Question

What I want to achieve is something like below, i.e. calling a base class method from extended modules method:

class BaseClass
  def behavior
    puts 'base class behavior'
  end
end

module ChildModule
  def behavior
   super.behavior
   puts 'child module behavior'
  end
end

o = BaseClass.new
o.extend ChildModule
o.behavior

and it outputs as follows (with ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux])

base class behavior
t.rb:9:in `behavior': undefined method `behavior' for nil:NilClass (NoMethodError)
       from t.rb:16:in `<main>'

My guess is that I can not use super, as super does not exist in the module. But it prints out that line from the super method, is that strange?

How do I achieve it what I want above?

Answer by @davidrac is working, however being more curious, would like to know, how can I get a handle to base class instance? Say for instance I added the following method to BaseClass

def behavior2
  puts 'base class behavior2'
end

and overrides it in ChildModule. Now from ChildModule behavior can I make a call to behavior2 of BaseModule?

Answer 1

I think the correct syntax is:

module ChildModule
  def behavior
   super
   puts 'child module behavior'
  end
end