I want to call the same module method as a class method as well as an instance method in Ruby class. example
module Mod1
def method1
end
end
class A
end
I want to call method1 like
A.new.method1 or
A.method1.
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2 Answers
As @Karthik mentioned, you can have the class include and extend the module:
module Mod1
def method1
'hi'
end
end
class A
end
A.include Mod1
A.extend Mod1
A.new.method1 #=> 'hi'
A.method1 #=> 'hi'
A.extend Mod1 is nothing more than
A.singleton_class.include Mod1
When this is to be done it is not unusual to see the module written as follows.
module Mod1
def method1
'hi'
end
def self.included(klass)
klass.extend(self)
end
end
In this case the module need only be included by the class:
class A
end
A.include Mod1
A.new.method1 #=> 'hi'
A.method1 #=> 'hi'
Module::included is referred to as a callback or hook method. A.include Mod1 causes Mod1::included to be executed with klass equal to A and self equal to Mod1.
As an aside, there are several other callback methods that can be used to good effect. Arguably, the most important are Module::extended, Module::prepended and Class::inherited.
Comments
I cant imagine this is a good design.. but you can try to both include and extend the module into the class. include adds the methods as instance methods and `e
http://www.railstips.org/blog/archives/2009/05/15/include-vs-extend-in-ruby/
