AndroidSummit2017_Best practices in building mobile libraries

Best practices in building mobile libraries

Transcript

1. VONAGE CONFIDENTIAL 1 Best practices in building mobile libraries Emma Tresanszki August 25, 2017
2. VONAGE CONFIDENTIAL 2 About me
3. VONAGE CONFIDENTIAL 3 • SDK vs Library • Developer perspective - managing dependencies - managing permissions • Creating Libraries - responsibility - failure handling - publish Agenda
4. VONAGE CONFIDENTIAL 4 SDK or Library?
5. VONAGE CONFIDENTIAL 5 - A library < a chunk of reusable code > - An SDK < is still a library > (often with extra tool applications, data files and sample code) SDK vs Library
6. VONAGE CONFIDENTIAL 6 Why do we need one?
7. VONAGE CONFIDENTIAL 7 Examples
8. VONAGE CONFIDENTIAL 8 Examples: 2FA phone number verifications
9. VONAGE CONFIDENTIAL 9 Why not?
10. VONAGE CONFIDENTIAL 10 Developer = library User
11. VONAGE CONFIDENTIAL 11 Managing dependencies
12. VONAGE CONFIDENTIAL 12 - In Gradle, dynamic versions use the +sign - But what has changed? But which dependency?
13. VONAGE CONFIDENTIAL 13 - Add nondeterminism to the build: - Behaviour changes - “But it works on my machine” - Difficult to revert - Fix it Dynamic dependencies are ‘evil’
14. VONAGE CONFIDENTIAL 14 - Don’t let libraries silently add permissions to your app. Permissions
15. VONAGE CONFIDENTIAL 15 Permissions
16. VONAGE CONFIDENTIAL 16 - Disable manifest merging Permissions
17. VONAGE CONFIDENTIAL 17 Developer = library creator
18. VONAGE CONFIDENTIAL 18 - I/O 2013 - /AndroidManifest.xml (mandatory) - /classes.jar (mandatory) - /res/ (mandatory) - /R.txt (mandatory) - /assets/ (optional) - /libs/*.jar (optional) - /proguard.txt (optional) - /lint.jar (optional) What is aar?
19. VONAGE CONFIDENTIAL 19 - Fail fast when rejecting invalid params. Actually not all the time! - Do not discard future capabilities. - Flexibility: let the API handle rejections instead. Design phase: responsibility
20. VONAGE CONFIDENTIAL 20 Design phase: error handling
21. VONAGE CONFIDENTIAL 21 - 3rd party dependencies, or not at all - ex: libphonenumber in a 2FA phone verification SDK (~500kb) Design phase: library size
22. VONAGE CONFIDENTIAL 22 - Devs should choose permissions - which features? - /AndroidManifest.xml - App to request permission grant - Library to check runtime permissions and block the feature otherwise. Design phase: permissions
23. VONAGE CONFIDENTIAL 23 Design phase: UI components - Fabric Digits Button and themes
24. VONAGE CONFIDENTIAL 24 Publish to Central repo
25. VONAGE CONFIDENTIAL 25 gradle.properties, build.gradle
26. VONAGE CONFIDENTIAL 26 Requirements ~/.gradle/gradle.properties - GAV - Signing - SCM info
27. VONAGE CONFIDENTIAL 27 Requirements ~/.gradle/gradle.properties
28. VONAGE CONFIDENTIAL 28 ~/.gradle/gradle.build
29. VONAGE CONFIDENTIAL 29 ~/.gradle/gradle.build
30. VONAGE CONFIDENTIAL 30 $ gradle uploadArchives
31. VONAGE CONFIDENTIAL 31 run task
32. VONAGE CONFIDENTIAL 32
33. VONAGE CONFIDENTIAL 33 Sonatype: Release repository
34. VONAGE CONFIDENTIAL 34 Done!
35. VONAGE CONFIDENTIAL 35 • Version numbers are used to encode compatibility for the API. • Semantic versioning {major}.{minor}.{bugfix} • Initial development phase: 0.1.0 • How to deprecate? ◦ minor ◦ major transition Versioning
36. VONAGE CONFIDENTIAL 36 • Superstition ◦ Office 2007 internal v12 -> Office 2010 has internal v14. ◦ Corel Graphic Suite v13 marketed as X3 ◦ Nokia jumped from S60 3rd -> S60 5th Edition Versioning
37. VONAGE CONFIDENTIAL 37
38. VONAGE CONFIDENTIAL 38 How do I make a good CHANGELOG? Definition: A file which contains a curated, chronologically ordered list of notable changes for each version of a project. Principles • Changelogs are for humans, not machines. • There should be an entry for every single version. • The latest version comes first. • The release date of each versions is displayed.
39. VONAGE CONFIDENTIAL 39 How do I make a good CHANGELOG? Group changes by type • ADDED • CHANGED • FIXED • REMOVED • DEPRECATED • SECURITY • UNRELEASED
40. VONAGE CONFIDENTIAL 40 - Documentation - copy-paste a working demo - good API reference - advanced usage More stuff
41. VONAGE CONFIDENTIAL 41 • Automated Gradle project deployment to Sonatype OSS repository • Maven Repository Usage Guide • http://www.leveluplunch.com/java/examples/parse-phone-number-from-string/ • http://www.theappguruz.com/blog/integrate-paypal-in-android//dropbox • http://blog.danlew.net/2015/09/09/dont-use-dynamic-versions-for-your-dependencies/ • https://github.com/olivierlacan/keep-a-changelog • http://skife.org/src/design/libraries/2011/12/14/library_versioning.html • http://keepachangelog.com/en/1.0.0/ • https://en.wikipedia.org/wiki/Software_versioning • http://blog.mockito.org/2014/10/maven-central-vs-bintray.html • https://developer.android.com/studio/build/manifest-merge.html References
42. VONAGE CONFIDENTIAL 42 Thank you :) twitter @EmmaTresanszki Github @EmmaChristine slides Thank you! :) twitter @EmmaTresanszki github @EmmaChristine speakerdeck @EmmaTresanszki