Realm iOS

Talk given at CocoaHeads Strasbourg

Transcript

1. Fadoua Kawni @eenwak CocoaHeads Strasbourg 16 march 2017
2. July 2014 Introduced in
3. Alexander S9gsen Bjarne Chris9ansen
4. Faster, simpler and mobile oriented.
5. iOS android cross-pla@orm
6. Source: Realm (15 septembre 2014) queries per seconds Counts Get counts of records matching a query on a databse of 200k records (higher is be;er) SQLite libraries Realm SQLite FMDB Core Data Couchbase Lite YapDatabase 0.066 0.069 1 13.6 13.6 30.9 40 30 20 10 0
7. Source: Realm (15 septembre 2014) queries per seconds Queries Iterate over all records matching a query (higher is be9er) SQLite libraries Realm SQLite FMDB Core Data Couchbase Lite YapDatabase 0.06 0.07 2 13 14 31 40 30 20 10 0
8. Source: Realm (15 septembre 2014) records inserted per seconds Inserts Insert 200K records, in a single transac4on (higher is be8er) SQLite libraries SQLite Realm FMDB Core Data YapDatabase Couchbase Lite 1.7K 5.1K 18K 47K 94K 178K 180K 135K 90K 45K 0K
9. Let’s begin
10. InstallaCon Carthage CocoaPods Framework
11. Represent stores on-disk or in-memory. Can be inspected with Realm Browser. Realms let realm = Realm()
12. Models
13. Subclass Object class Dog: Object { dynamic var name = "" dynamic var owner: Person? } …and that’s it.
14. Bool, Int, Double, Float, String, Date, and Data. Supported Types
15. RelaConships To-One To-Many Inverse
16. RelaConships To-One To-Many Inverse class Dog: Object { // to-one relationships must be optional dynamic var owner: Person? }
17. RelaConships To-One To-Many Inverse class Person: Object { // ... let dogs = List<Dog>() }
18. RelaConships To-One To-Many Inverse class Dog: Object { dynamic var name = "" dynamic var age = 0 let owners = LinkingObjects(fromType: Person.self, property: "dogs") }
19. Misc Objects are auto-updaCng Primary keys Indexed properCes
20. OperaCons
21. All changes to an Object must be done within a write transacCon.
22. Create / Add var myDog = Dog() myDog.name = "Rex" myDog.age = 10 // Add to realm try! realm.write { realm.add(author) } // Create using dictionary let myOtherDog = Dog(value: ["name" : "Pluto", "age": 3])
23. Update // … try! realm.write { realm.add(cheeseBook, update: true) } // … try! realm.write { realm.create(Book.self, value: ["id": 1, "price": 9000.0], update: true) }
24. Delete // … try! realm.write { realm.delete(cheeseBook) } // … try! realm.write { realm.deleteAll() }
25. Queries
26. Filter var whiteDogs = realm.objects(Dog.self) .filter("color = 'white'") using predicates let predicate = NSPredicate(format: "color = %@“, "white") whiteDogs = realm.objects(Dog.self).filter(predicate)
27. Sort let sortedDogs = realm.objects(Dog.self) .sorted(byKeyPath: "name") let dogOwners = realm.objects(Person.self) let ownersByDogAge = dogOwners.sorted(byKeyPath: "dog.age")
28. Chain let chainedDogs = realm.objects(Dog.self) .filter("color = ‘white'") .filter("age > 5") .sorted(byKeyPath: "name")
29. Queries are lazy and results are auto-updaCng.
30. CoreData vs Realm Queries in
31. func readPagesCount() -> Int { let predicate = NSPredicate(format: "statusValue == %d", BookStatus.finished.rawValue) return realm.objects(Book).filter(predicate).sum("pages") } func readPagesCount() -> Int { let predicate = NSPredicate(format: "statusValue == %d", BookStatus.FINISHED.rawValue) let expressionDesc = NSExpressionDescription() expressionDesc.name = "sumOfPages" expressionDesc.expression = NSExpression(forFunction: "sum:", arguments:[NSExpression(forKeyPath: "pages")]) expressionDesc.expressionResultType = .StringAttributeType var totalPages: Float = 0 let fetchRequest = NSFetchRequest(entityName: entityName) fetchRequest.propertiesToFetch = [expressionDesc] fetchRequest.resultType = .DictionaryResultType fetchRequest.predicate = predicate do { var results = try coreDataController.managedObjectContext?.executeFetchRequest(fetchRequest) if let dict = results![0] as? [String: String] { totalPages = Float(dict["sumOfPages"]!)! } } catch { fatalError("Failed to fetch data: \(error)") } return Int(totalPages) }
32. NoCficaCons
33. It is possible to be noCfied whenever a Realm, a collecCon or an Object is updated.
34. Realm // Observe Realm Notifications let token = realm.addNotificationBlock { (notification, realm) in viewController.updateUI() } // later token.stop()
35. CollecCon let results = realm.objects(Person.self).filter("age > 5") let token = results.addNotificationBlock { changes in switch changes { case .initial: // … case .update(_, let deletions, let insertions, let modifications): // … case .error(let error): // … } }
36. let token = stepCounter.addNotificationBlock { change in switch change { case .change(let properties): // … case .error(let error): // … case .deleted: // … } } Object
37. MigraCons
38. Realm supports migraCons out of the box.
39. Let’s migrate the Person model. class Person: Object { dynamic var firstName = "" dynamic var lastName = "" dynamic var age = 0 } class Person: Object { dynamic var fullName = "" dynamic var age = 0 }
40. let config = Realm.Configuration( schemaVersion: 1, migrationBlock: { migration, oldSchemaVersion in if oldSchemaVersion < 1 {/* Updates go here */} }) Realm.Configuration.defaultConfiguration = config let realm = try! Realm() realm will detect the changes automa9cally Simple migraCon
41. migration.enumerateObjects(ofType: Person.className) { oldObject, newObject in let firstName = oldObject!["firstName"] as! String let lastName = oldObject!["lastName"] as! String newObject!["fullName"] = "\(firstName) \(lastName)" } Modifying values
42. migration.renameProperty(onType: Person.className, from: "yearsSinceBirth", to: "age") Renaming
43. Data Sync
44. Realm Mobile PlaXorm Realm Object Server Realm Mobile Database = +
45. let usernameCredentials = SyncCredentials.usernamePassword (username: "username", password: "password") let googleCredentials = SyncCredentials.google(token: "Google token") let facebookCredentials = SyncCredentials.facebook(token: "Facebook token") let cloudKitCredentials = SyncCredentials.cloudKit(token: "CloudKit token") AuthenCcaCon
46. // Create the configuration let syncServerURL = URL(string: "realm://server:9080/~/userRealm")! let config = Realm.Configuration(syncConfiguration: SyncConfiguration(user: user, realmURL: syncServerURL)) // Open the remote Realm let realm = try! Realm(configuration: config) // Any changes made to this Realm will be synced across all devices ConfiguraCon
47. Thanks!