[MacRuby-devel] forwardingTargetForSelector vs. MacRuby 0.4
Clay Bridges
diffengr at gmail.com
Sat Aug 15 11:13:42 PDT 2009
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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