Question

I met strange difficulty developing one project. I dont have enough experience with classes so this is why I ask here. I have one class which is initialized with one parameter and I need other classes to call that class functions but I cant until that class is initialized so I asking how I could do that.

Here is some example what I talking about:

class AVR
    def initialize(device)
        @device = device
        @avr_conf = YAML::load(File.open("./devices/#{device}.yaml"))
    end

    def avr_conf
        return @avr_conf
    end
end

class IO
    def setMode(a,b)
        "#{AVR.avr_conf[a]} = #{b}"
    end
end

Answer 1

You either: need an instance, or to make avr_conf a class method (and initialize differently).

With an instance:

avr = AVR.new(a_device)
avr.avr_conf[a]

With a config singleton (roughly):

class AVR
  def self.class_initialize(device)
    @@avr_conf ... etc ...
  end

  def self.avr_conf
    return @@avr_conf
  end
end

Then class IO would need to use the updated version, however that’s appropriate.

If IO isn’t going to/can’t get an instance, the class/singleton-config might make more sense, although that approach always makes me a little nervous.