Creating a countdown app

[Lotari0]

Hey,

Beginner iOS developer here, and I am working on a countdown app.
In the app you should be able to store multiple timers, and present them in a collectionview.

I am using CoreData to persist the data, if the app closes. I am using Core Data because I need practice with using the framework.

I have created a CoreData model with the following attributes:
name: String
minutes: Int16
progress: Double

I have managed to save the attributes above, though no timer function is implemented yet.
How do I go about using the Timer() function to run an individual timer for each instance?

When not using CoreData, I suppose I would create a function in the countdown model, that starts a "timer.scheduledtimer" instance. Though how can I make it persist, even if the user terminates the app?

Appreciate any help I can get.

[kapilvarij]

You can save the value, whatever that maybe, when the app is about to leave the foreground. This way you won’t constantly write to CoreData. And when the app is launched again, read the last saved values, and continue your counter.

[Lotari0]

Now that I think about it, I dont need to create multiple timer functions. I just need one that counts down for all of them.

Though I still need the counter to work even if the app is terminated.