If I have a class with an attr_accessor
, it defaults to creating an instance variable along with the corresponding getters and setters. But instead of creating an instance variable, is there a way to get it to create a class variable or a class instance variable instead?
Like this:
class TYourClass
class << self
attr_accessor :class_instance_variable
end
end
You can look at this as opening the metaclass of the class (of which the class itself is an instance) and adding an attribute to it.
attr_accessor
is a method of class Class
, it adds two methods to the class, one which reads the instance variable, and other that sets it. Here's a possible implementation:
class Class
def my_attr_accessor(name)
define_method name do
instance_variable_get "@#{name}"
end
define_method "#{name}=" do |new_val|
instance_variable_set "@#{name}", new_val
end
end
end
Completely untested class attribute accessor:
class Class
def class_attr_accessor(name)
define_method name do
class_variable_get "@@#{name}"
end
define_method "#{name}=" do |new_val|
class_variable_set "@@#{name}", new_val
end
end
end