Prepopulate Core Data in iOS 5 - objective-c

Question

There seem to be some modifications to the NSPersistentStoreCoordinator method is iOS 5.
I am trying to get a prepopulated database ... it doesn't seem to work, no crash but none of the data seems to exist... Any suggestions?
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (__persistentStoreCoordinator != nil)
{
return __persistentStoreCoordinator;
}
NSURL *storePath = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"DataModel.sqlite"];
/*
Set up the store.
For the sake of illustration, provide a pre-populated default store.
*/
NSFileManager *fileManager = [NSFileManager defaultManager];
// If the expected store doesn't exist, copy the default store.
if (![fileManager fileExistsAtPath:[storePath absoluteString]]) {
NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:#"DataModel" ofType:#"sqlite"];
if (defaultStorePath) {
[fileManager copyItemAtPath:defaultStorePath toPath:[storePath absoluteString] error:NULL];
}
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"DataModel.sqlite"];
NSError *error = nil;
__persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error])
{
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return __persistentStoreCoordinator;
}

Answer 1

The problem is in the applicationDocumentsDirectory method that gives wrong absolute string. It is not really wrong, but is not suited for NSFileManager class.
The solution is simple. You need to write another method which I called applicationDocumentsDirectory2.
So first, go to header file of your AppDelegate and declare method:
- (NSString *)applicationDocumentsDirectory2;
Now, go to the .m file, and define a method:
- (NSString *)applicationDocumentsDirectory2 {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
return basePath;
}
And finally, just change persistentStoreCoordinator method into:
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (__persistentStoreCoordinator != nil)
{
return __persistentStoreCoordinator;
}
NSError *error = nil;
NSString *storePath = [[self applicationDocumentsDirectory2] stringByAppendingPathComponent: #"DataModel.sqlite"];
/*
Set up the store.
For the sake of illustration, provide a pre-populated default store.
*/
NSFileManager *fileManager = [NSFileManager defaultManager];
// If the expected store doesn't exist, copy the default store.
if (![fileManager fileExistsAtPath:storePath]) {
NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:#"DataModel" ofType:#"sqlite"];
if (defaultStorePath) {
if(![fileManager copyItemAtPath:defaultStorePath toPath:storePath error:&error]) {
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
}
}
}
NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:#"DataModel.sqlite"];
__persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error])
{
NSLog(#"Unresolved error %#, %#", error, [error userInfo]);
abort();
}
return __persistentStoreCoordinator;
}
That's it! :)