[Rubycocoa-talk] Bindings working with notification from Ruby

[Jonathan P. <jp...@dc...>]

Hi,

After following the instructions on the FAQ [1], with a few fiddles, I 
have got Cocoa bindings on a Ruby object to work well. Please let me 
know what you think of these modifications - if they seem ok I'll try 
to update the Wiki FAQ page.

The main thing I wanted to support was notification from Ruby to Cocoa 
upon changing a value in Ruby.

I created the NSObject+RubyCocoaBindings.[mh] and ObjcID.rb files, 
adjusting the latter slightly. I've attached the modified ObjcID.rb 
file to this message. The result is a model object like this:

   class MyModel < OSX::NSObject
     kvc_accessor :name, :title
   end

The kvc_accessor meta-method takes care of wrapping the setter (key=) 
with the Cocoa bindings notifications. If the setter is already 
defined, it will be wrapped by the kvc_accessor:

   class MyModel < OSX::NSObject
     def foo=(value)
       @foo = value
       @foo_parsed = ... # do some parsing of foo
     end

     kvc_accessor :foo # wraps foo= with notification, also defines foo 
reader method
   end

Now, in other code, if you do 'model.foo = "Something"', any GUI 
objects bound will automatically update.

Thanks
Jonathan

[1] http://rubycocoa.sourceforge.net/w.en/FAQ.html