Need a bit help on "module_function" method

Rails
1

The documentation is very straight forward and the mentioned example
also cleared all the lines except the one mentioned inside **.

Creates module functions for the named methods. These functions may be
called with the module as a receiver, and also become available as
instance methods to classes that mix in the module. Module functions are
copies of the original, and so may be changed independently. The
instance-method versions are made private. If used with no arguments,
subsequently defined methods become module functions.

module Mod
def one
“This is one”
end
module_function :one
end
class Cls
include Mod
def call_one
one
end
end
Mod.one #=> “This is one”
c = Cls.new
c.call_one #=> “This is one”
module Mod
def one
“This is the new one”
end
end
Mod.one #=> “This is one”
c.call_one #=> “This is the new one”

Please help me to understand what does mean by “If used with no
arguments, subsequently defined methods become module functions.”?

2

Please help me to understand what does mean by “If used with no
arguments, subsequently defined methods become module functions.”?

Okay got it now:-

module Party
module_function
def foo
“I am foo”
end
def bar
“I am bar”
end
end

Party.foo # => “I am foo”
Party.bar # => “I am bar”

3

On Aug 29, 2013, at 2:16 PM, Love U Ruby [email protected] wrote:

Please help me to understand what does mean by “If used with no
arguments, subsequently defined methods become module functions.”?

That means you can use it as a means of saying “All the methods defined
below are module functions”:

Module M

def foo
end

module_function

def bar
end

def baz
end

end

and so you can then call M.bar and M.baz, but not M.foo.

This is identical to:

Module M
def foo;end
def bar;end
def baz;end
module_function :bar, :baz
end

It is also identical to:

Module M
def foo;end
def self.bar; end
def self.baz; end
end