[Rubycocoa-talk] Pointer arguments to Obj-C methods

[Knud H. M. <knu...@de...>]

Hi,

how does one call methods like -[NSFileManager  
fileExistsAtPath:isDirectory:] from Ruby, where the second parameter  
is a pointer (in this case to a BOOL)? The Obj-C use is like this:

BOOL isDir;
NSFileManager *fileManager = [NSFileManager defaultManager];
if ([fileManager fileExistsAtPath:@"/bla/blub" isDirectory:&isDir] &&  
isDir) {
     doSomething();
     // ...

My naive attempt at using this from Ruby:
isDirectory = FALSE
OSX::NSFileManager.defaultManager.fileExistsAtPath_isDirectory?(path,  
isDirectory)
if (isDirectory)
    doSomething
    ...
end

As expected, this doesn't work. I get:
KNTileViewerAppController#scanDirectory: OSX::OCDataConvException:  
Cannot convert the argument #1 as '^B' to Objective-C
	/System/Library/Frameworks/RubyCocoa.framework/Resources/ruby/osx/ 
objc/oc_wrapper.rb:50:in `ocm_send'
	/System/Library/Frameworks/RubyCocoa.framework/Resources/ruby/osx/ 
objc/oc_wrapper.rb:50:in `method_missing'

Any suggestions?

Cheers,
Knud
-------------------------------------------------
Knud Möller, MA
+353 - 91 - 495086
Smile Group: http://smile.deri.ie
Digital Enterprise Research Institute
   National University of Ireland, Galway
Institiúid Taighde na Fiontraíochta Digití
   Ollscoil na hÉireann, Gaillimh