Re: Logging NSData

[Wolfgang Lux]

Hi Andreas,

> Hi Richard,
>
> > > I am logging out NSDictionaries that sometimes contain NSData  
> > > instances as values. On MacOSX NSData::description is called to  
> > > determine a string that is used in the output. I don't want to  
> > > see tons of hex values for large NSData objects in the output and  
> > > therefore wrote the following category:
> > >
> > > @implementation NSData (SRDataExtension)
> > >
> > > - (NSString *)description
> > > {
> > >  return [NSString stringWithFormat:@"<data of length %d>", [self  
> > > length]];
> > > }
> > >
> > > @end
> > >
> > > This works great on MacOSX but not under GNUstep. It seems that  
> > > description is not called under GNUstep when a dictionary is  
> > > logged out with
> > >
> > >         NSLog(@"dic %@", dic);
> > >
> > > Any idea?
> >
> > GNUstep uses -descriptionWithLocale:
> >
> > Perhaps we should change that if it's no longer used in OSX?
>
> I have implemented
>
> - (NSString *)descriptionWithLocale:(id)locale
> {
>    return [NSString stringWithFormat:@"<data of length %d>", [self  
> length]];
> }
>
> no in my category, but this method isn't used either by NSLog(@"dic  
> %@", dic)!? :-(
>
> I checked core/base/Source/NSData.m but it has no implementation  
> for descriptionWithLocale: either!?

AFAIU, your problem appears to be the implementation of  
NSDictionary's -description method (or really - 
descriptionWithLocale:indent:). This method is implemented by  
converting the dictionary into a (old-style) property list and that  
code converts NSData instances without invoking their -description  
(or -descriptionWithLocale:) methods (for the obvious reason). So I  
guess, you'll have to override NSDictionary -description for now as  
well.

Wolfgang