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Understanding your
builds
twitter.com
github.com
@charlesmuchene
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Understanding your
builds
twitter.com
github.com
@charlesmuchene
• Introduction
• AS & Gradle
• Groovy basics
• Android Build Process
• Sample tasks
Agenda
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@SafeBoda | @SafeBoda_Kenya
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Gradle
• Highly customisable - custom build configs, plugins etc
• Fast - employs caching, incremental, *parallel builds etc
• Powerful - supports popular languages and technologies
open-source build and automation tool
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AS & Gradle
AS delegates the entire build process to Gradle
Building Android apps
ADB
:assemble artifact
Install using
adb
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The basics
Gradle scripts are written using *Groovy (and now Kotlin)
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Groovy
def age = 23
String name = "SenseiDev"
def someFunction(a, b) {
// Does awesome stuff
}
class Session {
String title = "Understanding your builds"
def printTitle() {
println "Session title: $title"
}
}
variables, functions, classes
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Groovy cntd.
def event = “Droidcon"
def country = "KE"
def posterPrinter = {
println "Attending ${event}${country}"
}
posterPrinter()
def adder = {a, b -> a + b}
def result = adder 7, 3
println result
closures
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Groovy cntd.
def builderTask(Closure configClosure) {
// All good stuff using configClosure
}
def closureImpl = {
// Does awesome work
}
builderTask(closureImpl)
closures
Definition:
Invocation:
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Groovy cntd.
def builderTask(Closure configClosure) {
// All good stuff using configClosure
}
builderTask({
// Does awesome work
})
closures
Definition:
Invocation:
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Groovy cntd.
def builderTask(Closure configClosure) {
// All good stuff using configClosure
}
builderTask() {
// Does awesome work
}
closures
Definition:
Invocation:
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Groovy cntd.
def builderTask(Closure configClosure) {
// All good stuff using configClosure
}
builderTask {
// Does awesome work
}
closures
Definition:
Invocation:
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Groovy cntd.
class AppBuilder {
String platform = "Unknown"
def build() {
println "Building for $platform..."
}
}
def appBuilder = new AppBuilder()
def buildApp = {
platform = "Android"
build()
}
buildApp.delegate = appBuilder
buildApp()
delegates
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Gradle-Wrapper
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Gradle-Wrapper
Micro-library for downloading distribution
List dist. url, version and other options
Gradle executable for *nix systems
Gradle executable for Windows systems
~150Kb
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Tasks
Self-contained unit of work
task [(configs.)] {
// actions
}
gradle
Executing a task:
Task syntax:
gradle tasks
Show all tasks:
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• Initialization Phase
Configure environment (init.gradle, gradle.properties)
Find projects and build scripts (settings.gradle)
• Configuration Phase
Evaluate all build scripts
Build task execution graph
• Execution Phase
Execute tasks
Gradle Build lifecycle
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Android Build Process
android.com
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App module structure
• settings.gradle - what modules should be
included
• build.gradle (project-level) - configurations for
all modules in the project e.g.
• build.gradle (module-level) - configures build
settings for the module
• *gradle.properties - project-wide Gradle
settings e.g. caching, daemon max heap size
etc
• **local.properties - local environment properties
for the build system e.g. local sdk, ndk paths
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settings.gradle
specifies modules to be included when building your app
include ‘:app’
include ‘:app’, ‘:common’
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build.gradle (project-level)
configurations for all modules in project
buildscript {
repositories {
google()
jcenter()
}
dependencies {
classpath ‘com.android.tools.build:gradle:3.2.0’
classpath ‘org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.71’
}
}
allprojects {
repositories {
google()
jcenter()
}
}
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build.gradle (module-level)
configurations for a module
apply plugin: ‘com.android.application’
apply plugin: ‘kotlin-android’
apply plugin: ‘kotlin-android-extensions’
apply plugin: ‘kotlin-kapt’
android {
... // additional configurations
}
dependencies {
... // dependencies list
}
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build.gradle (module-level)
configurations for a module (contd.)
android {
compileSdkVersion 28
defaultConfig {
versionCode 87
minSdkVersion 21
targetSdkVersion 28
versionName "3.2.10-alpha.1"
applicationId “com.charlesmuchene.app"
buildConfigField "String", “INSTABUG_TOKEN", “ab12cd34"
... // additional configurations
}
}
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build.gradle (module-level)
configurations for a module (contd.)
android {
defaultConfig {
... // other configurations
buildTypes {
beta {
minifyEnabled true
shrinkResources true
proguardFiles getDefaultProguardFile(‘proguard-android.txt'), 'proguard-rules.pro'
}
release {
minifyEnabled true
shrinkResources true
buildConfigField "String", "INSTABUG_TOKEN", ‘"zz98yy76"'
proguardFiles getDefaultProguardFile(‘proguard-android.txt'), 'proguard-rules.pro'
}
}
}
}
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Sample task
task clean(type: Delete) {
delete rootProject.buildDir
}
remove build dir.
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Sample task
task exportArtifacts(type: Copy) {
description "Copy artifacts for distribution to project root”
group "Installer Automator”
dependsOn assemble, assembleAndroidTest
from("$buildDir/outputs/apk/debug") {
exclude "*.json"
rename "(.*)\\.apk", "install-checker.apk"
}
from("$buildDir/outputs/apk/androidTest/debug") {
exclude "*.json"
rename "(.*)\\.apk", "install-automator.apk"
}
into("$rootDir/artifacts")
}
export artifacts to a custom directory
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Sample configuration
read signing configs from excluded properties file
def keystorePropertiesFile = rootProject.file("keystore.properties")
if (keystorePropertiesFile.exists()) {
def key = new Properties()
key.load(new FileInputStream(keystorePropertiesFile))
android {
signingConfigs {
debug {
storeFile rootProject.file('debug.keystore')
}
config {
keyAlias key['alias']
keyPassword key['key']
storePassword key['store']
storeFile file(key['file'])
}
}
..
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References
• http://groovy-lang.org
• https://docs.gradle.org/current/dsl/
• https://developer.android.com/studio/build/
• https://google.github.io/android-gradle-dsl/current/
Happy building