Re: [Rubycocoa-talk] key-value observing

[Patrick G. <pge...@wa...>]

> It seems as if RubyCocoa's key-value observing works differently in
> some ways than Objective-C's would. Is this intentional? An incomplete
> implementation? The real question: is it stable behavior an app can
> depend upon?


Checking the source of kvc_accessor from oc_import.rb : declaring an  
accessor with kvc_accessor will call KVO methods in the setter.

setValue_forKey calls KVO methods + accessor, which again calls KVO  
methods, thus the 2 notifications. I don't know if that's correct.


     def kvc_accessor(*args)
       kvc_reader(*args)
       kvc_writer(*args)
     end

     def kvc_writer(*args)
       args.flatten.each do |key|
         setter = key.to_s + '='
         attr_writer(key) unless method_defined?(setter)
         alias_method kvc_internal_setter(key), setter
         self.class_eval <<-EOE_KVC_WRITER,__FILE__,__LINE__+1
           def #{kvc_setter_wrapper(key)}(value)
             willChangeValueForKey('#{key.to_s}')
             send('#{kvc_internal_setter(key)}', value)
             didChangeValueForKey('#{key.to_s}')
           end
         EOE_KVC_WRITER
         alias_method setter, kvc_setter_wrapper(key)
       end
     end