core data in modern times
TRANSCRIPT
Core Data in Modern Times
Jorge D. Ortiz-Fuentes @jdortiz
#CoreDataMT
A Canonical Examples production
#CoreDataMT
Agenda★Background info
★Comparisons
• Realm
• Android Content Providers
★Concurrency in Core Data
★Threats to Core Data
★Protect yourself
Background Info
Core Data concepts★Data persistence
• Objects <-> Data
★ Relationships
• 1-1
• 1-M
• M-M
★ Store independence
Core Data
Persistent Store
Persistent Store
Persistent Store Coordinator Managed Object
Model
Managed Object Context
MO MO MO MO MO
Core Data Virtues★Visual model
★Seamless integration with Objective-C
★Relationships, deletion rules, Faulting & Uniquing
★Undo management and Change tracking
★KVC & KVO
★Filtering, sorting, grouping
★Versioning and migration
★Merge policies
FetchedResultsController Anatomy
★ iOS only
★Controller
• uses a fetch request
• coordinates getting data and caches them
• notifies of changes
Bindings
★OS X only
★Sync UI and Coredata
★Reduce the amount of code required
Comparisons are odious
Realm
Realm: Pros & Cons★Born mobile
★Models in code(PK)
★Built in encryption
★Multi-thread & Multi-process
★Good performance
★No delete rules
★No fine grained notifications (KVO)
★No null properties
★No sync solutions
Android Content Providers
Android Content★Content providers
• Abstract data sources
• Access to data via URI (REST style)
• It can be exported to other apps
• Thread safety via synchronized (or multi-instance)
★Content resolver to map authorities to providers
Concurrency in Core Data
Background Queue
Main Queue
Single process approach
★ Context
• Private
• MainQueue
★Nested contexts
• Save pushes changes to parent (no I/O)
• Parent saves in the background
child MOC
pStore
parent MOC
Good practices
★Avoid premature optimization
★Have a police for when to use concurrency
★Really follow 1 & 2
Also available now
★Batch updates (Brent Simmons’ problem)
★Asynchronous fetching
UIManagedDocument
★Uses the model in the bundle
★Async I/O
★Completion blocks after opening or saving
★Parent is in background and autosaves
★Also additional data
Threats to Core Data
Threats★Swift
• Introspection is still half baked (@NSManaged)
• Many features of Cocoa depend on the runtime
★ Lack of multi-process capabilities
★Apple generated doubts:
• Photos using
• Removed from Lister?
Protect yourself
– Robert C Martin (Uncle Bob)
“The database is a detail!”
Clean Architecture
View (VC) Presenter
Wireframe
Interactor Repository
Persistence
WSC
Thank you!
@jdortiz #CoreDataMT