/dev/trouble
Eric Roller's Development Blog

An old trap that I keep to be falling into is this one:

> find . -name "Frameworks" -prune -or -name "Info.plist"
./Frameworks
./Info.plist

Notice how the Frameworks folder is also returned (since -prune defaults to true), but the intention was to exclude it! The solution is to add -print:

> find . -name "Frameworks" -prune -or -name "Info.plist" -print
./Info.plist

On Mac OS X 10.5 (Leopard) it appears to work fine, but when I quit my app, on a machine running 10.4 (Tiger), these messages appear in the Console:

2009-03-03 21:49:10.680 MyApp[6793] *** Illegal NSTableView data source
    (). Must implement numberOfRowsInTableView: and
    tableView:objectValueForTableColumn:row:
2009-03-03 21:49:23.139 MyApp[6793] *** -[NSCFString count]:
    selector not recognized [self = 0x1bc7f00]
2009-03-03 21:49:23.140 MyApp[6793] Exception raised during posting
    of notification.  Ignored.  exception: *** -[NSCFString count]:
    selector not recognized [self = 0x1bc7f00]

The interesting fact is that the MyApp class is the delegate of the NSTableView since it implements support for drag & drop. However, it is not designed to be the data source for the NSTableView. Instead, I use an NSArrayController through a binding in the NSTableView instance. This works fine until one quits.

What I suspect is happening (on Tiger) is that the NSArrayController is purged before the NSApp, which suddely remains as the only data source of the NSTableView, but without the access methods implemented.

The solution would be to implement dummy methods in the MyApp class for numberOfRowsInTableView: and tableView:objectValueForTableColumn:row: where one returns 0 and nil, respectively.