Core data database cleanup

CoreDataDatabaseCleanup.m

/*
For example, you use Core Data sqlite.
It is necessary, because sqlite database stores data in single file.
Whole database is single file.

Now you have two options.
1. Delete all data from all tables
2. Delete database sqlite file

Second option is clean but complex.
You should assure every piece of app that database sqlite file doesn't exists.
*/

+ (NSArray *)databaseFilenamesArray:(NSArray *<NSPersistentStore *>)stores {
    return [stores valueForKey:@"URL"];
}

+ (NSArray *)databaseEntitiesClassesForModel:(NSManagedObjectModel *)model {
    NSArray *result = @[];
    for (NSEntityDescription *description in model.entities) {
    	Class managedObjectClass = NSClassFromString([description managedObjectClassName]);
    	BOOL isManagedObject = [managedObjectClass isSubclassOfClass:[NSManagedObject class]];
    	if (isManagedObject) {
    		result = [result arrayByAddingObject:managedObjectClass];
    	}
    }
    return result;
}

+ (void)resetDatabaseModel:(NSManagedObjectModel *)model inContext:(NSManagedObjectContext *)context {
	[[self databaseEntitiesClassesForModel:model] enumerateObjectsUsingBlock:^(Class obj, NSUInteger idx, BOOL *stop) {
		// truncate all or delete all in iOS 9.
	    [obj performSelector:@selector(MR_truncateAllInContext:) withObject:localContext];
	}];
}

+ (void)removeDatabaseFilesForStores:(NSArray *<NSPersistentStore *>)stores {
    for (NSURL *url in [self databaseFilenamesArray:stores]) {
        if ([[NSFileManager defaultManager] fileExistsAtPath:url.path]) {
            result = result && [[NSFileManager defaultManager] removeItemAtURL:url error:&error];
        }
    }
}