1. The document discusses different approaches for managing internal library dependencies in Android projects, including having a single repository with one or multiple gradle modules, using git submodules across multiple repositories, and linking repositories with Maven through a local Artifactory server. 2. It provides details on setting up each approach, such as configuring gradle and git settings, and publishing and referencing libraries on Artifactory. 3. The advantages and disadvantages of each approach are outlined, such as clear separation of concerns versus complexity of multiple repositories and commits.

1. Internal Library Dependency
Management
Kelly Shuster
Android Developer, iTriage

2. Internal Library
Dependency Management
@KellyShuster

3. @KellyShuster

4. @KellyShuster

9. 1. Single Repository, Single Gradle Module

10. 1. Single Repository, Single Gradle Module
2. Single Repository, Multiple Gradle Modules

11. 1. Single Repository, Single Gradle Module
2. Single Repository, Multiple Gradle Modules
3. Multiple Repositories, Linked by Git

12. 1. Single Repository, Single Gradle Module
2. Single Repository, Multiple Gradle Modules
3. Multiple Repositories, Linked by Git
4. Multiple Repositories, Linked by Maven

13. Single Repository,
Single Gradle Module

14. dependency-sample
app

17. Team Workflow
Single branch
Pull Request

18. Pros
Easy to understand
Everything in a central location
Straightforward to obtain code & debug

19. Cons
Library is not separate component
Can’t be shared w/ another team
Can’t be versioned independently
No explicit separation of concerns.

22. Single Repository,
Multiple Gradle Modules

23. dependency-sample
app mylibrary

30. settings.gradle
include ':app', ':mylibrary'

31. settings.gradle
include ':app', ':mylibrary'

32. build.gradle (app)
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
compile project(':mylibrary')
}

33. build.gradle (app)
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
compile project(':mylibrary')
}

34. Team Workflow
Single branch
Pull Request

35. Pros
Easy procedure; hard to mess up
Added some separation of concerns

36. Cons
Library is not separate component
Can’t be shared w/ another team
Can’t be versioned independently

37. Multiple Repositories,
Linked Using Git

38. Git Submodules

39. dependency-sample dependency-sample-lib
app mylibrary

45. How do you set it up?

46. git submodule add <lib-repo>

47. 123789d
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48. 78c7046
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51. [submodule "dependency-sample-library"]
path = dependency-sample-library
url = https://github.com/KioKrofovitch/dependency-sample-library.git
.gitmodules

52. Add Gradle References

53. settings.gradle
include ':app'
include ':dependency-sample-library:mylibrary'

54. settings.gradle
include ':app'
include ':dependency-sample-library:mylibrary'

55. build.gradle (app)
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile project(':dependency-sample-library:mylibrary')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
}

56. build.gradle (app)
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile project(':dependency-sample-library:mylibrary')
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
}

57. Check Submodule Status

58. git submodule

62. 78c7046
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63. How do you get code?

64. git clone <repo> --recursive

65. git clone <repo>
git submodule init
git submodule update

66. git checkout <branch>
git submodule init
git submodule update

67. git checkout <branch>

71. git submodule init

74. git submodule update

77. Upstream changes

81. Changing the library

83. ff07597
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88. Committing on a Detached Head

90. How it happens

92. 1bd7125
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96. 1bd7125
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97. 1bd7125
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98. How to recover

102. Removing Submodules

105. .gitmodules
.git/modules

106. Team Workflow

107. Step 1 - Shell & Library
1. Create branch for shell
2. Create branch for library
3. Make and test shell & library changes
simultaneously

108. Step 2 - Library
1. Pull request / code review lib changes
2. Merge pull request

109. Step 3 - Shell
1. Update shell branch to point to latest
library master commit
2. Pull request / code review shell changes
3. Merge pull request

110. Pros
Clear separation of concerns

111. Pros
Clear separation of concerns
Library is in separate repo! Can be shared!

112. Pros
Clear separation of concerns
Library is in separate repo! Can be shared!
“Versioning” brought to you by git

113. Pros
Clear separation of concerns
Library is in separate repo! Can be shared!
“Versioning” brought to you by git
“Version” determined by shell

114. Pros
One Android Studio Project

115. Pros
One Android Studio Project
Easily step into code with debugger

116. Pros
One Android Studio Project
Easily step into code with debugger
Submodule maintains its own git history

117. Cons
Magic is involved

118. Cons
Magic is involved
Very easy to mess up, in multiple spots:

119. Cons
Magic is involved
Very easy to mess up, in multiple spots:
Working with a detached head
Pulling down latest submodule
Adding & tracking submodule reference

120. Cons
Multi-step PR & merge

121. Cons
Multi-step PR & merge
Library versions are commit SHAs

124. Multiple Repositories,
Linked Using Maven

125. Artifactory

126. dependency-sample dependency-sample-lib
app
Artifactory
mylibrary

127. dependency-sample dependency-sample-lib
app mylibrary
Artifactory
Reference

128. dependency-sample dependency-sample-lib
app
Artifactory
Publish
mylibrary

131. Artifactory Local Setup

132. Install Java 8
Download / unzip artifactory
Run bin/artifact.sh
http://localhost:8081/artifactory/webapp/#/home

133. Publishing

135. build.gradle (project level)
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:1.3.0'
classpath "org.jfrog.buildinfo:build-info-extractor-gradle:3.1.1"
// NOTE: Do not place your application dependencies here; they
// belong in the individual module build.gradle files
}
}

136. build.gradle (project level)
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:1.3.0'
classpath "org.jfrog.buildinfo:build-info-extractor-gradle:3.1.1"
// NOTE: Do not place your application dependencies here; they
// belong in the individual module build.gradle files
}
}

137. build.gradle (mylibrary)
apply plugin: 'com.android.library'
apply plugin: 'com.jfrog.artifactory'
apply plugin: 'maven-publish'
def packageName = 'com.kiodev.myArtLibrary'
def versionMajor = '1'
def versionMinor = '0'
def versionPatch = '0'
def libraryVersion = "${versionMajor}.${versionMinor}.${versionPatch}"
android { … }
dependencies { … }
publishing { … }
artifactory { … }

138. build.gradle (mylibrary)
apply plugin: 'com.android.library'
apply plugin: 'com.jfrog.artifactory'
apply plugin: 'maven-publish'
def packageName = 'com.kiodev.myArtLibrary'
def versionMajor = '1'
def versionMinor = '0'
def versionPatch = '0'
def libraryVersion = "${versionMajor}.${versionMinor}.${versionPatch}"
android { … }
dependencies { … }
publishing { … }
artifactory { … }

139. build.gradle (mylibrary)
apply plugin: 'com.android.library'
apply plugin: 'com.jfrog.artifactory'
apply plugin: 'maven-publish'
def packageName = 'com.kiodev.myArtLibrary'
def versionMajor = '1'
def versionMinor = '0'
def versionPatch = '0'
def libraryVersion = "${versionMajor}.${versionMinor}.${versionPatch}"
android { … }
dependencies { … }
publishing { … }
artifactory { … }

140. build.gradle (mylibrary)
apply plugin: 'com.android.library'
apply plugin: 'com.jfrog.artifactory'
apply plugin: 'maven-publish'
def packageName = 'com.kiodev.myArtLibrary'
def versionMajor = '1'
def versionMinor = '0'
def versionPatch = '0'
def libraryVersion = "${versionMajor}.${versionMinor}.${versionPatch}"
android { … }
dependencies { … }
publishing { … }
artifactory { … }

141. build.gradle (mylibrary)
publishing {
publications {
aar(MavenPublication) {
groupId packageName
version = libraryVersion
artifactId project.getName()
// Tell maven to prepare the generated "*.aar" file for publishing
artifact("$buildDir/outputs/aar/${project.getName()}-release.aar")
}
}
}

142. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository {
...
}
defaults {
...
}
}
}

143. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository {
// The Artifactory repository key to publish to
repoKey = 'libs-release-local'
username = "admin"
password = "password"
}
defaults { … }
}
}

144. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository {
// The Artifactory repository key to publish to
repoKey = 'libs-release-local'
// More sophistication with gradle.properties
username = artifactory_user
password = artifactory_password
}
defaults { … }
}
}

145. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository { ... }
defaults {
// Tell the Artifactory Plugin which artifacts to publish
publications('aar')
publishArtifacts = true
// Properties to be attached to the published artifacts.
properties = ['qa.level': 'basic', 'dev.team': 'core']
// Publish generated POM files to Artifactory (true by default)
publishPom = true
}
}
}

146. gradle assemble artifactoryPublish

150. Referencing

151. build.gradle (project level)
allprojects {
repositories {
jcenter()
maven {
url "http://localhost:8081/artifactory/libs-release-local"
}
}
}

152. build.gradle (project level)
allprojects {
repositories {
jcenter()
maven {
url "http://localhost:8081/artifactory/libs-release-local"
}
}
}

153. build.gradle (project level)
allprojects {
repositories {
jcenter()
maven {
url "http://localhost:8081/artifactory/libs-release-local"
// More sophistication with gradle.properties
credentials {
username = artifactory_user
password = artifactory_password
}
}
}
}

154. build.gradle (app)
android {
…
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
compile(group: 'com.kiodev.myArtLibrary', name: 'mylibrary',
version: '1.0.0', ext: 'aar')
}

155. build.gradle (app)
android {
…
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:23.0.1'
compile 'com.android.support:design:23.0.1'
compile(group: 'com.kiodev.myArtLibrary', name: 'mylibrary',
version: '1.0.0', ext: 'aar')
}

156. gradle build --refresh-dependencies

159. Debugging

160. Sources Jar

161. Artifactory Sources Jar
Upload sources jar

162. Artifactory Sources Jar
Upload sources jar
Sources jar download isn’t automatic

163. Artifactory Sources Jar
Upload sources jar
Sources jar download isn’t automatic
Getting most up to date is confusing

164. Snapshot

165. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository {
// The Artifactory repository key to publish to
repoKey = 'libs-release-local'
// More sophistication with gradle.properties
username = artifactory_user
password = artifactory_password
}
defaults { … }
}
}

166. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
publish {
repository {
// The Artifactory repository key to publish to
repoKey = 'libs-release-local'
// More sophistication with gradle.properties
username = artifactory_user
password = artifactory_password
}
defaults { … }
}
}

167. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
def repoName = ""
if (project.version.endsWith('-SNAPSHOT')) {
repoName = 'libs-snapshot-local'
} else {
repoName = 'libs-release-local'
}
publish { ... }
}

168. build.gradle (mylibrary)
artifactory {
contextUrl = 'http://localhost:8081/artifactory'
def repoName = ""
if (project.version.endsWith('-SNAPSHOT')) {
repoName = 'libs-snapshot-local'
} else {
repoName = 'libs-release-local'
}
publish { ... }
}

170. Publishing Bandit

171. Github
Code changes
& commits

172. Github Github
Code changes
& commits
Pull request
& merge

173. Github Github Artifactory
Code changes
& commits
Pull request
& merge Publish

174. Github Artifactory
Code changes
& commits
Publish

175. Github Artifactory
Code changes
Publish

176. Team Workflow

177. Step 1 - Library
Create branch
Make & test library changes
Increase version in gradle file
Pull request / code review
Merge pull request
Publish library to artifactory

178. Step 2 - Shell
Create branch
Make & test shell changes
Increase version in gradle file
Pull request / code review
Merge pull request

179. Pros
Clear separation of concerns

180. Pros
Clear separation of concerns
Library is in sep repo! Can be shared!

181. Pros
Clear separation of concerns
Library is in sep repo! Can be shared!
Versioning is human readable / determined

182. Pros
Clear separation of concerns
Library is in sep repo! Can be shared!
Versioning is human readable / determined
Benefits of JAR / AAR

183. Cons
Versioning has zero tie to git!
Easy to lose track of what is where

184. Cons
Versioning has zero tie to git!
Easy to lose track of what is where
Low security
You can publish anything…
You can wipe out an old version

185. Cons
Sources jar is difficult to locate and use

186. Cons
Sources jar is difficult to locate and use
No guarantee your sources jar matches the
artifact you are referencing

187. Cons
Sources jar is difficult to locate and use
No guarantee your sources jar matches the
artifact you are referencing
Makes stepping through code hard

188. Your Team

189. Pick what works for your team
Size of team

190. Pick what works for your team
Size of team
Frequency of library changes

191. Pick what works for your team
Size of team
Frequency of library changes
Library reuse or sharing

192. Pick what works for your team
Size of team
Frequency of library changes
Library reuse or sharing
Importance of aar

193. Pick what works for your team
Size of team
Frequency of library changes
Library reuse or sharing
Importance of aar
Team knowledge of git

194. @KellyShuster
https://github.com/KioKrofovitch/
dependency-sample
dependency-sample-library

195. Resources
Git submodule
https://git-scm.com/docs/git-submodule
https://git-scm.com/book/en/v2/Git-Tools-Submodules
Artifactory Open Source
https://www.jfrog.com/open-source/
Artifactory Professional
https://www.jfrog.com/artifactory/
Artifactory OS Tutorial
https://jeroenmols.github.io/blog/2015/08/06/artifactory/

196. Photo Credits
Android Robot
https://commons.wikimedia.org/wiki/File:Android_robot.svg
Trinity College Library
https://en.wikipedia.org/wiki/Trinity_College,_Dublin#/media/File:Long_Room_Interior,
_Trinity_College_Dublin,_Ireland_-_Diliff.jpg
Ruby
http://nicholasjohnson.com/ruby/
Clean Desk
http://www.levo.com/articles/career-advice/what-your-desk-says-about-you
Messy Desk
http://www.telegraph.co.uk/news/newstopics/howaboutthat/10225664/Having-a-messy-desk-makes-you-more-
creative.html
Headless Horseman Gif
https://www.lovethisgif.com/tag/headless+horseman
Ghost
http://38.media.tumblr.com/d30fe069cc48e11eeb31ae08293a159e/tumblr_nbtdxg9d6n1szf0nzo1_250.gif

197. Photo Credits
Atreyu & Horse
http://5cities6women.com/2014/04/06/happy-30th-birthday-neverending-story/
Neverending Story Book
http://www.dailyrecord.co.uk/entertainment/tv-radio/flashback-friday-neverending-story-proves-4948514
Unicorn w/ Rainbows
http://souloftruth.com/the-race-to-nowhere/
Falcor & Atreyu
http://filmconnoisseur.blogspot.com/2010/08/never-ending-story-book-review.html
John Wayne
http://patch.com/california/sanclemente/best-ways-recycle-water-during-californias-dry-spell
Space Pic
http://wallpapershidef.com/outer-space-desktop-wallpaper.html
Computer
https://commons.wikimedia.org/wiki/File:Gnome-computer.svg