evil_subclass.rb

# RubyMotion doesn't seem to support using subclasses to override methods from Objective-C classes.
# Here's probably an awful way to achieve the effect of subclassing:

class AlanView
  def init
    @uiview = UIView.alloc.init
    self
  end

  def addSubview(view)
    fakeSuper = @uiview.addSubview(view)
    puts "I can extend functionality here"
    fakeSuper
  end

  def method_missing(method, *args, &block)
    @uiview.send(method, *args, &block)
  end

  def self.method_missing(method, *args, &block)
    UIView.send(method, *args, &block)
  end
end

# usage:
mySubview = UIView.alloc.init
myAlanView = AlanView.alloc.init
myAlanView.addSubview(mySubview) #=> "I can extend functionality here"
AlanView.layerClass #=> CALayer