Ruby Language Modules A simple mixin with extend
Example
A mixin is just a module that can be added (mixed in) to a class. one way to do it is with the extend method. The extend method adds methods of the mixin as class methods.
module SomeMixin
def foo
puts "foo!"
end
end
class Bar
extend SomeMixin
def baz
puts "baz!"
end
end
b = Bar.new
b.baz # => "baz!"
b.foo # NoMethodError, as the method was NOT added to the instance
Bar.foo # => "foo!"
# works only on the class itself
