Where is 'activity' defined in this RubyMotion code?

Question

In this code, 'activity' is used but never defined. Where is it first defined? I'm confused...

https://github.com/HipByte/RubyMotionSamples/blob/master/android/Conference/app/about_fragment.rb#L4

Answer 1

The AboutFragmentclass inherits from Android::App::Fragment, so the most likely answer is that activity is defined as an instance method on Android::App::Fragment.

A simplified version of how that might work is:

module Android   
  module App
    class Fragment
      def activity
        "Activity!"
      end
    end
  end
end

class AboutFragment < Android::App::Fragment
  def onCreateView
    puts activity # Will print "Activity!"
  end
end