Core data ios10changes
- 1. Core Data Changes in iOS10 G. Abhisek
- 2. • Core Data Concepts. • Changes in Core Data. Contents:
- 3. • What is Core Data? • Core Data Stack: Managed Object Model Persistent Store Coordinator Managed Object Contexts Core Data Concepts
- 4. What is Core Data? • Its not a database. • Its a framework - Manages model layer objects in application. • Three types of files are generated when core data for an application is enabled : - .sqlite (Database file) - .sqlite-shm (Shared Memory) - .sqlite-wal (Write ahead log)
- 5. Core Data Stack • Managed Object Model - Data model of application. • Persistent Store Co-ordinator - The one which persists our data in the database. • Managed Object Context - Collection of model objects.
- 7. Core Data Changes • Persistent Containers • Query Generations • Concurrency Improvements
- 8. Persistent Containers • It creates a managed object model, and a managed object context. • Provides several properties and methods to interact with the Core Data stack. • Provides a description about the persistent store, its configuration, and whether it is a read-only persistent store.
- 9. • Initialise Persistent Store Container: let persistentContainer = NSPersistentContainer(name: "MyApplication") • Get the description of Persistent store: let persistentStoreDescription = NSPersistentStoreDescription(url: url) • Add Persistent Store to Persistent Store Coordinator
- 10. Faulting • When we fetch any entity from from Core Data database, we are returned back with not a fully initialised managed object, if its not required, rather it returns a kind of placeholder for the particular managed object’s instance. • When faults are inaccessible or faults are not fulfilled, we encounter an exception (crash in iOS8 & exception iOS9) • Resolve this issue by: Setting shouldDeleteInaccessibleFaults to proper value.
- 11. Query Generations • As of iOS 10 & 10.2, assigns a query generation to a managed object context. • It means it interacts with a snapshot of the data stored in the persistent store. • Any changes in the data base won’t affect the snapshot thereby avoiding a possible case of faults.
- 12. Concurrency Improvements • Earlier to iOS10, Persistent Stores locked themselves if different contexts accessed them from different threads, which results in performance issues, and slower Core Data procedures. • As of iOS 10, the persistent store is not allowed to lock itself away, and the query is directly moved to the SQLite database.
- 13. Thank You