I want to invoke method a from method of module B. How can I do it? I don't want to specify A::a every time.
module A
def self.a
"a"
end
end
module B
extend A
def self.b
a
end
end
p B::b # => undefined local variable or method `a' for B:Module
When using extend or include, Ruby will only mixin the instance methods. Extend will mix them in as class methods, but it won't mix in the class methods. Therefore, an easy solution to your query:
module A
def a ## Change to instance
"a"
end
end
module B
extend A
def self.b
a
end
end
p B::b #=> "a"
p B.b #=> "a"
I found here a method to solve it but it doesn't look good to me:
module A
module ClassMethods
def a
puts "a"
end
end
extend ClassMethods
def self.included( other )
other.extend( ClassMethods )
end
end
module B
include A
def self.b
a
end
end
p B::b # => "a"
You could try this "weird" code:
module A
def self.a
"a"
end
end
module B
extend A
def self.method_missing(name, *args)
if name =~ /a/
A::a *args
else
raise "MethodMissed: #{name}"
end
end
def self.b
a
end
end
p B::b
ais a class method onAif you haddef aand notdef self.ait would work as expected, otherwise useincludeinstead ofextendA::ato be a class method?extendsmechanism as in quandary's answer.A::ashould be module method. sorry