Support key-value observing via the attr_accessor family of methods

[jvoorhis@…]

As per the email thread at  http://lists.macosforge.org/pipermail/macruby-devel/2009-May/001705.html, extend attr_accessor and attr_writer to support key-value observing via setter methods.

Example:

class Notifier

attr_writer :value

end

Notifier#value= could be implemented in terms of Notifier#setValue so observers of Notifier receive notification when the value is changed.

[martinlagardette@…]

It is now supported with MacRuby. You can check with the nightlies.

However, please be aware that for notifications to work as expected, you will have to call #framework at least once:

# /tmp/kvn.rb

framework 'Foundation'

class Notifier
  attr_accessor :value
end
class Observer
  def observeValueForKeyPath(path, ofObject:object, change:change, context:context) puts change end
end

n = Notifier.new
n.addObserver(Observer.new, forKeyPath:'value', options:0, context:nil)
n.value = 42
n.setValue 42

$> macruby /tmp/kvn.rb 
{"kind"=>1}
{"kind"=>1}
$>

[lsansonetti@…]

It was fixed in r r3915.