Re: Need a native guide through "Cannot remove an observer" woods

FROM : Jack Repenning
DATE : Mon Apr 28 20:49:15 2008

On Apr 25, 2008, at 7:42 PM, Keary Suska wrote:

> on 4/25/08 6:49 PM, <email_removed> purportedly said:
>

>> - (void) setEntry:(SVNWCEntry *)value
>> {
>> [self willChangeValueForKey:@"entry"];
>>
>> [value retain];
>> [entry release];
>> entry = value;
>>
>> [self didChangeValueForKey:@"entry"];
>> }

>
> If you haven't turned off automatic KVO notifications, the above is 
> very
> wrong, and could be the source of your problem.



Thanks.  I think your hint worked. That is, I'm not sure what you were 
suggesting, but I took a guess, and it seems to have worked.  But I 
still don't quite grasp what's going on, so I'm begging for a touch of 
background?

What I did: remove the will/didChange stuff.

What happened: I no longer get the unable-to-remove-observer warning, 
nor the subsequent BAD_ACCESS crash.

Don't willChange and didChange merely notify and observers there may 
be that change is happening?  Why would redundant notification be a 
problem (other than perhaps performance, or possibly some obscure 
double-entry kind of response to the change, like adding up each value 
placed into an integer field)?


-==-
Jack Repenning
<email_removed>
Project Owner
SCPlugin
http://scplugin.tigris.org
"Subversion for the rest of OS X"