🔔 KMP Notifications Demo

A Kotlin Multiplatform demo showing how to request notification permissions and trigger native local notifications on both Android and iOS — with all the logic written in Kotlin.

This demo proves that KMP isn’t just for sharing ViewModels, you can even handle notifications natively using expect/actual.

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🚀 Features

• ✅ Single Kotlin API for notifications
• 📱 Works on Android and iOS
• 🧩 Uses expect/actual to access native notification frameworks
• 🍏 Minimal Swift code — only an AppDelegate for iOS setup
• ⚡ Fully functional local notifications demo

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🧠 How it works

The shared module defines an expected class:

expect class NotificationService {

  fun showNotification(
    title: String,
    message: String?
  )

  fun requestPermission(
    activity: PlatformActivity,
    onFinished: (Boolean) -> Unit
  )

  suspend fun areNotificationsEnabled(): Boolean
}

Each platform provides its actual implementation.

Android

• Uses NotificationCompat to create and display notifications
• Handles Android 13+ permission requests
• Creates a simple notification channel

iOS

• Uses UNUserNotificationCenter and UIApplication directly from Kotlin
• Requests permission and sends notifications through iOS APIs
• Only requires a tiny bit of Swift in AppDelegate for delegate registration

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🧪 Demo UI

A minimal interface with two buttons:

• Request Permission → calls askForNotificationPermission
• Show Notification → triggers showNotification()
• -ViewModel to call the service and observe if notifications are enabled

You can build it using:

• Compose Multiplatform for a unified UI
  or
• Native SwiftUI / Android XML — both work perfectly with this shared logic

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🛠️ Requirements

• Android Studio Ladybug+ or later
• Xcode 15+
• Kotlin 2.0+
• Compose Multiplatform (optional) if you’re using shared UI

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▶️ Running the demo

Android

Just hit Run from Android Studio and tap the buttons.

iOS

Open the iOS app in Xcode once (to register the AppDelegate), then run:

./gradlew iosDeployIPhoneSimulator

or run it directly from Xcode.

Make sure to allow notifications when prompted.

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💬 Example output

When you press Show Notification, you’ll see:

“Hello, ${getPlatform().name}!” “This is a notification message.”

appearing natively on both platforms.

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🧩 Why this matters

This project demonstrates how Kotlin Multiplatform lets you:

• Access native platform APIs directly from Kotlin
• Replace boilerplate Swift/Kotlin with a single shared implementation
• Keep full control while sharing real functionality

KMP is not just about shared logic — it’s about shared power ⚡

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🏁 Credits

Built with ❤️ by KMP Bits
Follow more Kotlin Multiplatform content on:

• KMP Bits
• Medium