iOS Run function on value change Swift Core Data

[semaja2]

Hi Guys,

I am trying to learn Core Data using Swift, however I am lost at how to implement some more technical features.

Specifically I would like to have a function run before data is saved to the database, for example this could be used to verify or format the data before being saved.

On a normal class object I can use the below code

var lastAccuracyString: String {
        get {
            if (monitoring) {
                return NSString(format:"%.2f meters", lastAccuracy) as String
            } else {
                return "Unmonitored"
            }
        }
    }

What is the best way to extend the NSManagedObject class

 

[1458279]

Have you looked at KVO? http://nshipster.com/key-value-observing/
http://www.appcoda.com/understanding-key-value-observing-coding/