How to load the PersistentStores in a correct way? - swift

Question

I've been looking on Internet the entire weekend and today on how to handle correctly any error when the PersistentStores loads, without a success!
Actually, so many people are looking for the same solution but no one gets an answer. For example: https://www.hackingwithswift.com/forums/swift/core-data-error-checking/3794
Apple give us a fatalError in their template while telling us to not use it for a shipping application.
Here's also how you can have it, from many tutorials on Youtube, for example:
container.loadPersistentStores(completionHandler: { (storeDescription, error) in
if let error = error {
print("Core Data failed to load: \(error.localizedDescription)!")
}
print("Core Data succeed to load!")
})
As I'm not able to handle a potential error, because I still don't know how to do it, I'd love to just load it without handling any error ; but I can't just delete the if and the print and leave it blank. So, what should I put inside?

Answer 1

The question doesn't have a straightforward answer because what you do depends on what your app does and how you want it to respond in this situation. Every app's requirements are different, and you have not given any indication of yours.
If this error happens, your app has failed to load the persistent store. Whatever data might have been in that store is not available. New data cannot be saved to that store. What should you do? What can you do, in your app, to meet your requirements? What do you want your app to do if this persistent store is not available? What would you consider to be a reasonable response, in your specific app? That is what you do here.
There's no real recovery path; you can't simply make the error go away. You could try deleting the old persistent store and creating a new one. That would lose any previously saved data. Is that OK? It depends on you and your app. If you want to do that, look into the destroyPersistentStore(at:, type:, options:) function to remove it cleanly. Then try loading the store again, and a new one will be created.