Any way to pre populate core data?

Question

Hi all, ive been creating a list app and backing it with core data. I would like to have a default list of say 10 airport items so that the user doesnt have to start from scratch. Is there any way to do this? Any help is appreciated. Thanks in advance.

Answer 1

Yes there is in fact the CoreDataBooks example does this, you can download the code here: sample code

Basically just create your own sqlite database and add it to resources then when the application launches simply load it like this (copied from the sample code)

- (NSPersistentStoreCoordinator *)persistentStoreCoordinator {

if (persistentStoreCoordinator != nil) {
    return persistentStoreCoordinator;
}


NSString *storePath = [[self applicationDocumentsDirectory]      stringByAppendingPathComponent: @"CoreDataBooks.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:@"CoreDataBooks"      ofType:@"sqlite"];
 if (defaultStorePath) {
 [fileManager copyItemAtPath:defaultStorePath toPath:storePath error:NULL];
 }
}

NSURL *storeUrl = [NSURL fileURLWithPath:storePath];

 NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber   numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil]; 
  persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];

 NSError *error;
 if (![persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&error]) {
  // Update to handle the error appropriately.
  NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
 exit(-1);  // Fail
}    

return persistentStoreCoordinator;
}

Hope that helps.

-Oscar

Answer 2

For 10 items, you can just do this within applicationDidFinishLaunching: in your delegate. Define a method, say insertPredefinedObjects, that creates and populates the instances of the entity in charge of managing your airport items, and save your context. You may either read the attributes from a file or simply hardwire them in your code. Then, call this method inside applicationDidFinishLaunching:.

Answer 3

Here's the best way (and doesn't require SQL knowledge):
Create a quick Core Data iPhone app (Or even Mac app) using the same object model as your List app. Write a few lines of code to save the default managed objects you want to the store. Then, run that app in the simulator. Now, go to ~/Library/Application Support/iPhone Simulator/User/Applications. Find your application among the GUIDs, then just copy the sqlite store out into your List app's project folder.

Then, load that store like they do in the CoreDataBooks example.