A helper library to work with CoreData.
The main class is CoreDataManager which provides a manager as a fascade to the underlying PersistentContainer which simplifies the correct usage of Core Data in an application.
The PersistentContainer is deriving from NSPersistentCloudKitContainer and thus CoreDataManager supports Core Data in the iCloud.
To include via SwiftPackageManager add the repository:
https://github.com/indieSoftware/INCoreData.git
How to use INCoreData: Usage
It's recommended to add -com.apple.CoreData.ConcurrencyDebug 1 as a runtime argument to the scheme to get Xcode errors when using Core Data wrongly and to get hints about potential undetected issues.
Use Xcode 14+ with Swift 5.7 or higher because that fixed some memory issues with Core Data and the async/await concurrency feature. As CoreDataManager_MemoryLeakTests shows the contexts and some referenced managed objects are not properly released.
However, even with Xcode 14 and Swift 5.7 be aware that tests might become flaky, that means they might sometimes pass and sometimes fail because a context or object is not released in time. For the objects to get released it's necessary to yield the main queue to give the system the chance to clean up those release pools. For that the lib's project uses a XCTestCase.yieldProcess() method which just sleeps for one nanosecond.
Just keep that in mind for own app tests when using Core Data.
Good resources for the general usage of CoreData:
- https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CoreData/index.html
- https://developer.apple.com/documentation/coredata
- https://developer.apple.com/documentation/coredata/mirroring_a_core_data_store_with_cloudkit/creating_a_core_data_model_for_cloudkit
- https://www.advancedswift.com/core-data-background-fetch-save-create
- https://cocoacasts.com/building-the-perfect-core-data-stack-with-nspersistentcontainer/