Android Development with Gradle shakalaca @ Google I/O Extended Taipei http://goo.gl/QTcTlP 

Hello ! I’m Shaka • Co-Organizer @ GDG Taipei • Consultant @ SleepNOVA, Inc. • CTO @ SmarTapper Co., Ltd. http:/ /about.me/shakalaca 

What is gradle ? Gradle is build automation evolved. Gradle can automate the building, testing, publishing, deployment and more of software packages or other types of projects such as generated static websites, generated documentation or indeed anything else. ! Gradle combines the power and flexibility of Ant with the dependency management and conventions of Maven into a more effective way to build. Powered by a Groovy DSL and packed with innovation, Gradle provides a declarative way to describe all kinds of builds through sensible defaults. Gradle is quickly becoming the build system of choice for many open source projects, leading edge enterprises and legacy automation challenges. - http:/ /www.gradle.org/ 

.. short version An open source build system that combines the power of Ant & Maven but easy to use 

Why (google wants to change the build system to) gradle ? • Simplify and unify project dependency management in IDE & CLI • Think about Eclipse & ant (ci server) • Android Studio is coming ! BETA 

Should I use it ? • For small project • Easy to convert • For large project • Worth trying if it can simplify the configurations (dependency) • For project with variants • Time for better management tool 

How gradle works ? • Lifecycle • Initialisation • Configuration • Execution • Build scripts • build.gradle • settings.gradle (optional) • gradle.properties (optional) http://www.gradle.org/docs/current/userguide/build_lifecycle.html 

Command • gradle • tasks • clean • assemble • assembleRelease • assembleDebug • aR / asD • check • build (assemble + check) 

Android integration • gradle android plugin • http:/ /tools.android.com/tech-docs/new- build-system/ • output • /build/output/apk/ 

Setup • Install gradle • http:/ /www.gradle.org/docs/current/ userguide/installation.html • Install add-on for Android • SDK Manager 

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Project structure • / • gradle wrapper • configuration files • *.gradle / *.properties • app • library • lib1, lib2 … 

gradle wrapper • Helper for project building • Compile your code anywhere • Easy to install • Just run “gradle wrapper” under project directory 

gradle wrapper 

/ gradle.properties • Gradle specific settings • org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError - Dfile.encoding=UTF-8 • org.gradle.parallel=true • Project wide variables • var_name_you_want_to_use=value • use with project.var_name_you_want_to_use http://www.gradle.org/docs/current/userguide/build_environment.html 

/ settings.gradle 

/build.gradle 

/app/ build.gradle 

/app/ build.gradle 

/app/ build.gradle 

Android packages ! • com.android.support:support-v4:19.1.0 • com.android.support:support-v13:19.1.0 • com.android.support:appcompat-v7:19.1.0 • com.android.support:gridlayout-v7:19.1.0 • com.android.support:mediarouter-v7:19.1.0 • com.google.android.gms:play-services:4.4.52 • com.android.support:support-annotations:19.1.0 

/app/ build.gradle 

defaultConfig • versionCode • versionName • minSdkVersion • targetSdkVersion • applicationId (old: packageName) • signingConfig • proguardFile • proguardFiles • testApplicationId (old: testPackageName) • testInstrumentationR unner 

/app/ build.gradle 

/app/ build.gradle 

Build types • default 2 types: debug & release • for debugging & signing • custom type • custom.initWith(buildTypes.debug) 

Build types • debuggable • jniDebugBuild • renderscriptDebugBuild • renderscriptOptimLevel • applicationIdSuffix (old: packageNameSuffix) • versionNameSuffix • signingConfig • zipAlign • runProguard • proguardFile • proguardFiles 

/app/ build.gradle 

/app/ build.gradle 

lint options • change severity • options: http:/ /tools.android.com/tips/lint-checks • ex: fatal 'NewApi', ‘InlineApi' • error/warning/ignore • reports • textReport/xmlReport/htmlReport (boolean) • textOutput/xmlOutput/htmlOutput (file) http:/ /tools.android.com/tech-docs/new-build-system/user-guide#TOC-Lint-support 

For the brave… • abortOnError true • checkAllWarnings true • warningsAsErrors true 

Other options • packagingOptions
 { exclude ‘META-INF/LICENSE.txt' 
 exclude ‘META-INF/NOTICE.txt’ } • aaptOptions
 { useAaptPngCruncher = true } • compileOptions
 { sourceCompatibility JavaVersion.VERSION_1_7
 targetCompatibility JavaVersion.VERSION_1_7 } 

/libproject/ build.gradle 

/libproject/ build.gradle 

Happy building • Write build.gradle & settings.gradle in project root directory • Write build.gradle in app / library project directory • Build: gradle assemble • /build/outputs/apk/ 

Build variant • Creating different versions of same application • free/paid • multi-apk • Build Variant = Build Type + Product Flavor 

Product flavor • Defines a customised version of application build by the project • Free / Paid • Amazon / Play Store / blah store • Same type as defaultConfig 

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Build • gradle assemblePaid • gradle aPD / gradle aPR • gradle assembleFree • gradle aFD / gradle aFR 

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All samples are here http:/ /github.com/shakalaca/ learning_gradle_android 

References • Documentation • http:/ /tools.android.com/tech-docs/new-build-system (Guide / Samples) • http:/ /www.gradle.org/documentation • Forums • https:/ /plus.google.com/u/0/communities/114791428968349268860 • https:/ /groups.google.com/forum/#!forum/adt-dev • http:/ /stackoverflow.com/questions/tagged/gradle • Tool • http:/ /gradleplease.appspot.com/ • [email protected]:nenick/android-gradle-template.git 

Or follow me @ • G+ • http:/ /google.com/profiles/shakalaca • Blog • http:/ /23pin.logdown.com • Taipei GDG (G+ Community) • https:/ /plus.google.com/communities/ 100566773212437391191 

Q & A 

Maven repository 

Why & How ? • Time is money • Use aar instead of re-compiling everything • aar: Binary distribution of an Android Library Project • http:/ /tools.android.com/tech-docs/new- build-system/aar-format 

Project layout 

root-build.gradle 

library/build.gradle 

project/build.gradle • archivesBaseName • version 

app/build.gradle 

How • deploy library • ./gradlew deploy • use local repository • ./gradlew as -PuseRepo