Fixing NSManagedObject’s ObservableObject conformance

In working with SwiftUI you may have noticed that NSManagedObject is not a particularly correct implementation of ObservableObject. Your NSManagedObject does not publish changes when any of its @NSManaged properties are mutated.

There’s an easy fix for this:

open class ManagedObject: NSManagedObject {
    override public func willChangeValue(forKey key: String) {
        super.willChangeValue(forKey: key)

        objectWillChange.send()
    }
}

Simply tweak your model classes to inherit from ManagedObject, instead of NSManagedObject, et voilà  - your managed objects will behave as expected.

Explanation #

This essentially hooks into a core NSManagedObject method - willChangeValue(forKey:) and overrides it to also publish changes to the objectWillChange publisher when invoked.

 
13
Kudos
 
13
Kudos

Now read this

Removing List’s cell separators in SwiftUI

Currently, as of Xcode 11.1, Apple provides no way for developers to specify a cell separator style for SwiftUI’s List. Having run into this issue myself, I finally stumbled upon a workaround: UITableView.appearance().separatorStyle =... Continue →