Open Radar

 
Summary:
When using an NSLengthFormatter, it’s great that the default value will convert from meters to an automatically-selected unit, but there are cases when another unit would be preferred, and it’d be nice to have NSLengthFormatter take care of that conversion.

Steps to Reproduce:
1. Create an NSLengthFormatter.
2. Use -stringFromMeters with 402.336 meters, or a ¼ mile.

Expected Results:
The output is 0.25 miles.

Actual Results:
The output is 439.99 yards.

Notes:
Right now, this is possible by doing the conversion yourself:

double miles = meters * 0.00062137;

[self.lengthFormatter stringFromValue:miles
                                 unit:NSLengthFormatterUnitMile]; // 0.25 miles

But since NSLengthFormatter already has logic for converting between units built-in, it would be swell to do something like this:

self.lengthFormatter.preferredUnit = NSLengthFormatterUnitMile;