Multi-Store NSPersistentStoreCoordinator

gistfile1.m

- (NSManagedObjectModel *)managedObjectModel
{
    if (__managedObjectModel != nil)
    {
        return __managedObjectModel;
    }
    NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"SupersetModel" withExtension:@"mom"];
    __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
    return __managedObjectModel;
}

- (NSURL *)applicationDocumentsDirectory
{
    NSArray *searchPaths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
    NSString *documentPath = [searchPaths lastObject];
    
    return [NSURL fileURLWithPath:documentPath];
}

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (__persistentStoreCoordinator != nil)
    {
        return __persistentStoreCoordinator;
    }
    NSURL *dynURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"appname/dynStore.sqlite"];
    NSURL *persURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"appname/persStore.sqlite"];
    
    NSLog(@"dynURL %@", dynURL);
    NSLog(@"persURL %@", persURL);
    
    NSError *error1 = nil;
    NSError *error2 = nil;
    
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    
    
    // 1. Add "static", read-only store
    /* 
     * FAILS WITH: 
     * Error Domain=NSCocoaErrorDomain Code=134100 "The managed object model version used to open the persistent store is incompatible with the one that was used to create 
     * the persistent store." UserInfo=0x101374540 {metadata={
     * NSPersistenceFrameworkVersion = 407;
     * NSStoreModelVersionHashes =     {
     *   PersistentEnity1 = <2d9d5e0b d7f6f74d 918cb9af f0fe44a4 fae60105 8144ccd0 112d0729 cead71eb>;
     *   PersistentEnity2 = <e31f4b20 a3c302b6 7b2a74e1 2737e8cb d440ae9a 5bfb503b 32330cdd 17a98978>;
     *   PersistentEnity2 = <0ef429b0 41998c3a 496ab11a 26bde9ac 7d1a929f 9d7ea102 9ece131d b5a6890c>;
     * };
     * NSStoreModelVersionHashesVersion = 3;
     * NSStoreModelVersionIdentifiers =     (
     *  ""
     * );
     * NSStoreType = SQLite;
     * NSStoreUUID = "9FDD6F54-6734-43B9-A71B-8AC09F710F5D";
     * "_NSAutoVacuumLevel" = 2;
     * }, reason=The model used to open the store is incompatible with the one used to create the store}
     */

    [__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                               configuration:@"PersConfig"
                                                         persURL
                                                     options:@{
                             NSReadOnlyPersistentStoreOption: @(YES),
                     NSInferMappingModelAutomaticallyOption : @(YES)
     }
                                                       error:&error1];
    if (error1 != nil) {
        NSLog(@"1: %@", [error1 description]);
        return nil;
    }
    
    // 2. Add "dynamic", writable content
    [__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType
                                               configuration:@"DynConfig"
                                                         dynURL
                                                     options:@{
                NSMigratePersistentStoresAutomaticallyOption: @(YES),
                     NSInferMappingModelAutomaticallyOption : @(YES)
     }
                                                       error:&error1];
    
    
    if (error2 != nil) {
        NSLog(@"2: %@", [error2 description]);
        return nil;
    }
    
    return __persistentStoreCoordinator;
}

- (NSManagedObjectContext *)managedObjectContext
{
    if (__managedObjectContext != nil)
    {
        return __managedObjectContext;
    }
    
    NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
    if (coordinator != nil)
    {
        __managedObjectContext = [[NSManagedObjectContext alloc] init];
        [__managedObjectContext setPersistentStoreCoordinator:coordinator];
    }
    return __managedObjectContext;
}