Instance Property


A more specific localized description of progress tracked by the receiver.


@property(copy) NSString *localizedAdditionalDescription;


If you don’t specify your own custom value for this property, NSProgress uses the value of the kind property to determine how to use the values of other properties, as well as values in the user info dictionary, to return an automatically-computed string. If it fails to do that, it returns an empty string.

The localizedAdditionalDescription is more specific than localizedDescription about the work the receiver is tracking at any particular moment. Depending on the kind of progress, the completed and total unit counts, and other parameters, example localized additional descriptions include:

  • 3 of 10 files

  • 123 KB of 789.1 MB

  • 3.3 MB of 103.92 GB – 2 minutes remaining

  • 1.61 GB of 3.22 GB (2 KB/sec) – 2 minutes remaining

  • 1 minute remaining (1 KB/sec)

By default, NSProgress is KVO-compliant for this property, sending notifications on the same thread that updates the property.

See Also

Reporting Progress


The total number of units of work tracked for the current progress.


The number of units of work for the current job that have already been completed.


A localized description of progress tracked by the receiver.