From: timr <timrandg@...>
Date: 2009-08-26T07:45:05+09:00
Subject: Re: Calling method from another class

On Aug 24, 3:12 pm, Kostas Lps <loup...@gmail.com> wrote:
> Hi guys,
> i have 2 classes say class A and class B. How can the A object that i'll
> create to call a class B method????
> Say we have this code:
>
> class A
>   def printA
>     puts = "Class A method"
>   end
> end
>
> class B
>   def printB
>     puts "Class B method"
>   end
> end
>
> I want to make something like this:
> a = A.new
> a.printB
>
> I this possible someway??? I dont want to use modules.
>
> Thanx in advance
> Kostas L.
> --
> Posted viahttp://www.ruby-forum.com/.

Could you do this:

class A
  def putsFromA
    puts "hello from A"
  end
end

class B
  def initialize(anA)
    @anA = anA
  end
  def putsFromB
    puts "hello from B"
  end
  def getAMessageFromB
  @anA.send :putsFromA
  end
end

a = A.new
b = B.new(a)
b.getAMessageFromB
# >> hello from A

If you made class methods rather than instance methods you could get
even closer to the desired syntax:

class A
  def self.putsFromA
    puts "hello from A"
  end
end

class B
  def self.putsFromB
    puts "hello from B"
  end

  def self.getAMessageFromB
  A.send :putsFromA
  end

end

B.getAMessageFromB
# >> hello from A

So modules would be one way, using the send method with an symbol
representing the name of the method as an argument is another. I think
it is closer to what you were hopping for originally. It basically
making the B class a proxy for A, at least for one specified method
(it receives a method call and forwards it to the actual target
class).
Tim