Updating managed object core data
A managed object context is an in-memory scratchpad for working with your managed objects.
Most apps need just a single managed object context.
Start by viewing how the app creates the CSV strings for the // 1 let context = core Data Context var results: [Journal Entry] =  do catch let error as NSError // 2 let export File Path = NSTemporary Directory() "export.csv" let export File URL = URL(file URLWith Path: export File Path) File Manager.default.create File(at Path: export File Path, contents: Data(), attributes: nil) To open the exported CSV file, use Excel, Numbers or your favorite text editor to navigate to and open the file specified in the alert dialog.
Multiple managed object contexts make your apps harder to debug; it’s not something you’d use in every app, in every situation.
Calling , at the very least, generates a stack trace, which can be helpful when trying to fix the problem.
If your app has support for remote logging or crash reporting, you should log any relevant information that might be helpful for debugging before calling To support concurrent reads and writes, the persistent SQLite store in this sample app uses SHM (shared memory file) and WAL (write-ahead logging) files.
After each surf session, a surfer can use the app to create a new journal entry that records marine parameters, such as swell height or period, and rate the session from 1 to 5.
Dude, if you’re not fond of hanging ten and getting barreled, no worries, brah. On startup, the application lists all previous surf session journal entries.