How to set up analytics in Android

Mar 01, 2024

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Product analytics enable you to gather and analyze data about how users interact with your Android app. To show you how to set up analytics, in this tutorial we create a basic Android app with Kotlin, add PostHog, and use it to capture events and create insights.

1. Create a new Android app

Our app will have two screens:

  • a login screen with a form to enter in your name, email, and company name.
  • a home screen with submit button, toggle, and logout button.

The first step is to create a new app. Open Android Studio and create a new project. Select Empty Activity, name your project Android-Analytics, and use the defaults for everything else.

Then, create a new activity HomeActivity by clicking File > New > Activity > Empty Views Activity. Replace the code in the new activity with the following:

HomeActivity.kt
package com.example.android_analytics


import android.content.Context
import android.content.Intent
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import android.widget.Button
import android.widget.Toast
import android.widget.ToggleButton


class HomeActivity : AppCompatActivity() {


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


        val submitButton = findViewById<Button>(R.id.submitButton)
        val toggleButton = findViewById<ToggleButton>(R.id.toggleButton)
        val logoutButton = findViewById<Button>(R.id.logoutButton)


        submitButton.setOnClickListener {
            Toast.makeText(this, "Submitted", Toast.LENGTH_SHORT).show()
        }


        logoutButton.setOnClickListener {
            val sharedPreferences = getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)
            sharedPreferences.edit().clear().apply()


            // Navigate back to MainActivity
            val intent = Intent(this, MainActivity::class.java)
            startActivity(intent)
            finish()
        }
    }
}

Then we define the UI for our HomeActivity. Update the code in activity_home.xml in the app/res/layout directory with the following:

app/res/layout/activity_home.xml
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">


    <Button
        android:id="@+id/submitButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Submit"/>


    <ToggleButton
        android:id="@+id/toggleButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textOff="Off"
        android:textOn="On"/>


    <Button
        android:id="@+id/logoutButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Logout"/>
</LinearLayout>

Next, we set up our login page in MainActivity. Replace the code in MainActivity.kt with the following:

MainActivity.kt
package com.example.android_analytics


import android.content.Context
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import android.widget.Button
import android.widget.EditText
import android.content.Intent


class MainActivity : AppCompatActivity() {


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


        val sharedPreferences = getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)
        if (sharedPreferences.contains("Name")) {
            // User is already logged in, navigate to HomeActivity
            val homeIntent = Intent(this, HomeActivity::class.java)
            startActivity(homeIntent)
            finish()
        }


        val nameEditText = findViewById<EditText>(R.id.nameEditText)
        val emailEditText = findViewById<EditText>(R.id.emailEditText)
        val companyEditText = findViewById<EditText>(R.id.companyEditText)
        val loginButton = findViewById<Button>(R.id.loginButton)


        loginButton.setOnClickListener {
            val sharedPreferences = getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)
            val editor = sharedPreferences.edit()


            editor.putString("Name", nameEditText.text.toString())
            editor.putString("Email", emailEditText.text.toString())
            editor.putString("Company", companyEditText.text.toString())
            editor.apply()


            val intent = Intent(this@MainActivity, HomeActivity::class.java)
            startActivity(intent)
            finish()
        }
    }
}

Similarly to the HomeActivity, we define the layout for our MainActivity. Create a new file activity_main.xml in the app/res/layout directory. Then add the following code to it:

app/res/layout/activity_main.xml
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">


    <EditText
        android:id="@+id/nameEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Name"/>


    <EditText
        android:id="@+id/emailEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Email"
        android:inputType="textEmailAddress"/>


    <EditText
        android:id="@+id/companyEditText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Company Name"/>


    <Button
        android:id="@+id/loginButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Login"/>
</LinearLayout>

Add the following dependencies to your app/build.gradle (Module: app) and then sync your project with the changes:

app/build.gradle
Lastly, update the `themes.xml` file located in the `res/values` folder to ensure our theme extends `Theme.AppCompat`. We also define the app colors here:


```xml themes.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
    <style name="Theme.AndroidAnalytics" parent="Theme.AppCompat.Light.DarkActionBar">
        <item name="colorPrimary">@color/purple_500</item>
        <item name="colorPrimaryVariant">@color/purple_700</item>
        <item name="colorOnPrimary">@color/white</item>
    </style>
</resources>

Our basic set up is now complete. Build and run your app to see it in action.

Basic setup of the Android app

2. Add PostHog to your app

First, add the PostHog Android SDK as a dependency in your Gradle Scripts/build.gradle.kts (Module: app) file. You can find the latest version on our GitHub. For this tutorial, we use version 3.1.7.

app/build.gradle
dependencies {
    implementation("com.posthog:posthog-android:3.+")
    //... other dependencies
}

Sync your project with the Gradle file changes.

Next, we create a Kotlin class where we can configure our PostHog instance. In the src/main/java/com.example.android_analytics folder, add a new file MyAndroidAnalyticsApplication.kt and then add the following code:

MyAndroidAnalyticsApplication.kt
package com.example.android_analytics


import android.app.Application
import com.posthog.android.PostHogAndroid
import com.posthog.android.PostHogAndroidConfig


class MyAndroidAnalyticsApplication : Application() {
    companion object {
        private const val POSTHOG_API_KEY = "<ph_project_api_key>"
        // usually 'https://us.i.posthog.com' or 'https://eu.i.posthog.com'
        private const val POSTHOG_HOST = "https://us.i.posthog.com"
    }


    override fun onCreate() {
        super.onCreate()
        val config = PostHogAndroidConfig(
            apiKey = POSTHOG_API_KEY,
            host = POSTHOG_HOST
        )
        PostHogAndroid.setup(this, config)
    }
}

To get your PostHog API key and host, sign up to PostHog. Then, you can find your API key and host in your project settings.

We now need to register our custom application class. Go to app/manifests/AndroidManifest.xml and add android:name=".MyAndroidAnalyticsApplication" within the <application tag:

app/manifests/AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <!-- ... rest of the config -->
    <application
        android:name=".MyAndroidAnalyticsApplication"
        <!-- ... rest of the config -->
    </application>
</manifest>

To check your setup, build and run your app. Click your button a few times. You should start seeing events in the activity tab.

Events captured in PostHog

3. Implement the event capture code

To show how to capture events with PostHog, we capture an event when the submit button on the home page is clicked. To do this, we call PostHog.capture():

HomeActivity.kt
// rest of your imports
import com.posthog.PostHog


class HomeActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        
        // ...


        submitButton.setOnClickListener {
            PostHog.capture(event = "home_button_clicked")
            Toast.makeText(this, "Submitted", Toast.LENGTH_SHORT).show()
        }


        // ...

Reload your app and click the button on the home page a few times. You should now see the captured event in your PostHog activity tab.

Setting event properties

When capturing events, you can optionally include additional information by setting the properties argument. This is helpful for breaking down or filtering events when creating insights.

As an example, we add the value of the toggle as an event property:

HomeActivity.kt
// rest of your imports
import com.posthog.PostHog


class HomeActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        
        // ...


        submitButton.setOnClickListener {
            val isToggleOn = toggleButton.isChecked
            PostHog.capture(
                event = "home_button_clicked",
                properties= mapOf("is_toggled_enabled" to isToggleOn)
            )
        }


        // ...

Identifying users

Linking events to specific users enables you to build a full picture of how they're using your product across different sessions, devices, and platforms. To link events from anonymous to specific users, we call PostHog.identify() with a distinctId argument. The distinctId must be a unique identifier for the user – usually their email or database ID.

To show you an example, update the code for the login button to the following:

MainActivity.kt
// rest of your imports
import com.posthog.PostHog
class MainActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        // ...


        loginButton.setOnClickListener {
            val email = emailEditText.text.toString().trim()
            PostHog.identify(email)
            
            // rest of your code
        }

Any past or future events captured after calling identify will now be associated with the email you provided.

To test this, press logout, fill the form in and press login. Then, in the home page, press the submit button to capture the home_button_clicked event. You should now see the email in the Person column in your activity tab.

Identified events captured in PostHog

Lastly, when the user logs out, you should call PostHog.reset(). This resets the PostHog ID and ensures that events are associated to the correct user.

HomeActivity.kt
logoutButton.setOnClickListener {
            val sharedPreferences = getSharedPreferences("AppPrefs", Context.MODE_PRIVATE)
            sharedPreferences.edit().clear().apply()
            
            PostHog.reset()


            // Navigate back to MainActivity
            val intent = Intent(this, MainActivity::class.java)
            startActivity(intent)
            finish()
        }

Capturing group analytics

Groups are a powerful feature in PostHog that aggregate events based on entities, such as organizations or companies. This is especially helpful for B2B SaaS apps, where often you want to view insights such as number of active companies or company churn rate.

To enable group analytics, you'll need to upgrade your PostHog account to include them. This requires entering your credit card, but don't worry, we have a generous free tier of 1 million events per month – so you won't be charged anything yet.

To create groups in PostHog, simply include them in your code by calling PostHog.group():

MainActivity.kt
class MainActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        // ...


        loginButton.setOnClickListener {
            val email = emailEditText.text.toString().trim()
            PostHog.identify(email)


          PostHog.group(
              type = "company", 
              key = companyEditText.text.toString()
          )


            // rest of your code
        }

In the above example, we create a group type company, and then set the value as the unique identifier for that specific company. Any future events that are captured will now be associated with this company.

4. Create an insight in PostHog

Restart your app and capture events using different inputs in the login screen. This will capture events for different users and companies and enable us to show the power of PostHog insights.

Next, go to the Product analytics tab in PostHog and click the + New insight button. PostHog supports many different types of insights, such as trends, funnels, paths and more.

In this tutorial, we create a simple trend insight:

  1. Select the Trends tab.
  2. Under the Series header select the home_button_clicked event.
  3. Click the Total count dropdown to change how events are aggregated. You can choose options such as Count per user, Unique users, Unique company(s), and more. You can also add filters or breakdown based on properties.

For example, in the image below we set our insight to show number of unique users that captured the home_button_clicked event where the toggled is enabed:

Insight created in PostHog

That's it! Feel free to play around in your dashboard and explore the different kinds of insights you can create in PostHog.

Further reading

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