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How to set up Feature Flags in Android (Kotlin)

To implement feature flags in an Android app using the Statsig SDK, follow these steps, including creating a basic "Hello World" Android app, integrating Statsig, and managing feature flags in the Statsig console.

Step 1: Create a Basic Android "Hello World" App

  1. Install Android Studio:

    • Download and install Android Studio from the official website. Launch it and follow the setup wizard to install any necessary SDK packages.
  2. Start a New Android Studio Project:

    • Open Android Studio and choose to start a new Android project.
    • Select the "Empty Activity" template and click "Next".
    • Enter your Application name, for example, "HelloWorldApp", and choose a save location.
    • Make sure to select Kotlin as the language and the minimum API level supported by your app. API level 21 (Android 5.0 Lollipop) is a good starting point for broad compatibility.
    • Click "Finish" to create your project.
  3. Modify MainActivity.kt:

    • Open MainActivity.kt and ensure it contains code similar to the following for a basic "Hello World" setup:
      package com.example.helloworldapp

      import androidx.appcompat.app.AppCompatActivity
      import android.os.Bundle
      import android.widget.TextView

      class MainActivity : AppCompatActivity() {
      override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)

      val textView: TextView = findViewById(R.id.textView)
      textView.text = "Hello, World!"
      }
      }
  4. Update the Layout:

    • Ensure res/layout/activity_main.xml is updated to include a TextView with @+id/textView.

Step 2: Integrating Statsig for Feature Flags

  1. Add Statsig SDK Dependency:

    • Open your app's build.gradle (Module: app) file, and add the Statsig SDK dependency to the dependencies block:
      implementation 'com.statsig:android-sdk:1.+'
  2. Initialize Statsig in Your Application:

    • Modify MainActivity.kt to initialize Statsig and check a feature flag:
      import androidx.appcompat.app.AppCompatActivity
      import android.os.Bundle
      import android.widget.TextView
      import com.statsig.androidsdk.Statsig
      import com.statsig.androidsdk.StatsigOptions

      class MainActivity : AppCompatActivity() {

      override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)

      // Initialize Statsig
      Statsig.initialize(
      this.applicationContext,
      "client-sdk-key",
      options = StatsigOptions(initTimeoutMs = 6000)
      ) {
      // Check if a feature flag is enabled
      val isFeatureEnabled = Statsig.checkGate("example_feature_flag")
      runOnUiThread {
      val textView: TextView = findViewById(R.id.textView)
      if (isFeatureEnabled) {
      textView.text = "Feature Enabled!"
      } else {
      textView.text = "Hello, World!"
      }
      }
      }
      }

      override fun onDestroy() {
      super.onDestroy()
      Statsig.shutdown()
      }
      }
    • Replace "client-sdk-key" with your actual Statsig Client SDK Key.
    • Replace "example_feature_flag" with the name of the feature flag you will create.

Step 3: Creating Feature Flags in the Statsig Console

  1. Sign Up/Login to Statsig:

  2. Create a New Project:

    • In the Statsig console, create a new project for your application.
  3. Navigate to Feature Flags:

    • Access the "Feature Flags" section from the dashboard.
  4. Create a New Feature Flag:

    • Click "Create Feature Flag".
    • Enter a name for your feature flag (e.g., example_feature_flag).
    • Configure targeting rules as needed.
    • Save your feature flag.

    image

  5. Toggle Your Feature Flag:

    • You can enable or disable your feature flag from the dashboard and configure it as needed.

This guide outlines creating a simple Android app, integrating Statsig for feature management, and setting up feature flags in the Statsig console. Ensure your client-sdk-key is the client (not server) key meant for client-side use, and always manage feature flags responsibly to provide the best user experience.