NSNumberFormatter 10.0+ vs. 10.4+

FROM : Jamie Phelps
DATE : Sat Jan 26 23:14:48 2008

I'm working through Hillegass's Cocoa Programming for Mac OS X and ran 
into a problem with NSNumberFormatter that clearly can't be covered in 
the text and I haven't been able to find any helpful information from 
Google.

There is an NSTableView object in MyDocument.nib, and one column has 
an NSNumberFormatter applied set to display percentages. If I set the 
version to 10.0+ and enter a value without % into the cell, the app 
happily adds a % to make the entered value conform to the expected 
format. If I change the version to 10.4+ and enter a value without %, 
I get a sheet that says the value does not conform to the expected 
format.

So, I have two questions:

1) What is the difference between 10.0+ and 10.4+? Since I'm just 
starting out, I don't intend to support anything earlier than Leopard.

2) Is there a graceful way to handle these errors?

Thanks,
Jamie