Successfully modularizing your app

Video: https://www.youtube.com/watch?v=9eikhwWehWk

Modularizing your app seems to be all the hype these days. But why should you actually care? What are the benefits for you and your team? How should a modularized app look like? And how do you start splitting your app?

In this talk, you will learn why modularization matters and how a modularized architecture looks like. We'll study a real-life example project and investigate how modules are set up, organized and configuration is shared across modules. Finally, you'll learn how you can start modularizing your existing app and I'll share what lessons we learned while doing so at Philips Hue.

Articles:
1. why - http://bit.ly/modularization_why
2. architecture - http://bit.ly/modularization_architecture
3. example - http://bit.ly/modularization_example
4. how - http://bit.ly/modularization_how
5. lessons - http://bit.ly/modularization_lessons

Source code: http://bit.ly/modularization_code #androiddev #mobiconf

Transcript

1. @MOLSJEROEN SUCCESSFULLY MODULARIZING APPS
2. @MOLSJEROEN @MOLSJEROEN @MOLSJEROEN
3. @MOLSJEROEN WHY MODULARIZATION ARCHITECTURE HOW TO APPROACH LESSONS LEARNED
4. WHY
5. @MOLSJEROEN 1. SPEED UP BUILDS Gradle does two things to speed up builds • Avoid work/caching • Parallellization Need smaller items of work
6. @MOLSJEROEN 1. SPEED UP BUILDS: SMALLER ITEMS OF WORK
7. @MOLSJEROEN 1. SPEED UP BUILDS: SINGLE MODULE
8. @MOLSJEROEN 1. SPEED UP BUILDS: MULTI MODULE
9. @MOLSJEROEN 1. SPEED UP BUILDS: MULTI MODULE
10. @MOLSJEROEN 2. ALLOW ON DEMAND DELIVERY
12. @MOLSJEROEN 2. ALLOW ON DEMAND DELIVERY At-install delivery On demand delivery Conditional delivery Instant delivery Need to split up app Support future requirements
13. @MOLSJEROEN 3. SIMPLIFY DEVELOPMENT APP
14. @MOLSJEROEN 3. SIMPLIFY DEVELOPMENT APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
15. IT’S EASIER TO BUILD SEVERAL SMALL THINGS THAN TO BUILD ONE BIG THING Unknown
16. @MOLSJEROEN 3. SIMPLIFY DEVELOPMENT Clear contracts between modules • Less spaghetti code • Fewer cascading changes • Easier in-module refactoring Easy to understand code Cheaper maintenance
17. @MOLSJEROEN 4. REUSE MODULES
18. @MOLSJEROEN 4. REUSE MODULES: MULTIPLE APPS APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 APP 2
19. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 APP 2 4. REUSE MODULES: MULTIPLE APPS
20. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 APP 2 FEATURE X FEATURE X 4. REUSE MODULES: MULTIPLE APPS
21. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 APP 2 FEATURE X FEATURE X 4. REUSE MODULES: MULTIPLE APPS
22. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 SDK LIBRARY 2 4. REUSE MODULES: SDK
23. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 SDK LIBRARY 2 4. REUSE MODULES: SDK
24. @MOLSJEROEN APP 1 EXPOSED FEATURE WITH INTENT FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 4. REUSE MODULES: EXPOSE FEATURES
25. @MOLSJEROEN APP 1 EXPOSED FEATURE WITH INTENT FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 4. REUSE MODULES: EXPOSE FEATURES
26. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 AWESOME GITHUB LIBRARY LIBRARY 2 4. REUSE MODULES: OPEN SOURCE
27. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 AWESOME GITHUB LIBRARY LIBRARY 2 4. REUSE MODULES: OPEN SOURCE
28. @MOLSJEROEN 5. EXPERIMENT WITH NEW TECHNOLOGIES Rapidly evolving Android landscape Need to experiment rapidly Cost of wrong technology choice Avoid technology lock-in
29. @MOLSJEROEN Source: https://blog.daftcode.pl/hype-driven-development-3469fc2e9b22
30. @MOLSJEROEN 5. EXPERIMENT WITH NEW TECHNOLOGIES APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
31. @MOLSJEROEN 6. SCALING Large teams cause new issues • Merge conflicts • Dependencies • Code ownership
32. @MOLSJEROEN 6. SCALING: DEVELOP IN PARALLEL Team A Team B APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
33. @MOLSJEROEN 6. SCALING: DEVELOP IN PARALLEL Team A Team B APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
34. @MOLSJEROEN 6. SCALING: OUTSOURCE Team A External company APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
35. @MOLSJEROEN 7. IMPROVE LEGACY CODE
36. @MOLSJEROEN Aggressive High impact Lot of work Not value focussed Risky launch Exciting Less risky Gradual Slow Tedious Continuous releases Unsatisfying REWRITE REFACTOR V S
37. @MOLSJEROEN Aggressive High impact Lot of work Not value focussed Risky launch Exciting Less risky Gradual Slow Tedious Continuous releases Unsatisfying REWRITE REFACTOR V S
38. @MOLSJEROEN 7. IMPROVE LEGACY CODE: REWRITE, REFACTOR OR ACCEPT APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
39. @MOLSJEROEN 7. IMPROVE LEGACY CODE: REWRITE, REFACTOR OR ACCEPT APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
40. @MOLSJEROEN 7. IMPROVE LEGACY CODE Able to rewrite parts of code base Keep ability to release Gradually roll out possible Faster time to market
41. @MOLSJEROEN 8. SIMPLIFY TEST AUTOMATION
42. @MOLSJEROEN 8. SIMPLIFY TEST AUTOMATION
43. @MOLSJEROEN 8. SIMPLIFY TEST AUTOMATION Speeds up tests Simplified test setup Higher test reliability
44. @MOLSJEROEN WHY: RECAP Speed up builds Allow on demand delivery Simplify development Reuse modules across apps Experiment with new technologies Scale development team Improve legacy code Simplify test automation
45. MODULARIZATION ARCHITECTURE
46. YOU HAVE YOUR WAY. I HAVE MY WAY. THE RIGHT WAY, THE CORRECT WAY, AND THE ONLY WAY DOES NOT EXIST. F. Nietzsche
47. @MOLSJEROEN APP STRUCTURE
48. @MOLSJEROEN APP STRUCTURE
49. @MOLSJEROEN APP STRUCTURE
50. @MOLSJEROEN APP STRUCTURE
51. FEATURES ARE A FLOW OF SCREENS
52. @MOLSJEROEN APP WIREFRAME
53. @MOLSJEROEN APP WIREFRAME
54. @MOLSJEROEN APP WIREFRAME
55. APPS CONSIST OF SEVERAL FEATURES
56. @MOLSJEROEN ANDROID APP COMPONENTS ACTIVITY SERVICE BROADCAST RECEIVER CONTENT PROVIDER
57. @MOLSJEROEN ANDROID APP COMPONENTS Full screen UI Reuse across apps Started via explicit or implicit intents ACTIVITY SERVICE BROADCAST RECEIVER CONTENT PROVIDER
58. @MOLSJEROEN IMPLICIT INTENTS
59. ANDROID LINKS MULTIPLE APPS TOGETHER VIA IMPLICIT INTENTS
60. @MOLSJEROEN MODULARIZED ARCHITECTURE APP
61. @MOLSJEROEN MODULARIZED ARCHITECTURE APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
62. @MOLSJEROEN MODULARIZED ARCHITECTURE APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
63. @MOLSJEROEN FEATURE MODULES Full screen, coherent user facing functionality in the app Android library module Single activity with (optional) navigation graph Respond to implicit intents and pass back a result Never depend on other features or app Depend on several library modules APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
64. @MOLSJEROEN LIBRARY MODULES Plumbing that is reused across several or all features Android library, pure Java or pure Kotlin module Never depend on features or app Can (but don’t have to) depend on other libraries APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
65. @MOLSJEROEN APP MODULE Links feature modules together in a useful app Android application module Depends on other features and libraries Orchestrates navigation between features Decides what features are enabled using feature toggles Doesn’t contain much code APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
66. @MOLSJEROEN ADVANTAGES Application structure Navigation Testing Scaling Feature flagging Experiment with new technology
67. @MOLSJEROEN APPLICATION STRUCTURE
68. @MOLSJEROEN DASHBOARD FEATURE
69. @MOLSJEROEN DASHBOARD ACTIVITY
70. @MOLSJEROEN LOGIN FEATURE
71. @MOLSJEROEN SHARING FEATURE
72. @MOLSJEROEN NAVIGATION Split navigation in smaller parts • Within a feature -> handled by the feature • Between features -> handled by the app module APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6
73. @MOLSJEROEN NAVIGATION: IN FEATURE Android Navigation components • Visualize navigation flow • Find back screens • Easy code browsing
74. @MOLSJEROEN NAVIGATION: IN FEATURE
75. @MOLSJEROEN <fragment xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/nav_host_fragment" android:name="androidx.navigation.fragment.NavHostFragment" android:layout_width="match_parent" android:layout_height="match_parent" app:defaultNavHost="true" app:navGraph="@navigation/login_graph"/> NAVIGATION: IN FEATURE
76. @MOLSJEROEN <fragment xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/nav_host_fragment" android:name="androidx.navigation.fragment.NavHostFragment" android:layout_width="match_parent" android:layout_height="match_parent" app:defaultNavHost="true" app:navGraph="@navigation/login_graph"/> NAVIGATION: IN FEATURE
77. @MOLSJEROEN <navigation android:id="@+id/login_graph" app:startDestination="@id/welcomeFragment"> <fragment android:id="@+id/welcomeFragment" android:name="modularization.features.login.WelcomeFragment" /> <fragment android:id="@+id/loginFragment" android:name="modularization.features.login.LoginFragment" /> <fragment android:id="@+id/avatarFragment" android:name="modularization.features.login.AvatarFragment"/> </navigation> NAVIGATION: IN FEATURE
78. @MOLSJEROEN <navigation android:id="@+id/login_graph" app:startDestination="@id/welcomeFragment"> <fragment android:id="@+id/welcomeFragment" android:name="modularization.features.login.WelcomeFragment" /> <fragment android:id="@+id/loginFragment" android:name="modularization.features.login.LoginFragment" /> <fragment android:id="@+id/avatarFragment" android:name="modularization.features.login.AvatarFragment"/> </navigation> NAVIGATION: IN FEATURE
79. @MOLSJEROEN <navigation android:id="@+id/login_graph" app:startDestination="@id/welcomeFragment"> <fragment android:id="@+id/welcomeFragment" android:name="modularization.features.login.WelcomeFragment" /> <fragment android:id="@+id/loginFragment" android:name="modularization.features.login.LoginFragment" /> <fragment android:id="@+id/avatarFragment" android:name="modularization.features.login.AvatarFragment"/> </navigation> NAVIGATION: IN FEATURE
80. @MOLSJEROEN <navigation //... <fragment android:id="@+id/welcomeFragment" android:name="modularization.features.login.WelcomeFragment" > <action android:id="@+id/action_welcomeFragment_to_loginFragment" app:destination="@id/loginFragment" /> </fragment> <fragment android:id="@+id/loginFragment" /> <fragment android:id="@+id/avatarFragment" /> </navigation> NAVIGATION: IN FEATURE
81. @MOLSJEROEN <navigation //... <fragment android:id="@+id/welcomeFragment" android:name="modularization.features.login.WelcomeFragment" > <action android:id="@+id/action_welcomeFragment_to_loginFragment" app:destination="@id/loginFragment" /> </fragment> <fragment android:id="@+id/loginFragment" /> <fragment android:id="@+id/avatarFragment" /> </navigation> NAVIGATION: IN FEATURE
82. @MOLSJEROEN findNavController().navigate(R.id.action_welcomeFragment_to_loginFragment) NAVIGATION: IN FEATURE
83. @MOLSJEROEN NAVIGATION: IN FEATURE
84. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES startActivity(Intent(activity, DashboardActivity::class.java))
85. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES startActivity(Intent("action.dashboard.open"))
86. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="modularization.dashboard"> <application android:theme="@style/AppTheme" > <activity android:name=".DashboardActivity"> <intent-filter> <action android:name="action.dashboard.open"/> <category android:name="android.intent.category.DEFAULT" /> </intent-filter> </activity> </application> </manifest>
87. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="modularization.dashboard"> <application android:theme="@style/AppTheme" > <activity android:name=".DashboardActivity"> <intent-filter> <action android:name="action.dashboard.open"/> <category android:name="android.intent.category.DEFAULT" /> </intent-filter> </activity> </application> </manifest>
88. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES String duplication of action In depth knowledge of intent creation Other apps could also handle action
89. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 ACTIONS LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
90. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openLoginIntent() = Intent("action.login.open") fun openDashboardIntent() = Intent("action.dashboard.open") fun openSharingIntent() = Intent("action.sharing.open") } activity.startActivity(Actions.openDashboardIntent())
91. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openLoginIntent() = Intent("action.login.open") fun openDashboardIntent() = Intent("action.dashboard.open") fun openSharingIntent() = Intent("action.sharing.open") } activity.startActivity(Actions.openDashboardIntent())
92. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openDashboardIntent(userId: String) = Intent(context, "action.dashboard.open") .putExtra(EXTRA_USER, UserArgs(userId)) } activity.startActivity(Actions.openDashboardIntent("userId"))
93. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openDashboardIntent(userId: String) = Intent(context, "action.dashboard.open") .putExtra(EXTRA_USER, UserArgs(userId)) } activity.startActivity(Actions.openDashboardIntent("userId"))
94. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES
95. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openLoginIntent(context: Context) = internalIntent(context, "action.login.open") private fun internalIntent(context: Context, action: String) = Intent(action).setPackage(context.packageName) }
96. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES object Actions { fun openLoginIntent(context: Context) = internalIntent(context, "action.login.open") private fun internalIntent(context: Context, action: String) = Intent(action).setPackage(context.packageName) }
97. @MOLSJEROEN NAVIGATION: BETWEEN FEATURES Implicit intents Actions module Abstract away feature parameters Restrict to current package
98. @MOLSJEROEN TESTING UNIT INTEGRATION E2E
99. @MOLSJEROEN TESTING APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
100. @MOLSJEROEN FEATURE TESTING class LoginFlowTest { @Rule @JvmField var mActivityTestRule = ActivityTestRule(LoginActivity::class.java) @Test fun loginFlowTest() { onView(withId(R.id.button_login_start)).perform(click()) onView(withId(R.id.button_login_signin)).perform(click()) onView(withId(R.id.button_login_toapp)).check(matches(isDisplayed())) } }
101. @MOLSJEROEN FEATURE TESTING class LoginFlowTest { @Rule @JvmField var mActivityTestRule = ActivityTestRule(LoginActivity::class.java) @Test fun loginFlowTest() { onView(withId(R.id.button_login_start)).perform(click()) onView(withId(R.id.button_login_signin)).perform(click()) onView(withId(R.id.button_login_toapp)).check(matches(isDisplayed())) } }
102. @MOLSJEROEN FEATURE TESTING class LoginFlowTest { @Rule @JvmField var mActivityTestRule = ActivityTestRule(LoginActivity::class.java) @Test fun loginFlowTest() { onView(withId(R.id.button_login_start)).perform(click()) onView(withId(R.id.button_login_signin)).perform(click()) onView(withId(R.id.button_login_toapp)).check(matches(isDisplayed())) } }
103. @MOLSJEROEN APP FLOW TESTING class AppFlowTest { @Rule @JvmField var mActivityTestRule = ActivityTestRule(MainActivity::class.java) @Test fun test_criticalUserFlow_throughoutEntireApp() { onView(withId(modularization.login.R.id.button_login_start)).perform(click()) onView(withId(modularization.login.R.id.button_login_signin)).perform(click()) onView(withId(modularization.login.R.id.button_login_toapp)).perform(click()) onView(withId(R.id.action_albums)).perform(click()) onView(withId(R.id.action_sharing)).perform(click()) onView(withId(R.id.button_social_facebook)).perform(click()) onView(withId(R.id.recyclerView_sharing_contacts)).check(matches(isDisplayed())) } }
104. @MOLSJEROEN SCALING: TEAMS Team A Team B APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
105. @MOLSJEROEN APP 1 FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 1 LIBRARY 2 APP 2 FEATURE X FEATURE X SCALING: APPS
106. @MOLSJEROEN SCALING: SDKS APP EXPOSED FEATURE WITH INTENT FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 AWESOME GITHUB LIBRARY LIB 1 SDK LIBRARY 3
107. @MOLSJEROEN SCALING: TECHNOLOGY APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
108. @MOLSJEROEN IMPROVE LEGACY APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
109. @MOLSJEROEN IMPROVE LEGACY: REWRITE FEATURE APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3
110. @MOLSJEROEN IMPROVE LEGACY: REWRITE FEATURE APP FEATURE 1 FEATURE 2 FEATURE 3 FEATURE 4 FEATURE 5 FEATURE 6 LIBRARY 4 LIBRARY 4 LIB 1 LIBRARY 2 LIBRARY 3 FEATURE 5*
111. @MOLSJEROEN IMPROVE LEGACY: FEATURE FLAGS object Actions { fun openLoginIntent() = if (FeatureFlag.loginRewrite) { Intent("action.login2.open") } else { Intent("action.login.open") } }
112. @MOLSJEROEN IMPROVE LEGACY: FEATURE FLAGS object Actions { fun openLoginIntent() = if (FeatureFlag.loginRewrite) { Intent("action.login2.open") } else { Intent("action.login.open") } }
113. @MOLSJEROEN IMPROVE LEGACY: ROLL OUT
114. @MOLSJEROEN
115. @MOLSJEROEN ARCHITECTURE: RECAP Easy code navigation Simple in-feature and across feature navigation Better test automation Enables scaling Able to experiment with new technologies Staged rollout of rewritten features
116. HOW TO APPROACH
117. @MOLSJEROEN APP FEATURE FEATURE FEATURE FUTURE. FEATURE FUTURE FEATURE FUTURE FEATURE OLD APP LIB LIBRARY FUTURE LIBRARY APP FEATURE FEATURE FEATURE FUTURE FEATURE FUTURE FEATURE FUTURE FEATURE LIB 1 LIB FUTURE LIBRARY LIBRARY CHOOSE YOUR SIDE
118. @MOLSJEROEN PULL CODE UP APP FEATURE FEATURE FEATURE FUTURE FEATURE FUTURE FEATURE FUTURE FEATURE OLD APP LIB LIBRARY FUTURE LIBRARY Pull modules up
119. @MOLSJEROEN PULL CODE UP Conceptually very simple Extract features without dependency issues Huge upfront change Encourages gradual modularization Incompatible with Butterknife: change to R2.id.*** Features need to be extracted before libraries
120. @MOLSJEROEN PUSH CODE DOWN APP FEATURE FEATURE FEATURE FUTURE FEATURE FUTURE FEATURE FUTURE FEATURE LIB 1 LIB FUTURE LIBRARY LIBRARY Push modules down
121. @MOLSJEROEN PUSH CODE DOWN Initially a lot harder Extract libraries without dependency issues No big upfront change Forces aggressive modularisation Better grip on modularisation process Bottom up code clean up
122. @MOLSJEROEN APP FEATURE FEATURE FEATURE FUTURE. FEATURE FUTURE FEATURE FUTURE FEATURE OLD APP LIB LIBRARY FUTURE LIBRARY APP FEATURE FEATURE FEATURE FUTURE FEATURE FUTURE FEATURE FUTURE FEATURE LIB 1 LIB FUTURE LIBRARY LIBRARY CHOOSE YOUR SIDE
123. @MOLSJEROEN APP FEATURE FEATURE FEATURE FUTURE. FEATURE FUTURE FEATURE FUTURE FEATURE OLD APP LIB LIBRARY FUTURE LIBRARY APP FEATURE FEATURE FEATURE FUTURE FEATURE FUTURE FEATURE FUTURE FEATURE LIB 1 LIB FUTURE LIBRARY LIBRARY CHOOSE YOUR SIDE
124. @MOLSJEROEN CONSIDERATIONS Make a big initial push Aggressively restrict visibility Combine with general code improvements Postpone/avoid problems • Cut dependencies using abstractions • Deprecate and rewrite • Clean up internals later
125. WHEN PLANNING IS LONG THEN IT’S WRONG, IF IT’S TIGHT THEN IT’S RIGHT Elon musk
126. LESSONS LEARNED
127. @MOLSJEROEN CONFIGURE MODULES Adding a new module must be easy Maintaining module configurations must be easy
128. @MOLSJEROEN CONFIGURE MODULES subprojects { afterEvaluate { project -> if (project.hasProperty('android')) { android { buildToolsVersion Config.buildTools compileSdkVersion Config.compileSdk defaultConfig { minSdkVersion Config.minSdk targetSdkVersion Config.targetSdk } compileOptions { sourceCompatibility Config.javaVersion targetCompatibility Config.javaVersion } } } } }
129. @MOLSJEROEN CONFIGURE MODULES subprojects { afterEvaluate { project -> if (project.hasProperty('android')) { android { buildToolsVersion Config.buildTools compileSdkVersion Config.compileSdk defaultConfig { minSdkVersion Config.minSdk targetSdkVersion Config.targetSdk } compileOptions { sourceCompatibility Config.javaVersion targetCompatibility Config.javaVersion } } } } }
130. @MOLSJEROEN CONFIGURE MODULES subprojects { afterEvaluate { project -> if (project.hasProperty('android')) { android { buildToolsVersion Config.buildTools compileSdkVersion Config.compileSdk defaultConfig { minSdkVersion Config.minSdk targetSdkVersion Config.targetSdk } compileOptions { sourceCompatibility Config.javaVersion targetCompatibility Config.javaVersion } } } } }
131. @MOLSJEROEN CONFIGURE MODULES apply plugin: 'com.android.library' apply plugin: 'kotlin-android-extensions' apply plugin: 'kotlin-android' dependencies { implementation project(':libraries:ui-components') implementation project(':libraries:actions') implementation Deps.androidx_material implementation Deps.androidx_constraintlayout implementation Deps.androidx_navigation_fragment implementation Deps.androidx_navigation_ui testImplementation Deps.testlib_junit androidTestImplementation Deps.testandroidx_runner androidTestImplementation Deps.testandroidx_rules androidTestImplementation Deps.testandroidx_espressocore }
132. @MOLSJEROEN CONFIGURE MODULES
133. @MOLSJEROEN MODULE GRAPH apply from: 'https://raw.githubusercontent.com/JakeWharton/SdkSearch/master/ gradle/projectDependencyGraph.gradle' ./gradlew projectDependencyGraph
134. @MOLSJEROEN MODULE GRAPH
135. @MOLSJEROEN ORGANIZE SETTINGS.GRADLE include ':app', ':features:login', ':features:dashboard', ':features:sharing', ':libraries:ui- components', ':libraries:actions'
136. @MOLSJEROEN ORGANIZE SETTINGS.GRADLE include ':app' include ':features:login' include ':features:dashboard' include ':features:sharing' include ':libraries:ui-components' include ':libraries:actions'
137. @MOLSJEROEN ORGANIZE SETTINGS.GRADLE include ':app' include ':features:login' include ':features:dashboard' include ':features:sharing' include ':libraries:ui-components' include ':libraries:actions'
138. @MOLSJEROEN MODULE INTERNALS
139. @MOLSJEROEN MODULE INTERNALS - ORGANIZATION
140. @MOLSJEROEN MODULE INTERNALS - ORGANIZATION
141. @MOLSJEROEN MODULE INTERNALS - PACKAGE NAME features: [project-name].features.[feature-name]
 e.g. modularization.features.login libraries: [project-name].libraries.[library-name]
 e.g. modularization.libraries.actions
142. @MOLSJEROEN MODULE INTERNALS - PACKAGE NAME import android.content.Intent import android.os.Bundle import androidx.appcompat.app.AppCompatActivity import modularization.features.login.LoginActivity import modularization.features.sharing.SharingActivity import modularization.features.dashboard.DashboardActivity import modularization.libraries.actions.Actions import modularization.libraries.uicomponents.RoundedButton
143. @MOLSJEROEN LAYOUT PREVIEWS
144. @MOLSJEROEN LAYOUT PREVIEWS
145. @MOLSJEROEN LAYOUT PREVIEWS <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="modularization.features.dashboard"> <application android:theme="@style/AppTheme"> <activity android:name=".DashboardActivity" /> </application> </manifest>
146. @MOLSJEROEN LAYOUT PREVIEWS <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="modularization.features.dashboard"> <application android:theme="@style/AppTheme"> <activity android:name=".DashboardActivity" /> </application> </manifest>
147. @MOLSJEROEN LAYOUT PREVIEWS
148. @MOLSJEROEN DEPENDENCY MANAGEMENT object Config { val minSdk = 23 val javaVersion = JavaVersion.VERSION_1_8 val buildTools = "28.0.3" } object Versions { val androidx_core = "1.0.1" val androidx_nav = "2.0.0" ... } object Deps { val androidx_core = "androidx.core:core-ktx:${Versions.androidx_core}" val androidx_nav_fragment = "androidx.navigation:navigation-fragment-ktx:${Versions.androidx_nav}" val androidx_nav_ui = “androidx.navigation:navigation-ui-ktx:${Versions.androidx_nav}" ... }
149. @MOLSJEROEN CONFIGURE MODULES apply plugin: 'com.android.library' apply plugin: 'kotlin-android-extensions' apply plugin: 'kotlin-android' dependencies { implementation project(':libraries:ui-components') implementation project(':libraries:actions') implementation Deps.androidx_material implementation Deps.androidx_constraintlayout implementation Deps.androidx_navigation_fragment implementation Deps.androidx_navigation_ui testImplementation Deps.testlib_junit androidTestImplementation Deps.testandroidx_runner androidTestImplementation Deps.testandroidx_rules androidTestImplementation Deps.testandroidx_espressocore }
150. @MOLSJEROEN DEPENDENCY MANAGEMENT ./gradlew dependencyUpdates
151. @MOLSJEROEN SPEED UP BUILDS dependencies { // Avoid doing this api project(':libraries:ui-components') // Do this instead implementation project(':libraries:ui-components') }
152. @MOLSJEROEN API VS IMPLEMENTATION DEPENDENCY APP
153. @MOLSJEROEN API DEPENDENCY APP
154. @MOLSJEROEN API DEPENDENCY APP
155. @MOLSJEROEN API DEPENDENCY APP
156. @MOLSJEROEN IMPLEMENTATION DEPENDENCY APP
157. WRAP UP
158. THERE ARE NO BIG PROBLEMS, THERE ARE JUST A LOT OF LITTLE PROBLEMS. Henry Ford
159. @MOLSJEROEN MODULARIZATION HAS TONS OF BENEFITS APP FEATURES LIBRARIES NAVIGATION WITHIN AND BETWEEN FEATURES PUSH CODE DOWN SIMPLIFY ADDING MODULES
160. @MOLSJEROEN
161. @MOLSJEROEN HTTPS://JEROENMOLS.COM/BLOG
162. @MOLSJEROEN REFERENCES Blog posts: 1. http://bit.ly/modularization_why 2. http://bit.ly/modularization_architecture 3. http://bit.ly/modularization_example 4. http://bit.ly/modularization_how 5. http://bit.ly/modularization_lessons http://bit.ly/modularization_code
163. @MOLSJEROEN IMAGE CREDITS Welcome image by Clement127 https://flic.kr/p/n9ctTn Official Android documentation https://d.android.com Font awesome https://fontawesome.com/
164. MOLSJEROEN