Key learnings and pitfalls from building mobile SDK

Are you working on the client library? Or design a public API for the module that is going to be used by other team or department?

In this session, Vitality will share his experience and key learnings from building a set of mobile SDKs. The session will be interesting for Android and iOS developers who want to learn what makes client library great. What are the best practices and common pitfalls in public API design. What is important, only programming API you expose or also ecosystem around?

Transcript

1. @zasadnyy Or what did we learn in the last 4 years Building mobile SDK Vitaliy Zasadnyy Head of Mobile @ GetSocial
2. @zasadnyy Integrated SDK. But it doesn’t work.
3. Developer. GDG Lead. Public Speaker. @zasadnyy
7. LISTEN
8. SDK Lifecycle
9. @zasadnyy SDK Lifecycle Develop 1
10. @zasadnyy
11. @zasadnyy SDK Lifecycle Develop 1
12. @zasadnyy SDK Lifecycle Develop 1 Integrate 2 Support 3 Update 4
13. Develop 1
14. @zasadnyy Start shaping your API Use Cases Examples Integration Tests
15. @zasadnyy Cost of fixing issue
16. @zasadnyy Cost of fixing issue Spend 10x more time on line of examples comparing to production code
17. @zasadnyy NOT SURE? DROP IT!
18. @zasadnyy IS BETTER LESS CODE
19. @zasadnyy Boilerplate ➡ Copy/Paste ➡ Bugs Why?
20. @zasadnyy GetSocial Analytics problem Almost all our clients mis-integrate analytics <receiver android:name="im.getsocial.InstallReferrerReceiver"> <intent-filter> <action android:name="com.android.vending.INSTALL_REFERRER"/> </intent-filter> </receiver>
21. @zasadnyy How to solve? AndroidManifest merging Gradle plugin Android Studion plugin …
22. @zasadnyy IS BETTER LESS CODE
23. @zasadnyy API SURPRISES AVOID
24. @zasadnyy Avoid API surprises Thread.interrupted() Returns the current interrupted status and then clears it
25. @zasadnyy Avoid API surprises
26. @zasadnyy Avoid API surprises Thread.interrupted() Returns the current interrupted status and then clears it
27. @zasadnyy Make the API to your library as boring as possible - Chris Sells, Google
28. @zasadnyy No SetListener() in C# void SetOnInviteFriendsListener ( Action onInviteFriendsIntent, Action<int> onFriendsInvited)
29. @zasadnyy Much better API event Action OnInviteFriendsIntent event Action<int> OnFriendsInvited
30. @zasadnyy Follow platform guidelines Mimic core API Avoid introducing new concepts
31. @zasadnyy ? Library is crashing you app?
32. @zasadnyy
33. @zasadnyy CRASH HOST APP NEVER
34. @zasadnyy GetSocial approach Rx @Nullable PMD / FindBugs / Lint
35. @zasadnyy Rx chains Observable .just(MetaDataKey.APP_ID) .map(ValidateAppIdFunc.create()) .flatMap(TrackInstallFunc.create()) ... .subscribe((result) -> { ... }, (throwable) -> { // all exceptions end up here } );
36. @zasadnyy Rx chains Observable .just(MetaDataKey.APP_ID) .map(ValidateAppIdFunc.create()) .flatMap(TrackInstallFunc.create()) ... .subscribe((result) -> { ... }, (throwable) -> { // all exceptions end up here } );
37. @zasadnyy
38. @zasadnyy INTERNALS HIDE
39. @zasadnyy Hide internals
40. @zasadnyy Hide internals Use .internal package Keep everything private by default
41. @zasadnyy There is much more!
42. Integrate
43. @zasadnyy ? What is important to developers?
44. @zasadnyy SIZE
45. @zasadnyy List information about Library size Method count Proguard rules
46. @zasadnyy COMPATIBILITY
47. @zasadnyy Keep compatibility Select minimum supported platform version. After detailed market research Update maximum supported version. Continuously
48. @zasadnyy SUPPORT
49. @zasadnyy Give a voice to your users GitHub issue tracker Intercom Support email …
50. @zasadnyy Get ready to repetitive questions
51. @zasadnyy DOCS
52. @zasadnyy Key parts Step by step tutorials Product guides API Reference
53. @zasadnyy
54. @zasadnyy
55. @zasadnyy
56. @zasadnyy What is wrong with snippet? CurrentUser user = getSocial.getCurrentUser();
57. @zasadnyy What is wrong with snippet? CurrentUser user = getSocial.getCurrentUser();
58. @zasadnyy ALL SNIPPETS MUST COMPILE
59. @zasadnyy Better snippet import im.getsocial.sdk.GetSocial; import im.getsocial.sdk.CurrentUser; ... CurrentUser user = GetSocial.getInstance().getCurrentUser();
60. @zasadnyy ? Favourite source of copy / paste code?
61. @zasadnyy
62. @zasadnyy DEMOS
63. @zasadnyy Demo apps Make demos well documented Keep SDK integration code separated
64. Support
65. @zasadnyy ? You’ve got support request. Now what?
66. @zasadnyy Two types of problems Integration time problems End-user side problems
67. @zasadnyy Solving integration time problems Easy way to get SDK version Debug SDK configuration Unique log tag Actionable errors
68. @zasadnyy Actionable errors public class GetSocialException extends RuntimeException { private final int _errorCode; … }
69. @zasadnyy Actionable errors public class GetSocialException extends RuntimeException { private final int _errorCode; … }
70. @zasadnyy Solving end-user side problems Comprehensive logs Errors analytics
71. @zasadnyy Solving end-user side problems private void trackError(GetSocialException exception) { ... AnalyticsTrackManager.trackAnalyticsEvent( AnalyticsEventDetails.Name.SDK_ERROR, eventProperties); }
72. @zasadnyy s THINK ABOUT SUPPORT AHEAD
73. Update
74. @zasadnyy ? Why developers update SDKs?
75. @zasadnyy Update. Build. And…
76. @zasadnyy
77. @zasadnyy UPDATES SMOOTH
78. @zasadnyy Backward compatibility Use @Deprecation cycle /** * @deprecated use {@link #getAllIdentities()} instead. * Method will be removed in SDK v5.0.0. */ @Deprecated public List<String> getIdentities() { ... }
79. @zasadnyy Semantic versioning v4.5.1 Major Minor Bugfix
80. @zasadnyy Versioned packages import okhttp3; import im.getsocial.sdk6;
81. @zasadnyy Versioned packages import okhttp3; import im.getsocial.sdk6; Partial transition A/B testing
82. @zasadnyy Changelog Fixed issues Added features Compatibility changes API changes
83. @zasadnyy
84. To sum up
85. @zasadnyy SDK Lifecycle Develop 1
86. @zasadnyy SDK Lifecycle Develop Integrate Support Update 1 2 3 4
87. @zasadnyy Develop 1 Integrate 2 Support 3 Update 4 Not sure? Drop it! Never crash Be your own customer Think ahead Smooth
88. @zasadnyy API can be you biggest asset of liability - Joshua Bloch Put yourself in your customer’s shoes - Cesare Rocchi
89. @zasadnyy Happy dog Make developers happy again.
90. @zasadnyy @zasadnyy / zasadnyy.com Questions? Mulțumesc!