My journey taming Core Data: An intro to the CoreStore library

Presented at the October 2017 Tokyo iOS Meetup.

Transcript

1. MY JOURNEY TAMING CORE DATA AN INTRO TO THE CORESTORE LIBRARY TOKYO IOS MEETUP JOHN ESTROPIA
2. ▸ @JohnEstropia ▸ @ ▸ OSS ABOUT ME http://github.com/JohnEstropia/CoreStore
3. WHAT I WON'T TEACH YOU ▸ Core Data
4. WHAT I'LL TALK ABOUT TODAY ▸ How I approached everyone's hate of Core Data ▸ Some CoreStore tricks to do common object persistence tasks
5. DEVS VERSUS CORE DATA
6. A LOT OF IOS DEVS HATE CORE DATA ▸ Not an understatement
7. A LOT OF IOS DEVS HATE CORE DATA ▸ Not an understatement
8. THE REASON? ▸ Speed? ▸ It's fast ▸ Database integrity? ▸ battle-tested for years ▸ Memory footprint? ▸ good lazying and caching mechanism ("faulting")
9. THE ACTUAL REASON ▸ Arguably the steepest learning curve among all iOS frameworks UIKit Core Data
10. CORE DATA:
11. HOW DEVS COPED
12. OTHERS: WROTE CORE DATA WRAPPERS ▸ Their approach: ▸ hide as much complexity as possible ▸ Syntax sugars ▸ Problems: ▸ Too much magic ▸ API users become too spoiled (pitfalls)
13. REALM: BUILT THEIR OWN SOLUTION ▸ Realm's primary marketing: ▸ "an alternative to SQLite and Core Data" ▸ Good API, fast database ▸ Issues: ▸ Some areas still need catching up (e.g. Migrations/ Versioning) ▸ Realm developers have proven they can catch up
14. ME: ALSO WROTE A CORE DATA WRAPPER ▸ CoreStore's approach: ▸ Make things easier, but just enough to keep users aware of pitfalls ▸ "Bad practices" should not be allowed to be written in the first place
15. safe but stagnant ❌ safe but open to expert options ✅
17. BUT WHY NOT JUST USE REALM? ▸ I started writing CoreStore in 2015 (Swift 1 beta) ▸ about 1 year before Realm was released
18. BUT WHY NOT JUST USE REALM? ▸ This is not a "Which is better?" debate ▸ If speed is a must, go with Realm ▸ I like Core Data's completeness as an Object Graph Manager ▸ Options are good for us!
19. I LIKE REALM TOO ▸ https://realm.io/addons/ https://github.com/eure/RealmIncrementalStore
21. BUT I DIGRESS...
22. CORESTORE TAMING CORE DATA
23. CORE DATA ISSUE 1: CROSS-THREAD CONSISTENCY ▸ CoreStore enforces transaction-based updates ▸ Main thread objects are read-only ▸ No way to save edits except inside transactions ▸ 3 kinds of Transactions ▸ Asynchronous ▸ Synchronous ▸ Unsafe
24. CORESTORE TRANSACTIONS
25. CORESTORE TRANSACTIONS
26. CORESTORE TRANSACTIONS
27. CORESTORE TRANSACTIONS
28. CORESTORE TRANSACTIONS
29. CORESTORE TRANSACTIONS
30. CORE DATA ISSUE 2: TYPO-SENSITIVE QUERIES ▸ CoreStore's syntax are all type-safe and concise
31. VANILLA CORE DATA FETCH
32. CORESTORE FETCH SWIFT 3 SWIFT 4
33. VANILLA CORE DATA QUERIES
34. CORESTORE QUERIES SWIFT 3 SWIFT 4
35. CORE DATA ISSUE 3: TEDIOUS MODELS ▸ Xcode model editor and NSManagedObject ▸ Need to sync *.xcdatamodeld (XML) files and NSManagedObject subclass source files ▸ CoreStore has a pure-swift way to create models
36. CORESTOREOBJECT
37. CORESTOREOBJECT
38. CORESTOREOBJECT: NO MORE XML FILES!
39. CORESTOREOBJECT: NO MORE XML FILES!
40. CORESTOREOBJECT: NO MORE XML FILES!
41. CORESTOREOBJECT: NO MORE XML FILES!
42. CORESTOREOBJECT: NO MORE XML FILES!
43. CORE DATA ISSUE 4: MODEL VERSIONING HAS INCREASING COST
44. CORE DATA ISSUE 4: MODEL VERSIONING HAS INCREASING COST
45. CORE DATA ISSUE 4: MODEL VERSIONING HAS INCREASING COST
46. CORE DATA ISSUE 4: MODEL VERSIONING HAS INCREASING COST ▸ CoreStore offers Progressive Migrations ▸ Just worry about the latest migration every time
47. CORESTORE PROGRESSIVE MIGRATIONS (*.XCDATAMODELD) LINEAR
48. CORESTORE PROGRESSIVE MIGRATIONS (*.XCDATAMODELD) CUSTOM
49. CORESTOREOBJECT VERSIONING EXAMPLE VERSION 1
50. CORESTOREOBJECT VERSIONING EXAMPLE VERSION 1 VERSION 2
51. CORESTOREOBJECT VERSIONING EXAMPLE
52. CORESTOREOBJECT VERSIONING EXAMPLE
53. WHAT IF I ACCIDENTALLY EDIT A CLASS? COPY THE LOGGED "VERSION LOCKS"
54. VERSIONLOCKS RUNTIME ASSERTION-CHECKED
55. OTHER CORESTORE FEATURES ▸ Type-safe observers for objects and lists ▸ Efficient importing utilities ▸ custom sources (e.g. JSON) ▸ uniquing ▸ Support for 3rd-party logging frameworks
56. SUPPORT ▸ Huge README documentation ▸ Full source code documentation ▸ Slack group: http://swift-corestore-slack.herokuapp.com/ ▸ Demo App
57. THANKS! @JohnEstropia