?(old_value)
type.changed?(old_value, value, value_before_type_cast)
end
def changed_in_place_from?(old_value)
type.changed_in_place?(old_value, value)
end
def type_cast
raise NotImplementedError
end
def initialized?
true
end
protected
def initialize_dup(other)
if defined?(@value) && @value.duplicable?
@value = @value.dup
end
end
class FromDatabase < Attribute # :nodoc:
def type_cast(value)
type.type_cast_from_database(value)
end
end
class FromUser < Attribute # :nodoc:
def type_cast(value)
type.type_cast_from_user(value)
end
end
class Null # :nodoc:
class << self
attr_reader :value, :value_before_type_cast, :value_for_database
def changed_from?(*)
false
end
alias changed_in_place_from? changed_from?
def initialized?
true
end
end
end
class Uninitialized < Attribute # :nodoc:
def initialize(type)
super(nil, type)
end
def value
nil
end
alias value_for_database value
def initialized?
false
end
end
end
end