Using Core Data created in one project as input to another project - ios

Question

I’ve found a couple of similar questions to this, but nothing that quite fits my needs. I’ve developed a simple digitizing app in Swift that presents an image and allows me to digitize specific points in the image using the simulator.
I use Core Data to save the data. One entity (“Coursemap”) has attributes for the image (Binary Data) and some meta data (Strings). The Coursemap entity has a one-to-many relationship with a “Points” entity. The Points entity defines attributes for the x/y coordinates for specific points in the image. The digitizer app is working well; I can digitize and save several images using Core Data. In the final version of my app I’ll probably need about 50-60 digitized images.
What I’d like to do is use the data from the output of my digitizer app as input to an iPad game I’m developing. So I basically want to copy the Core Data files created in my digitizer project over to my game project so my game app can use the digitized images. Is there a way to do this? Is Core Data the best way to handle this?
What I’ve tried so far: I name the two projects the same, but keep them in separate folders, e.g.:
~/digitizer/myApp and ~/games/myApp.
The digitizer core data files are created in the folder:
~/Library/Developer/CoreSimulator/Devices/…/Documents.
When I run the game app, it seems to expect the Core Data files to be in the same directory (which is why I named the two projects the same). When the game app tries to fetch data, I get the error, “The model used to open the store is incompatible with the one used to create the store”. I’ve double-checked the data models and they are identical.
Any ideas on this? Thanks.

Answer 1

I realized something similar:
- pick your prefilled sqlite file from the simulator folder
- copy it over to your other project
- during runtime, check on your other project if a sqlite structure exists and if it doesn't create it by copying the sqlite file from your bundle to the documents folder:
if(![[NSFileManager defaultManager]fileExistsAtPath:coreDataDatabase.path])
{
url = coreDataDatabase;
[[NSFileManager defaultManager] createDirectoryAtURL:url withIntermediateDirectories:YES attributes:nil error:NULL];
url = [url URLByAppendingPathComponent:#"StoreContent"];
[[NSFileManager defaultManager] createDirectoryAtURL:url withIntermediateDirectories:YES attributes:nil error:NULL];
url = [url URLByAppendingPathComponent:#"persistentStore"];
// copy the sqlite file to /Documents/<YourApp>/StoreContent/persistentStore
NSArray *stringParts = [kCoreDataPreloadedDatabase componentsSeparatedByString:#"."];
NSString *sqlitePath = [[NSBundle mainBundle]
pathForResource:[stringParts objectAtIndex:0] ofType:#"sqlite"];
NSError *anyError = nil;
BOOL success = [[NSFileManager defaultManager]
copyItemAtPath:sqlitePath toPath:[url path] error:&anyError];
if(!success)
{
Error(#"Unable to copy sqlite file: %#", anyError);
}
}