Android Makers - Everything They Don't Tell You About Instant Apps

Transcript

1. Everything they don’t tell you about Instant Apps Jamie Adkins @jamieadkins95
2. Cricket World Cup 2019
3. CWC19 Quiz Instant App • Find the ICC app on the Play Store, and click “try now”. • “CWC” -> “T20WC”
4. Cricket World Cup 2019
5. Instant Apps in 2020?
6. Dynamic Features
7. What are Dynamic Features? • At Install Time ◦ Download this feature when the user installs my app from the Play Store. • Conditional ◦ Download this feature when the user installs my app from the Play Store if their device meets some conditions. • Instant enabled ◦ Download just this feature when the user clicks on a link. • On Demand ◦ Don’t download this feature at install time, download it later when the user wants to use that feature.
8. What are Dynamic Features? • At Install Time ◦ Download this feature when the user installs my app from the Play Store. • Conditional ◦ Download this feature when the user installs my app from the Play Store if their device meets some conditions. • Instant enabled ◦ Download just this feature when the user clicks on a link. • On Demand ◦ Don’t download this feature at install time, download it later when the user wants to use that feature.
9. Android Module Structure
10. Dynamic Feature Modules
11. Where We Started
12. Where We Started
13. Create a New Application Module
14. Install From the Play Store
15. Instant App Install
16. 4MB Download Limit
17. 4MB • Android/AndroidX - 1.2MB • Material Design - 500KB • Firebase - 60KB ◦ Google Play Services - 750KB • Common ICC/CWC assets - 500KB • CWC Fonts - 200KB • Common ICC/CWC code - 500KB • Quiz code & assets - 250KB • Total - 3.95MB
18. 4MB
19. 4MB
20. 15MB
21. Dependency Injection
22. Dependency Injection
23. Application Class - Before class IccApplication : DaggerApplication() { override fun onCreate() { super.onCreate() Timber.plant(CrashlyticsTree()) Fabric.with(this, Crashlytics()) } override fun applicationInjector() : AndroidInjector<out DaggerApplication> { return DaggerAppComponent.builder().create(this) } }
24. Application Class - Before class IccApplication : DaggerApplication() { override fun onCreate() { super.onCreate() Timber.plant(CrashlyticsTree()) Fabric.with(this, Crashlytics()) } override fun applicationInjector() : AndroidInjector<out DaggerApplication> { return DaggerAppComponent.builder().create(this) } }
25. Application Class - Before class IccApplication : DaggerApplication() { override fun onCreate() { super.onCreate() Timber.plant(CrashlyticsTree()) Fabric.with(this, Crashlytics()) } override fun applicationInjector() : AndroidInjector<out DaggerApplication> { return DaggerAppComponent.builder().create(this) } }
26. Conclusions • Don’t redo the Dagger Graph • Few dependencies actually need to be Singletons • We don’t need DaggerApplication
27. Proposal • AppComponent would stay in :app • Application class would move to :base, and it would provide a Singleton scoped CoreComponent • AppComponent would depend on CoreComponent for any Singletons • AppComponent would be built and scoped to the Activities in :app
28. https://medium.com/@jamieadkins95/ https://github.com/android/plaid
29. Android Manifest Merging
30. Manifest Merging <activity android:name="com.icccricket.quiz.QuizActivity" android:theme="@style/QuizTheme">
31. Manifest Merging <activity android:name="com.icccricket.quiz.QuizActivity" android:theme="@style/QuizTheme">
32. Manifest Merging <activity android:name="com.icccricket.quiz.QuizActivity" android:theme="@style/QuizTheme">
33. Manifest Merging <activity android:name="com.icccricket.quiz.QuizActivity" android:theme="@style/QuizTheme"> • Move all styles to base module ◦ Breaks separations of concern ◦ Impacts the 4MB download size limit • Create stub styles in :base
34. Stub Themes <!-- base/src/main/res/values/styles.xml --> <!-- Empty theme in base module --> <style name=”QuizTheme” /> https://github.com/android/plaid
35. Stub Themes <!-- base/src/main/res/values/styles.xml --> <!-- Empty theme in base module --> <style name=”QuizTheme” /> <!-- quiz/src/main/res/values/styles.xml --> <!-- Actual implementation in quiz dynamic feature module --> <style name="QuizTheme" parent="Theme.MaterialComponents"> <item name="colorPrimary">@color/cwc_primary</item> <item name="colorAccent">@color/cwc_secondary</item> ... https://github.com/android/plaid
36. Stub Themes Caveats • Must be shipping as an App Bundle ◦ APK builds will incorrectly use the stub style ◦ Distributing test builds as APKs? ◦ No split install support on < SDK 21 • We ended up moving all our styles to :base :( • But you don’t have to! Fixed in bundletool 0.13.4
37. Stub Themes Caveats • Must be shipping as an App Bundle ◦ APK builds will incorrectly use the stub style ◦ Distributing test builds as APKs ◦ No split install support on < SDK 21 • We ended up moving all our styles to :base :( • But you don’t have to! Fixed in bundletool 0.13.4
38. Bundletool 0.13.4 buildscript { repositories { google() jcenter() ... } dependencies { classpath "com.android.tools.build:bundletool:0.13.4" ... } ... }
39. Bundletool 0.13.4 • brew upgrade bundletool • Wait for Play Store to upgrade to 0.13.4 (April 2020 ) • https://github.com/google/bundletool/releases/tag/0.13.4 • https://github.com/google/bundletool/issues/68
40. Making Every Feature a Dynamic Feature
41. Resist the Urge!
42. Everything is a Dynamic Feature • Turn a feature into a dynamic feature only if it is going to be instant enabled/on demand • Feature on Feature Dependencies in AGP 4.0 • https://medium.com/@jamieadkins95/a-quick-look-at-feature-on-feat ure-dependencies-in-android-gradle-plugin-4-0-0-5828915d02d3 • 15MB download size limit is much more forgiving
43. Permissions
44. Cricket World Cup 2019
45. Cricket World Cup 2019
46. Permissions • Smaller set of permissions for Instant Apps • Can’t access external storage • Can’t share from internal storage either • You should share images using backend and a web url • For CWC we dropped the image • Scoped storage in Android 10/11?
47. Quick Fire Tips
48. Quick Fire Tips • Double check your proguard rules! • Use AGP 3.5 or higher (or 4.0 for feature-on-feature) • Use the APK Analyser in Android Studio • Test against the download size limit using xxxhdpi • Use the internal test track • Indexing may take 24 hours!
49. Should you build an Instant App?
50. Further Reading • Plaid Sample App - Google https://github.com/android/plaid • Ben Weiss https://medium.com/@keyboard surfer • Android Docs https://developer.android.com/to pic/google-play-instant @jamieadkins95 @jamieadkins95
51. R.java Files
52. R.java Files • In normal project you can use the same R.java file to reference everything • In dynamic features, you need to use the base application module’s R.java file for common resources • Otherwise you’ll get an ‘unresolved reference’ error at compile time • IDE doesn’t see the error • Can use Kotlin aliases to neaten this up
53. R.java Files import com.icccricket.quiz.R import com.icccricket.coreapplication.R as CoreR val color = ContextCompat.getColor(context, CoreR.color.cwc_primary)
54. Constraint Layout
55. Groups/Barriers <android.support.constraint.Group android:id="@+id/group" android:layout_width="wrap_content" android:layout_height="wrap_content" android:visibility="visible" app:constraint_referenced_ids="button4,button9" />
56. Groups/Barriers • Programatically set the view ids group.setReferencedIds(arrayOf(R.id.button4, R.id.button9)) Fixed in Constraint Layout 2.0.0-beta2 https://androidstudio.googleblog.com/2019/06/constraintlayout-200-be ta-2.html