Re: [Rubycocoa-talk] Optional method arguments in NSObject-subclass

[Johan L. <joh...@gm...>]

Okay so this SO-question helped a bit:
http://stackoverflow.com/questions/561185/optional-arguments-in-objective-c-2-0

I'm just gonna make two methods instead; one "filename" and another
"filenameWithLanguage" or something like that.

Sincerely,
Johan Lundström

joh...@gm...



2009/8/31 Johan Lundström <joh...@gm...>:
> What is the rules about optional method arguments in
> NSObject-subclasses? I recently upgraded from 0.13.1 to 1.0.0 and this
> problem appeared:
>
> class Subtitle < NSObject
>  def filename(add_language = false) # notice optional arg here!
>    # ...
>  end
> end
>
> When using "Build & Go" from Xcode it crashes immediately with this error:
>
> [...]/build/Debug/Undertext.app/Contents/Frameworks/RubyCocoa.framework/Resources/ruby/osx/objc/oc_import.rb:346:in
> `_ns_behavior_method_added': Cannot override Objective-C method
> 'filename' with Ruby method #filename, they should both have the same
> number of arguments. (expected arity 0, got -1) (RuntimeError)
>        from [...]/build/Debug/Undertext.app/Contents/Frameworks/RubyCocoa.framework/Resources/ruby/osx/objc/oc_import.rb:684:in
> `method_added'
>        from [...]/build/Debug/Undertext.app/Contents/Resources/Subtitle.rb:25
>        from [...]/build/Debug/Undertext.app/Contents/Resources/rb_main.rb:17:in
> `require'
>        from [...]/build/Debug/Undertext.app/Contents/Resources/rb_main.rb:17:in
> `rb_main_init'
>        from [...]/build/Debug/Undertext.app/Contents/Resources/rb_main.rb:16:in `each'
>        from [...]/build/Debug/Undertext.app/Contents/Resources/rb_main.rb:16:in
> `rb_main_init'
>        from [...]/build/Debug/Undertext.app/Contents/Resources/rb_main.rb:22
>
> When removing the argument or removing the default-value (ie. false) I
> get no error. My guess this is expected behaviour, but what is the
> exact rules and why?
>
> Sincerely,
> Johan Lundström
>
> joh...@gm...
>