Feedback: How I brought Kotlin into my Room (short)

Transcript

1. HOW I BROUGHT KOTLIN INTO MY ROOM FEEDBACK Robin Caroff @RobinCaroff robin.caroff@gmail.com
2. Previously in Android…
3. Google announced Android Architecture Components
4. and…
5. Kotlin support as an official Android language
6. Context
7. Android Known issues ‣ Lifecycle
8. Android Known issues ‣ Lifecycle
9. ‣ Activity —> God object ‣ Code highly framework dependent ‣ Dependencies hell Android Known issues ‣ Lifecycle
10. Power : Its community ‣ Libraries ‣ Blogs, conferences, etc. ‣ Tools ‣ Practices ‣ Architectures ‣ Activity —> God object ‣ Code highly framework dependent ‣ Dependencies hell Android Known issues ‣ Lifecycle
11. Librairies
12. Librairies Architecture and
13. Architecture Model View Presenter
14. What about the Architecture Components ?
15. Architecture Components View Model Live Data Lifecycles Room Paging Library
16. Architecture Components View Model Live Data Lifecycles Room Paging Library
17. Architecture Components View Model Live Data Lifecycles Room Paging Library
18. Architecture Components View Model Live Data Lifecycles Room Paging Library
19. Architecture Components View Model Live Data Lifecycles Room Paging Library
20. Let’s get started !
21. Let’s get started ! Requirements Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !)
22. Let’s get started ! Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !) Requirements
23. Let’s get started ! Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !) Requirements References
24. Let’s get started ! Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !) Requirements References Books Talks / Podcasts Code
25. Let’s get started ! Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !) Requirements References Books Talks / Podcasts Code
26. Let’s get started ! Kotlin —> Android Studio 3.0 (now in stable channel) Architecture Components —> Google Maven repository (1.0.0 now stable as well !) Requirements References Books Talks / Podcasts Code
27. References Code Look at the generated Java code !
28. References Code Look at the generated Java code !
29. References Code Look at the generated Java code ! weightsChart = this.chart_weights WeightsChart var3 = (WeightsChart)this._$_findCachedViewById(id.chart_weights); Intrinsics.checkExpressionValueIsNotNull(var3, "this.chart_weights"); this.weightsChart = var3;
30. References Code Look at the generated Java code ! public android.view.View _$_findCachedViewById(int var1) { if(this._$_findViewCache == null) { this._$_findViewCache = new HashMap(); } android.view.View var2 = (android.view.View)this._$_findViewCache.get(Integer.valueOf(var1)); if(var2 == null) { var2 = this.findViewById(var1); this._$_findViewCache.put(Integer.valueOf(var1), var2); } return var2; }
31. References Code Android Architecture Blueprints https://github.com/googlesamples/android- architecture
32. Room
33. Room ORM: Object Relational Mapping
34. Room ORM: Object Relational Mapping Uses annotations
35. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax
36. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters class DateConverter { @TypeConverter fun toDate(timestamp: Long?): Date? { return if (timestamp == null) null else Date(timestamp) } @TypeConverter fun toTimestamp(date: Date?): Long? { return date?.time } }
37. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters Offers conflict resolution strategies @Dao interface UserDao { @Query("select * from user") fun loadAllUsers(): Single<List<User>> @Insert(onConflict = REPLACE) fun insertUser(user: User) }
38. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters Even better in Kotlin @Entity @TypeConverters(DateConverter::class) class Weight { @ColumnInfo(name = "kilogramsValue") var kilogramsValue: Float = 0.0f @ColumnInfo(name = "date") @PrimaryKey(autoGenerate = false) var date: Date? = null } Offers conflict resolution strategies
39. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters @Dao interface UserDao { @Query("select * from user") fun loadAllUsers(): Single<List<User>> @Query("select * from user where id = :arg0") fun loadUserById(id: Int): Maybe<User> } Even better in Kotlin Offers conflict resolution strategies *ish
40. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters @Dao @TypeConverters(DateConverter::class) interface WeightDao { @Query("select * from weight") fun loadAllWeights(): Flowable<List<Weight>> @Query("select * from weight where date = :arg0") fun loadWeightByDate(date: Date): Maybe<Weight> } Even better in Kotlin Offers conflict resolution strategies Compatible with Live Data or RxJava *ish
41. Room ORM: Object Relational Mapping Uses annotations Uses SQL syntax You can provide type converters Offers conflict resolution strategies Compatible with Live Data or RxJava Threads, Benchmarks, etc. ? Even better in Kotlin *ish
42. Tests
43. Tests Mockito 1 Error Mockito cannot mock/spy following: - final classes - anonymous classes - -primitive type
44. Tests Mockito 2 Error Mockito cannot mock/spy following: - final classes
45. Tests Mockito 2 Error Mockito cannot mock/spy following: - final classes Solution : mock-maker-inline
46. Tests Room Test migrations
47. Tests Room Test migrations Test Database with in-memory database
48. Tests Room Test migrations Test Database with in-memory database
49. Tests Room Test migrations Test Database with in-memory database
50. Tests Room Test migrations Test Database with in-memory database Test RxJava flowable queries @get:Rule var instantTaskExecutorRule = InstantTaskExecutorRule() @Before fun initDb() { database = Room.inMemoryDatabaseBuilder(InstrumentationRegistry.getContext(), UsersDatabase::class.java) // allowing main thread queries, just for testing .allowMainThreadQueries() .build() }
51. What’s next ?
52. Take away