Gradle Dependencies The Smart Way
Manage your dependencies like a boss
We will cover the following topics:
- defining variables (version codes)
- custom compile configurations
- dependencies.gradle in separate file
build.gradle
I bet your module level build.gradle file looks like this:
apply plugin: 'com.android.application'
apply plugin: 'me.tatarka.retrolambda'
apply plugin: 'realm-android'
android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
applicationId "com.rozkmin.demoapp"
minSdkVersion 19
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
debug {
}
release {
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_8
targetCompatibility JavaVersion.VERSION_1_8
}
productFlavors {
freeFlavor {
applicationId "com.rozkmin.demoappfree"
resValue("string", "app_name", "DemoAppFree")
versionName "1.20.2"
}
premiumFlavor{
applicationId "com.rozkmin.demoapppremium"
resValue("string", "app_name", "DemoAppPremium")
versionName "1.20.2"
}
}
}
dependencies {
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:24.2.1'
compile 'com.android.support:design:24.2.1'
compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.1.0'
compile 'com.squareup.retrofit2:converter-gson:2.1.0'
compile 'com.android.support:support-v4:24.2.1'
testCompile 'junit:junit:4.12'
apt 'com.jakewharton:butterknife-compiler:8.4.0'
}
}
In short words — a lot of ugly dependencies. and sometimes comments what does specific library do.
Forget it. In this post we will create human readable and developer friendly build.gradle for your next app.
Defining variables
First thing we will do to make gradle code cleanear, will be introducing variables.
In module-level build.gradle write: Write
def googlePlayVersion = '1.20.2'
Now we can use it in our build file like that:
productFlavors {
freeFlavor {
applicationId "com.rozkmin.demoappfree"
resValue("string", "app_name", "DemoAppFree")
versionName "$googlePlayVersion"
}
premiumFlavor {
applicationId "com.rozkmin.demoapppremium"
resValue("string", "app_name", "DemoAppPremium")
versionName "$googlePlayVersion"
}
}
Automate naming apks on different flavors and configs:
When you build app for QA team, you usually want to change .apk name:
applicationVariants.all { variant ->
variant.outputs.each { output ->
def outputFile = output.outputFile
def appName = "app-" + "${variant.baseName.replace("-release", "")}" + "_v" + "${variant.versionName}.apk"
output.outputFile = new File(outputFile.parent, appName)
}
}
Keep dependencies in separate file
Now let’s do something more tricky. Create file dependencies.gradle in your project directory:
ext {
def RxJava2Version = '2.1.1'
def RxAndroid2Version = '2.0.1'
def Retrofit2Version = '2.3.0'
def OkHttp3Version = '3.8.0'
rxDependencies = [
rxJava : "io.reactivex.rxjava2:rxjava:${RxJava2Version}",
rxAndroid : "io.reactivex.rxjava2:rxandroid:${RxAndroid2Version}",
]
networkDependencies = [
retrofit : "com.squareup.retrofit2:retrofit:${Retrofit2Version}",
okhttp : "com.squareup.okhttp3:okhttp:${OkHttp3Version}",
converterGson : "com.squareup.retrofit2:converter-gson:${Retrofit2Version}",
adapterRxJava2 : "com.squareup.retrofit2:adapter-rxjava2:${Retrofit2Version}"
]
}
Now in your top-level build.gradle file write apply from: ‘dependencies.gradle’
buildscript {
repositories {
jcenter()
google()
}
dependencies {
classpath 'me.tatarka:gradle-retrolambda:3.2.5'
classpath 'com.android.tools.build:gradle:2.3.3'
classpath "io.realm:realm-gradle-plugin:2.2.0"
}
}
allprojects {
repositories {
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
apply from: 'dependencies.gradle'
Now you can use it in your module level build.gradle file:
dependencies {
//other dependencies
compile networkDependencies.values()
compile rxDependencies.values()
//other dependencies
}
I highly recommend to use these code in all your projects. build.gradle will be much cleaner and easier to maintain. It’s great because you can keep your favourite libraries in one file, store them in some gist and just copy-paste them when creating new project. It also helps you keeping the same versions of libraries in multi-module projects. Much better than commenting and uncommenting specific lines or switching between several module-level build.gradle just to update RxJava version.
Compile configurations
You don’t need jUnit or Mockito in you application code. If you use it, something went very wrong. We have some predefined configurations for test builds:
testCompile unitTestDependencies.values()
androidTestCompile testDependencies.values()
They are available in android starter projects.
Custom configurations
Let’s say you have to build app for development, other for your QA team and build another one to show at demo to your customers. You want to include different version of your modules in app. Based on flavors and build type following compile configs will be generated:
freeFlavorReleaseCompile project(path: ':mylibrary', configuration: 'release')
freeFlavorQaCompile project(path: ':mylibrary', configuration: 'debug')
freeFlavorDebugCompile project(path: ':mylibrary', configuration: 'debug')
Use environmental variables
signingConfigs {
release {
storeFile file("my_secret_key.jks")
keyAlias 'demoapp'
storePassword "${System.env.PW_DA_KEYSTORE}"
keyPassword "${System.env.PW_DA_KEYSTORE}"
}
}
Use it for keeping your developer keys secret. You don’t have to (and probably should not) keep your google play secrets on repo and share across your team. The same applies if you have some other secrets that you want to use only during build.
How do you manage your dependencies? Share some gradle tips and tricks in comments.