Kotlin + RxBinding = ❤️

Lightning talk from GDG Devfest Hamburg 2016

Transcript

1. Kotlin + RxBinding = Lovis Möller @lovisbrot #devfestHH
2. RxBinding • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
3. RxBinding • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island • Make your Android Views reactive
4. RxBinding • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island • Make your Android Views reactive RxView.clicks(myView) .filter(…) .flatMap(…) .subscribe(…)
5. RxBinding • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island • Make your Android Views reactive RxView.clicks(myView) .filter(…) .flatMap(…) .subscribe(…) • JakeWharton
6. RxBinding • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island • Make your Android Views reactive RxView.clicks(myView) .filter(…) .flatMap(…) .subscribe(…) • JakeWharton ✔
7. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
8. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
9. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
10. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
11. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
12. Kotlin • JVM language • developed by JetBrains • Null safety, immutability • Extension functions • It’s an Island
13. Kotlin - Extension Functions fun String?.orEmpty(): String { if(this == null) return "" return this }
14. Kotlin - Extension Functions fun String?.orEmpty(): String { } if(this == null) return "" return this }
15. Kotlin - Extension Functions fun String?.orEmpty(): String { if(this == null) return "" return this }
16. Kotlin - Extension Functions fun String?.orEmpty(): String { if(this == null) return "" return this } val name: String? = null val option = name.orEmpty()
17. Kotlin - Extension Functions fun String?.orEmpty(): String { return this ?: "" } val name: String? = null val option = name.orEmpty()
18. Kotlin - Extension Functions fun String?.orEmpty() = this ?: "" return this ?: "" } val name: String? = null val option = name.orEmpty()
19. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 />
20. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> EditText name = (EditText) findViewById(R.id.editName);
21. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> @BindView(R.id.editName) EditText name;
22. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> val name: TextView by bindView(R.id.first_name)
23. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> import kotlinx.android.synthetic.main.activity_main.*
24. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> import kotlinx.android.synthetic.main.activity_main.* ... editName.text = "Lovis"
25. Get that View! <EditText
 android:id="@+id/editName"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 /> import kotlinx.android.synthetic.main.activity_main.* ... editName.text = "Lovis" //no findViewById necessary!
26. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
27. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
28. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
29. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
30. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
31. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
32. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" }
33. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" } static method looks ugly
34. Java + RxBinding EditText name = ... RxTextView.textChanges(name) .debounce(400, TimeUnit.MILLISECONDS) .flatMap(text -> api.sendToServer(text)) .observeOn(AndroidSchedulers.mainThread()) .subscribe( this::handleResponse, this::handleError ); return this ?: "" } NOT RxEditText! static method looks ugly
35. Java + RxBinding • RxAbsListView • RxAdapter • RxAdapterView • RxAutoCompleteTextView • RxCheckedTextView • RxCompoundButton • RxProgressBar • RxRadioGroup • RxRecyclerView • RxSeekBar • RxView • RxViewGroup • RxSnackbar • RxAppBarLayout • RxDrawerLayout • RxNestedScrollView • RxSwipeRefreshLayout • RxSearchView • RxToolbar • …
36. Java + RxBinding • RxButton → clicks() ❓ • RxEditText RxTextView → textChanges()
37. Java + RxBinding • RxButton RxView → clicks() • RxEditText RxTextView → textChanges()
38. Java + RxBinding • RxButton RxView → clicks() • RxEditText RxTextView → textChanges()
39. Java + RxBinding • RxButton RxView → clicks() • RxEditText RxTextView → textChanges()
40. Kotlin + RxBinding val name: EditText = ... name.textChanges() .debounce(400, TimeUnit.MILLISECONDS) .flatMap { text -> api.sendToServer(text) } .observeOn(AndroidSchedulers.mainThread()) .subscribe( { handleResponse(it) }, { handleError(it) } ); return this ?: "" }
41. Kotlin + RxBinding val name: EditText = ... name.textChanges() .debounce(400, TimeUnit.MILLISECONDS) .flatMap { text -> api.sendToServer(text) } .observeOn(AndroidSchedulers.mainThread()) .subscribe( { handleResponse(it) }, { handleError(it) } ); return this ?: "" } extension method
42. Kotlin + RxBinding val name: EditText = ... name.textChanges() .debounce(400, TimeUnit.MILLISECONDS) .flatMap { text -> api.sendToServer(text) } .observeOn(AndroidSchedulers.mainThread()) .subscribe( { handleResponse(it) }, { handleError(it) } ); return this ?: "" } extension method No need to know!
43. Kotlin + RxBinding val button: Button = ... val buttonClicks = button.clicks().share() buttonClicks.subscribe { //do something useful } buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
44. Kotlin + RxBinding val button: Button = ... // in Java: Observable<Void> buttonClicks = ... val buttonClicks = button.clicks().share() buttonClicks.subscribe { //do something useful } buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
45. Kotlin + RxBinding val button: Button = ... val buttonClicks = button.clicks().share() buttonClicks.subscribe { //do something useful } buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
46. Kotlin + RxBinding val button: Button = ... val buttonClicks = button.clicks().share() buttonClicks.subscribe { //do something useful } buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
47. Kotlin + RxBinding val button: Button = ... val buttonClicks = button.clicks().share() buttonClicks.subscribe { //do something useful } buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
48. Kotlin + RxBinding val button: Button = ... val buttonClicks = button.clicks().share() val sub1 = buttonClicks.subscribe { //do something useful } val sub2 = buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
49. Kotlin + RxBinding val button: Button = ... val compositeSub = CompositeSubscription() val buttonClicks = button.clicks().share() val sub1 = buttonClicks.subscribe { //do something useful } val sub2 = buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
50. Kotlin + RxBinding val button: Button = ... val compositeSub = CompositeSubscription() val buttonClicks = button.clicks().share() compositeSub += buttonClicks.subscribe { //do something useful } compositeSub += buttonClicks.subscribe { //two listeners on one button! } return this ?: "" }
51. • kotlinlang.org • try.kotlinlang.org • leanpub.com/kotlin-for-android-developers • https://github.com/JakeWharton/RxBinding Lovis Möller @lovisbrot #devfestHH
52. println("Thanks a lot!") Lovis Möller @lovisbrot #devfestHH