Gradle Tutorial for Android: Getting Began – Half 2

In Half 1 of this tutorial, you discovered how one can learn and construct Gradle recordsdata and how one can handle dependencies in a number of methods. On this half, you’ll study barely extra complicated elements of Gradle. By the tip, you’ll be capable to:

1. Signal your releases and have totally different construct varieties.
2. Create Gradle duties and plugins.
3. Create construct flavors for revenue.

Getting Began

Obtain the starter mission by clicking the Obtain Supplies hyperlink on the high or backside of the tutorial. You’ll decide up the place you left off in Half 1.

This a part of the tutorial will give attention to how one can use Kotlin script, because it’s now the popular means of writing Gradle recordsdata. Nevertheless, each little bit of Kotlin script code may have its Groovy equal so you too can study it. If the choice Groovy model doesn’t exist, you possibly can assume that the particular little bit of code you’re taking a look at is equivalent for each instances.

Getting Able to Publish: Working with Product Flavors and Construct Varieties

Within the final article, you completed constructing your app. Now, you’re considering of how to revenue from it :]

One answer is to have a number of variations of your app: a free model and a paid model. Happily, Gradle helps this on the construct degree and means that you can outline the boundaries of various construct varieties. However earlier than you get began, it is advisable to perceive how Gradle means that you can work with totally different app variations.

Introducing Construct Varieties

By default, there are two construct varieties – debug and launch. The one distinction between them is the worth of the debuggable parameter. In different phrases, you should use the debug model to assessment logs and to debug the app, however the launch sort is used to publish your app to the Google Play Retailer. Configure properties to the construct varieties by including the next code within the android block of your module-level construct.gradle.kts file:

buildTypes {
  launch {
  }
  debug {
  }
}

Specify the type-specific settings of your utility within the debug and launch blocks.

Studying About Construct Signing

Some of the necessary configurations of the construct is its signature. With out a signature, you received’t be capable to publish your utility as a result of it’s essential to confirm you as an proprietor of the particular utility. When you don’t have to signal the debug construct – Android Studio does it routinely — the discharge construct needs to be signed by a developer.

When your keystore is prepared, add the code beneath within the android block and above the buildTypes block (the order of declaration issues) of the module-level construct.gradle.kts file:

signingConfigs {
  create("launch") {
    storeFile = file("path to your keystore file")
    storePassword = "your retailer password"
    keyAlias = "your key alias"
    keyPassword = "your key password"
  }	
}

In the event you’re utilizing Groovy, add this code as a substitute:

signingConfigs {
  launch {
    storeFile file("path to your keystore file")
    storePassword "your retailer password"
    keyAlias "your key alias"
    keyPassword "your key password"
  }
}

Within the signingConfigs block, specify your signature information for the construct varieties. Take note of the keystore file path. Specify it with respect to the module listing. In different phrases, when you created a keystore file within the module listing and named it “keystore.jks”, the worth it’s best to specify will probably be equal to the identify of the file.

Replace the buildTypes block to signal your launch construct routinely:

launch {
  signingConfig = signingConfigs.getByName("launch")
}

And the Groovy model:

launch {
  signingConfig signingConfigs.launch
}

Or, when you’re utilizing Groovy:

Then, make sure to preserve keystorePassword.gradle.kts ignored by your model management system. Different methods embody conserving the password in an OS-level surroundings variable, particularly in your distant Steady Integration system, similar to CircleCI.

1. When you’ve printed your app to the Google Play Retailer, subsequent submissions should use the identical keystore file and password, so preserve them protected.
2. Make certain NOT to commit your keystore passwords to a model management system similar to GitHub. You are able to do so by conserving the password in a separate file from construct.gradle.kts, say keystorePassword.gradle.kts in a Signing listing, after which referencing the file from the app module-level construct.gradle.kts by way of:

   apply(from = "../Signing/keystorePassword.gradle.kts")
   

   apply from: "../Signing/keystorePassword.gradle"
   

Be aware: There are two necessary issues associated to your keystore file:

apply(from = "../Signing/keystorePassword.gradle.kts")

apply from: "../Signing/keystorePassword.gradle"

Utilizing Construct Flavors

To be able to create a number of variations of your app, it is advisable to use product flavors. Flavors are a strategy to differentiate the properties of an app, whether or not it’s free/paid, staging/manufacturing, and so on.

You’ll distinguish your app flavors with totally different app names. First, add the next names as strings within the strings.xml file:

<string identify="app_name_free">Socializify Free</string>
<string identify="app_name_paid">Socializify Paid</string>

And take away the present:

<string identify="app_name">Socializify</string>

Now that the unique app_name string is now not obtainable, edit your AndroidManifest.xml file and substitute android:label="@string/app_name" with android:label="${appName}" contained in the utility tag.

Subsequent, add the next code within the android block of your module-level construct.gradle.kts file:

// 1
flavorDimensions.add("appMode")
// 2
productFlavors {
  // 3
  create("free") {
    // 4
    dimension = "appMode"
    // 5
    applicationIdSuffix = ".free"
    // 6
    manifestPlaceholders["appName"] = "@string/app_name_free"
  }
  create("paid") {
    dimension = "appMode"
    applicationIdSuffix = ".paid"
    manifestPlaceholders["appName"] = "@string/app_name_paid"
  }
}

Right here’s what’s taking place within the code above:

1. It is advisable to specify the flavour dimensions to correctly match the construct varieties. On this case, you want just one dimension – the app mode.
2. Within the productFlavors, specify a listing of flavors and their settings. On this case, free and paid.
3. Specify the identify of the primary product taste – free.
4. It’s obligatory to specify the dimension parameter worth. The free taste belongs to the appMode dimension.
5. Because you need to create separate apps without cost and paid performance, you want them to have totally different app identifiers. The applicationIdSuffix parameter defines a string that’ll be appended to the applicationId, giving your app distinctive identifiers.
6. The manifestPlaceholders means that you can modify properties in your AndroidManifest.xml file at construct time. On this case, modify the appliance identify relying on its model.

The Groovy equal can be:

// 1
flavorDimensions = ["appMode"]
// 2
productFlavors {
  // 3
  free {
    // 4
    dimension "appMode"
    // 5
    applicationIdSuffix ".free"
    // 6
    manifestPlaceholders.appName = "@string/app_name_free"
  }
  paid {
    dimension "appMode"
    applicationIdSuffix ".paid"
    manifestPlaceholders.appName = "@string/app_name_paid"
  }
}

Sync your mission with Gradle once more. After the mission sync, run the duties command, and see when you can spot what’s modified:

./gradlew duties

You’ll get an analogous record of duties to the one you bought once you ran this command the primary time:

...
Construct duties
-----------
...
assembleDebug - Assembles important outputs for all Debug variants.
assembleFree - Assembles important outputs for all Free variants.
assemblePaid - Assembles important outputs for all Paid variants.
assembleRelease - Assembles important outputs for all Launch variants.
...

Spot the distinction? Take a look at the duties underneath the Construct duties part, and also you’ll see some new ones there. You now have separate instructions for every construct sort and construct taste.

Run the command:

./gradlew assembleDebug

When the command completes, verify the output listing:

ls -R app/construct/outputs/apk

Right here’s what you’ll see:

free paid

app/construct/outputs/apk/free:
debug

app/construct/outputs/apk/free/debug:
app-free-debug.apk   output-metadata.json

app/construct/outputs/apk/paid:
debug

app/construct/outputs/apk/paid/debug:
app-paid-debug.apk   output-metadata.json

You must have two builds generated – freeDebug and paidDebug.