On Jun 12, 2008, at 10:21 PM, Kyle Sluder wrote:
If you're implementing
the singleton pattern, for example, you would override -init
differently.
In most cases, I would strongly suggest *not* doing anything
differently if you are making a singleton. If you want something to
be a singleton, don't follow the "ensure there is only one instance of
this class" example. Instead, just implement a +sharedWhatever method
that returns a global, and does an +alloc/-init if necessary:
@implementation Foo
+ (id)sharedFoo {
static id sharedFoo = nil;
if (sharedFoo == nil) {
sharedFoo = [[self alloc] init];
}
return sharedFoo;
}
@end
No overrides of +allocWithZone:, -retain, -release, -autorelease or
anything of the sort. (Obviously if you're writing code that will
invoke +sharedFoo from multiple threads, you'll want to do appropriate
synchronization as well.)
This will be much easier to write reasonable unit tests for, since you
can still separately instantiate it (and therefore won't have to
"reset" anything after each). You will also be prepared for cases
where you need to promote something that starts as a singleton to a
non-singleton.
-- Chris
_______________________________________________
Cocoa-dev mailing list ([email protected])
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to [EMAIL PROTECTED]
