An introduction to using Gradle with Android The accompanying example code is on github: https://github.com/ckurtm/Gradle101

1. Building with Gradle 101
Kurt Mbanje : DStv Digital Media
+KurtMbanje
@ckurtm

2. What is Gradle?

3. Why Gradle?

4. Background: Android Build Process

5. Why Gradle?
• Declarative vs Imperative
• Flexibility & Customization
• “Convention over Configuration” , well
…convention is good but so is flexibility

6. Declarative vs Imperative
• Imperative : script how to do something, and as a
result what you want to happen will happen
• Declarative: script what you would like to happen,
and let the tool figure out how to do it

7. Declarative vs Imperative
• Imperative : script how to do something, and as a
result what you want to happen will happen
• Declarative: script what you would like to happen,
and let the tool figure out how to do it

8. Flexibility & Customization
• Supports Android’s diverse ecosystem, e.g. ABI,
density , API level etc.
• Split apks for Play Store
• Still allows you to write plugins and tasks

9. Flexibility & Customization
• Supports Android’s diverse ecosystem, e.g. ABI,
density , API level etc.
• Split apks for Play Store
• Still allows you to write plugins and tasks

10. Flexibility & Customization
• Supports Android’s diverse ecosystem, e.g. ABI,
density , API level etc.
• Split apks for Play Store
• Still allows you to write plugins and tasks

11. Convention over Configuration ++

12. Android Gradle Concepts
• Build Types - how the application is packaged, and how the
compiler is called (mostly)
Debug vs Release (vs. <other>)
• Product Flavors – mostly has to do with features
paid vs. free
abi packaging
• Variants = Build Types + Flavors
freeDebug , paidRelease , paidDebug , freeRelease

13. Android Gradle Concepts
• Build Types - how the application is packaged, and how the
compiler is called (mostly)
Debug vs Release (vs. <other>)
• Product Flavors – mostly has to do with features
paid vs. free
abi packaging
• Variants = Build Types + Flavors
freeDebug , paidRelease , paidDebug , freeRelease

14. Android Gradle Concepts
• Build Types - how the application is packaged, and how the
compiler is called (mostly)
Debug vs Release (vs. <other>)
• Product Flavors – mostly has to do with features
paid vs. free
abi packaging
• Variants = Build Types + Flavors
freeDebug , paidRelease , paidDebug , freeRelease

15. Sample Android build script: build.gradle
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:1.3.0'
}
}
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.2"
defaultConfig {
applicationId "com.example.test"
minSdkVersion 15
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:23.1.0'
}

16. Build Script: Repositories & Android Plugin
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:1.3.0'
}
}

17. Android Plugin
apply plugin: 'com.android.application'

18. Compile SDK & Tools Version
android {
compileSdkVersion 23
buildToolsVersion "23.0.2"

19. Example: Build Types
buildTypes {
release {
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
debug {
minifyEnabled true
applicationIdSuffix '.debug'
versionNameSuffix '.debug'
}
}

20. Default Config
defaultConfig {
applicationId "com.example.test"
minSdkVersion 15
targetSdkVersion 23
versionCode 1
versionName "1.0"
}

21. Flavors

22. Build Variants
• Variants = Build Types + Flavors
freeDebug , paidRelease , paidDebug , freeRelease
Debug Release
Free freeDebug freeRelease
Paid paidDebug paidRelease
• Flavor Groups /Dimensions
adds another 3rd matrix to the mix… or 4th

23. Dependencies
• Local file
Jar or aar file
• Remote / Local repositories
JCenter, maven , custom etc.

24. Tip 1: View app dependencies
./gradlew :app:dependencies
./gradlew :app:androidDependencies

25. Tip 2: Use Gradle wrapper!
./gradle wrapper --gradle-version 2.0
task wrapper(type: Wrapper) {
gradleVersion = '2.0'
}

26. Tip 3: Gradle GUI
./gradle --gui

27. Tip 4: Different Icon per BuildType

28. Tip 5: BuildConfig.java
public final class BuildConfig {
public static final boolean DEBUG = Boolean.parseBoolean("true");
public static final String APPLICATION_ID = "com.peirr.test.debug";
public static final String BUILD_TYPE = "debug";
public static final String FLAVOR = "";
public static final int VERSION_CODE = 1;
public static final String VERSION_NAME = "1.0.debug";
}

29. Thanks
https://docs.gradle.org/current/userguide/gradle_wrapper.html
https://github.com/ckurtm/Gradle101
http://tools.android.com/tech-docs/new-build-system