Re: Leopard Properties and NSMutable Array

FROM : Bill Bumgarner
DATE : Sun Jan 06 02:53:59 2008

On Jan 5, 2008, at 5:41 PM, Jonathan wrote:
> self. content = [[NSMutableArray alloc] init];
> [self. content addObject:[NSString string];
>
> But I get the an error that tells me that I'm trying to mutate an 
> immutable collection.  Why is this, is the setter calling a -copy 
> method which returns an immutable copy? If so, why have this 
> behaviour?


That is because the synthesized method sends -copy to the mutable 
array, yielding an immutable array.

> Which argument to the @property directive would give the same as
>
> - (void)setContent:(NSArray *)newArray;
> {
>     if(content != newArray) {
>         [content release];
>         content = [[NSMutableArray alloc] initWithArray:newArray];
>     }
> }


Which, unfortunately, is the alternative.  There is an enhancement 
request already to offer a mutablecopy keyword.

b.bum