[MacRuby-devel] forwardingTargetForSelector vs. MacRuby 0.4

[Laurent Sansonetti]

Hi Clay,

(Sorry for the late reply.)

I reproduce the same bug with trunk. I suspect a problem in the  
dispatcher. We should file this in as a macruby spec.

Did you try using the "old" methodSignatureForSelector: and - 
forwardInvocation: technique? This could work in the meantime the bug  
is fixed I think. It's what NSProxy uses I think and it works well  
with 0.4 and trunk.

Laurent

On Aug 15, 2009, at 11:13 AM, Clay Bridges wrote:

> Hi all,
>
> I'm using a forwardingTargetForSelector: to create a wrapper class in
> ObjC. It seems to work in ObjC, but when I try to use it in MacRuby
> 0.4, I get an error. As usual, it's likely I'm doing something quite
> foolish.
>
> Since it's kind of a complicated setup, rather than trying to describe
> code via email, I've created a minimal-ish project in github
> containing ObjC and MacRuby code to illustrate the problem. (I say
> minimal-ish, since I'm using XCode). It's here:
>
> http://github.com/diffengr/macruby_forwarding_invocation_example
>
> That contains an XCode project and a rakefile. It has the ObjC classes
> Candy and CandyWrapper, and they both have the NSString* property
> flavor. CandyWrapper declares that property @dynamic, and forwards it
> to Candy.
>
> Here's the code that works in ObjC.
>
>   Candy* rootBeerCandy = [[Candy alloc] init];
>   rootBeerCandy.flavor = @"Root Beer";
>
>   CandyWrapper* rootBeerWrapper = [[CandyWrapper alloc]
> initWithCandy:rootBeerCandy];
>   NSLog(@"Candy#flavor \"%@\", Wrapper#flavor \"%@\"",  
> rootBeerCandy.flavor,
>           rootBeerWrapper.flavor);
>
> If you load and run the xcode project in this directory, you'll get  
> this output:
>
>   NSLog[...] <CandyWrapper: 0x104fb0> forwarding flavor to <Candy:  
> 0x103380>
>   NSLog[...] Candy#flavor "Root Beer", Wrapper#flavor "Root Beer"
>
> Here's that (I think) same code instantiated in MacRuby, from  
> candy_test.rb:
>
>   rootBeerCandy = Candy.alloc.init
>   rootBeerCandy.flavor = 'Root Beer'
>
>   rootBeerWrapper = CandyWrapper.alloc.initWithCandy rootBeerCandy
>   puts "Candy#flavor #{rootBeerCandy.flavor}, Wrapper#flavor
> #{rootBeerWrapper.flavor}"
>
> You can run this with "macrake test" in the project directory, and it
> will give (among other things):
>
>   candy_test.rb:7:in `<main>': undefined method `flavor' for
> #<CandyWrapper:0x8000aa2a0> (NoMethodError)
>   rake aborted!
>
> So, what am I doing wrong?
>
> Thanks,
>
> Clay Bridges
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