Introduction

When developing an Android app, you will encounter situations where you need to create different flavors to cater to specific requirements, such as setting up environments (like staging, production, etc.). However, there is always something more than just setting up environments; for example, display apps with different icons and titles. Configuring icons and titles for each flavor is another thing that most people would do. If you find yourself struggling with the challenge of “building different flavors” or “setting icons and titles for different flavors”, you’ve come to the right place!

Key Considerations Before Getting Started

1. This article will not cover “App Signing”.

2. This article will not cover “how to use Image Asset Tool to import icon”.

Essential Terms

• Build Variants: the results that Gradle builds based on the product flavors and build types.
• Build Type: different build and packaging settings, such as: release and debug.
• Flavor Dimensions: a concept that’s used in Gradle to define different dimensions or aspects of product flavors. The combination of different dimensions allows you to generate different build variants.

android {
    flavorDimensions "environment", "language"

    productFlavors {
      development {
          dimension "environment"
      }
      production {
          dimension "environment"
      }

      english {
          dimension "language"
      }
      spanish {
          dimension "language"
      }
    }
  }

• Product Flavor: a configuration block in Gradle that allows you to define different flavors or variants for your app.

android {
  productFlavors {
    flavor1 {
      ...
    }
    flavor2 {
      ...
    }
  }
}

• Application Id: a property in Gradle to specify the unique identifier or package name for an Android app.
• Application Suffix: a property in Gradle that appends a suffix to the applicationId property.
• Manifest Placeholders: manifestPlaceholders is a property to provide placeholder values that can be used in AndroidManifest.xml. This property stores data in the format of key-value, which defines data dynamically (for example, setting properties based on their product flavors).

# app/build.gradle

manifestPlaceholders = [
    appIcon: "@mipmap/ic_launcher_red",
    appIconRound: "@mipmap/ic_launcher_red_round"
]

# AndroidManifest.xml

<application
    ...
    android:icon="${appIcon}"
    android:roundIcon="${appIconRound}"
    ...
/>
  ...
</application>

Defining Flavors & Customization

1. Configure buildTypes:

android {
  ...

  buildTypes {
    release {
        signingConfig signingConfigs.release
    }
    debug {
        signingConfig signingConfigs.debug
    }
  }
}

2. Configure signingConfigs:

android {
  ...

  signingConfigs {
    release {
      // Add your configurations here
    }
    debug {
      // Add your configurations here
    }
  }
}

3. Setup flavors by copying the configurations down below under the buildTypes block:

android {
  ...
  
  flavorDimensions "environment"
  productFlavors {
    dev {
        dimension "environment"
        applicationIdSuffix ".dev"
    }
    prod {
        dimension "environment"
        applicationIdSuffix ".prod"
    }
  }
}

4. Adding manifestPlaceholders to flavor blocks in productFlavors block if you want to customize app icons or titles:

android {
  ...

  productFlavors {
    dev {
        ...
        manifestPlaceholders = [
            appLabel: "MyApp (Development)",
            appIcon: "@mipmap/dev_icon",
        ]    }
    prod {
        ...
        manifestPlaceholders = [
            appLabel: "MyApp",
            appIcon: "@mipmap/prod_icon",
        ]    }
  }
}

5. Applying the placeholder values defined in manifestPlaceholders to your AndroidManifest.xml:

<application
    android:label="${appLabel}"
    android:icon="${appIcon}"
    ...
/>
  ...
</application>

6. Adding arguments --flavor <flavor> to your build command. Take flutter run command for instance: flutter run --flavor dev. If you are using Android Studio to build different flavors, don’t forget to add the arguments -- flavor <flavor> to Build Variant panel (You can find it by going to Build > select Build Variant).

Reference

Configure build variants

Basic use of Android Product Flavors/build variants

How to create build variants in Flutter Android so that each build variants have different app id?

Android — app icon for debug and release mode