Is there a way to retrieve an NSPersistentStore knowing its URL?

Question

Is there a way to retrieve an NSPersistentStore knowing its URL?

Something like:

NSURL *url = @"aaa\bbbb\ccc\xyz.sqlite"

NSPersistenStore *ps =[NSPersistentStore persistentStoreFromURL: url];

[self DoSomethingWith: ps];

** Obviously the method 'persistentStoreFromURL' doesn't exist!

Extra infos:

I know this store is loaded in some Coordinator (I don't know which one) and I have to remove it from its coordinator before migrating its data to another store. I only know the URL for this store.

I am using several coordinators at the same time. I want to avoid to loop through them and then loop again through all theirs stores to check if the store.URL is equal to url. This is the reason I am asking if it is possible to get the store directly from its url and then get its coordinator wihout all the looping.

Answer 1

You can get the current store from the Persistent Store Coordinator with:

    NSURL *url = @"aaa\bbbb\ccc\xyz.sqlite"
    NSPersistentStoreCoordinator *yourPSC = self.psc // Create or obtain reference to your psc

    NSPersistentStore *ps = [yourPSC persistentStoreForURL:url];

    [self DoSomethingWith: ps];

If you do not know which of your psc contain the store at url, check yourPSC.persistentStores for contains a store with same url.

Like so:

   for (NSPersistentStore *store in yourPSC.persistentStores) {
       if ([store.URL isEqual:url]) {
           [yourPSC removePersistentStore:store error:nil];
       }
   }

Answer 2

You have to initialize a NSPersistentStoreusing the designated initializer

initWithPersistentStoreCoordinator:configurationName:URL:options:

as described in Apple documentation

You will also need a store coordinator for this.

If you want to remove a store from a coordinator, though, you will need to have access to the coordinator, otherwise there is no way of removing it. You can ask the NSPersistentStorefor its persistentStoreCoordinator though. Migration of stores is also supported, depending on what you actually want to achieve. Note that a migration to another store might cause UI problems.

If you only have an URL you will need to ask a coordinator if it is assigned to the store. I see no other way out of the box.