Dynamically hiding columns in a NSTableView

NSTableColumn *aColumn = [[NSTableColumn alloc] initWithIdentifier:attr];
[aColumn setWidth:DEFAULTCOLWIDTH];
[aColumn setMinWidth:MINCOLWIDTH];
[[aColumn headerCell] setStringValue:columnLabel];

[aColumn bind:@"value"
     toObject:arrayController
  withKeyPath:keyPath
  options:nil];

[tableView addTableColumn:aColumn];
[aColumn release];