Include module in module


#1

Hi,

I have a situation like this:

module M

end

class C1

include M

end

class C2

include M

end

Now I want to add methods to C1 and C2 and whatever other class includes
M.

My first approach was:

module S

end

module M

include S

end

But this doesn’t work (meaning whatever methods I have in S are
undefined for instances of C1, C2).

So, how can I do that?

Thanks,

Ittay


#2

Ittay D. wrote:

class C2

module M
So, how can I do that?
I think I solved it:
module S
def self.included(other)
methods = instance_methods(false)
other.module_eval do
methods.each do |name|
name = name.to_sym
base.send :define_method, name, instance_method(name)
end
end
end
end

Ittay


#3

2008/12/8 Ittay D. removed_email_address@domain.invalid:

include M
end

Now I want to add methods to C1 and C2 and whatever other class includes M.

So, how can I do that?

There are at least these two possible approaches

  1. add methods to M
  2. create another module S and include it in all classes inheriting M
    2b. same as 2 but insert S only in the inheritance hierarchy of
    classes that directly include M

#!/bin/env ruby

module M
def m
“Mmmmh!”
end
end

class A
include M
end

class B
include M
end

approach 1

module M
def late
“late”
end
end

puts A.new.late, B.new.late

approach 2

module S
def even_later
“even_later”
end
end

ObjectSpace.each_object(Class) do |cl|
if cl.ancestors.include?(M) && !cl.ancestors.include?(S)
cl.class_eval { include S }
end
end

puts A.new.even_later, B.new.even_later

approach 2b

module S2
def x
“X”
end
end

ObjectSpace.each_object(Class) do |cl|
a = cl.ancestors
i = a.index(M)
if i && a[1…i].all? {|c| not Class === c}
cl.class_eval { include S2 }
end
end

puts A.new.x, B.new.x

Cheers

robert