On 22 Jan 2010, at 04:06, Graham Cox wrote: > I have text fields which use NSNumberFormatters that occasionally need to > show a mixed value. > > My preferred design is that when they contain a mixed value, they show '--'. > My problem is that I can't seem to get the formatters to return this string. > For example, the formatter has the 'nil symbol' and 'NaN symbol' set to this, > but calling [textField setObjectValue:nil] doesn't display it. If I try and > directly set the field's string using [textField setStringValue:@"--"] the > formatter converts this to 0. > > I've tried subclassing the formatter and directly attempting to detect nil or > [NSNull null] as the object value but it never works, because the object > passed is always an NSNumber with value 0 even if the field is set with a > string or nil. > > Any ideas how I can achieve what I want here? > I see the same behaviour when subclassing NSNumberFormatter. - (NSString *)stringForObjectValue:(id)anObject always receives an NSNumber.
If you subclass NSFormatter directly then you can probably gain the control you need and detect the underlying object type. http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/DataFormatting/Articles/CreatingACustomFormatter.html Regards Jonathan Mitchell Developer http://www.mugginsoft.com > --Graham > > > _______________________________________________ > > 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/jonathan%40mugginsoft.com > > This email sent to [email protected] _______________________________________________ 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]
