Realm in Swift (Berlin)

Berlin Swift Meetup

Transcript

1. Realm in Swift Build better apps faster Joe Anderson iOS @ Realm swift.berlin Berlin 11/24/2014
2. Why Realm was created Eliminate complexity Build & maintain apps faster
3. Why Now?
4. Core Data Full featured & mature 10+ years old ORM for SQLite Slow Complex and difficult to learn/debug Apple only
5. SQLite Faster than Core Data Optimized for iOS Cross Platform 14+ years old Bad User Experience Manual mapping and queries Lack of thread safety
6. What is Realm exactly? Fast, zero-copy, embedded database NoSQL Full ACID Transactions Simple Multithreading Model Universal Data - Cross Platform w/ C++ Core For Objective-C, Swift, Android
7. Model Simplicity class Person : RLMObject { dynamic var name = “” dynamic var saying = “” dynamic var type = “” dynamic var views = 0 }
8. Model Simplicity class Dog : RLMObject { dynamic var name = “” dynamic var age: int = 0 dynamic var owner: Person? } class Person : RLMObject { dynamic var name = “” dynamic var saying = “” dynamic var dogs = RLMArray(objectClassName: Dog.className()) }
9. Model Simplicity let realm = Realm.defaultRealm() let celebrity = Person() celebrity.name = “Sweet Brown” celebrity.saying = “Ain’t nobody got time for that” realm.beginWriteTransaction() realm.addObject(celebrity) realm.commitWriteTransaction()
10. Queries var allPeople = Person.allObjects()
11. Queries with Predicates var internetCelebs = Person.objectsWhere(“type = 'internet' AND name BEGINSWITH ’S’") let tonsOfViewsPred: NSPredicate = NSPredicate(format: “views > %@'', 10000000) var superStars = internetCelebs.objectsWithPredicate(tonsOfViewsPred)
12. How its possible Most are building on top of SQLite zero copy architecture bitpacking reduces memory usage up to 90% caching and vectorization makes it faster than native C universal data representation from multiple languages Photo by Natalie Lucier https://flic.kr/p/6vUu56
13. Common use cases Offline mode Caching (JSON/Object Mapping) Upload later Predictive Data Games Wearables Bluetooth Low Energy
14. JSON Mapper { name: “Sweet Brown”, saying: “Ain’t nobody got time for that”, dogs: [ { name: “Petey”, age: 1 }, { name: “Lucy”, age: 5 } ] …
15. JSON Mapper Works with any object not just JSON. Key-Value realm.beginWriteTransaction() Person.createInDefaultRealmWithObject(personFromApi) realm.commitWriteTransaction()
16. User Stories
17. Breezeworks “Run your entire service business from your phone” Uses Realm to embed & query large databases of tax rates & service codes 2m raised so far breezeworks.com j.mp/realm-breezeworks
18. Beanflow Full POS & inventory app (w/ offline mode) Uses Realm as network cache for all data “I don’t have any plans to go back to Core Data anytime soon. I really like Realm” sebastiandobrincu.com www.beanflow.com
19. Cloth Personal outfit diary Popular app with large user base Uses Realm for all data handling took over 2 year-old codebase and ported it to Realm in 1 day clothapp.com reallyseth.com
20. How to get started? Demo
21. Biggest mistakes people make when implementing Realm Creating foreign keys rather than thinking object based Ask whats the faulting model? People aren’t used to thinking of their objects in memory when it comes to databases
22. Migrations //v1 class Person : RLMObject { dynamic firstName = “” dynamic lastName = “” dynamic age: int = 0 } //v2 class Person : RLMObject { dynamic fullName = “” dynamic age: int = 0 }
23. Minimum Migration RLMRealm.setSchemaVersion(1, withMigrationBlock: { migration, oldSchemaVersion in // We haven’t migrated anything yet, so oldSchemaVersion == 0 if (oldSchemaVersion < 1) { // Nothing to do! // Realm will automatically detect new properties and removed properties // And will update the schema on disk automatically } })
24. Migrating Data Realm.setSchemaVersion(1, withMigrationBlock: { migration, oldSchemaVersion in if oldSchemaVersion < 1 { // The enumerateObjects:block: method iterates // over every 'Person' object stored in the Realm file migration.enumerateObjects(Person.className()) { oldObject, newObject in // combine name fields into a single field let firstName = oldObject[@"firstName"] as String let lastName = oldObject[@"lastName"] as String newObject[@"fullName"] = “\(firstName) \(lastName)” } } })
25. Work in progress Change notifications/Live results sets Delete Rules Open Source Core Enhanced Data Browser Sync
26. Questions? joe@realm.io @anderson760