No content

Bridging the Gap: Understanding Method Channels for Flutter and Native Communication 

こんにちは (Hello), My Name is Noman Khan 󰦋 Your Flutter & Native Integration Guru 

🚀 What I Do ● I’m a mobile developer who blends Flutter with native code to craft magical apps. ● An open source contributor, I love sharing my knowledge and improving the tech community. ● Org Admin at The Palisadoes Foundation. 🔍 My Mission ● To unravel the mysteries of Method Channels and make cross-platform development smoother. 🎮 Fun Fact: ● When I’m not coding, you’ll find me gaming or cheering for my favorite cricket team! 

🌏 My Journey 📍 Bihar, India: Growing up in the heartland of India. 🎓 CSE Engineering in New Delhi: Laid the foundation for my tech career and ignited my passion for tech. 🌟 Bangalore (Silicon Valley of India): Advanced my skills in India’s tech hub, driving cutting-edge projects. 󰏦 Japan: Bringing my expertise to the global stage at DroidKaigi! 

2020 Started Mobile Development 2022 Google Summer of Code 2023 Google Summer of Code Mentor 2024 Google Summer of Code Org Admin 2024 International Speaker My Journey as a Developer 󰦋 開発者としての私の歩み 

● Platform channels are the gateway to accessing platform-specific code in Flutter About Platform Channel 󰦋 プラットフォームチャンネルについて ● Flutters offers three types of platform channels for developers to utilize: 1. MethodChannel 2. EventChannel 3. BasicMessageChannel 

● "Platform-specific" refers to features, functionalities, or code that are designed to work specifically on a particular platform, such as Android, iOS, Windows, macOS, or web. What do I mean by platform-specific? 󰦋 プラットフォーム固有とはどういう意味ですか ? ● Accessing device-specific APIs: Such as sensors, camera, battery info, etc. ● Utilizing platform-specific UI components: For example, Android has Material Design, while iOS uses Cupertino design. ● Handling platform-specific features: Features like background tasks, notifications, permissions, or platform-specific storage methods can vary significantly between platforms. 

What is Method Channels? 🧐 Communication Bridge: A Method Channel is primarily for sending messages from Dart to a host platform and getting the results back. It makes integrating platform-specific APIs or libraries with your Flutter app an absolute breeze.. Simple API Calls: Works like calling a function—Flutter sends a message (method call), native code executes it, and then returns the result back to Flutter. 

What is Event Channel ? 🧐 ● One key difference differentiating it from MethodChannel is its ability to communicate continuously from a host platform to Dart. ● When you need to observe platform-side events and reflect changes in your Flutter app. ● It is ideal for scenarios like listening to sensor data, receiving platform notifications, or gathering information from third-party SDKs. 

What is BasicMessageChannel ? 🧐 ● It permits communication in both directions - from Dart to the host platform and vice-versa, lending itself well for use cases where bidirectional communication is needed without getting responses or results. ● It doesn't support directly returning a result or having an event stream, such as method calls or event channels. ● Broadcast messages from your native code to Dart or the reverse direction. 

Platform Channels 🆚 Method Channels ! ● Only one type: Method Channel. ● Synchronous method call-based communication with immediate responses. ● Uses binary message encoding. ● Best for calling functions on the native side and getting immediate results back. ● Includes Method Channels, Basic Message Channels, Event Channels, and Standard Message Channels. ● Can be both synchronous (Method Channels) and asynchronous (Event Channels, etc.). ● can be binary, string messages, or structured data streams. ● Covers broader scenarios including real-time data streams, simple data transfer, and method invocation. Platform Channels Method Channels 

Dart Method Call Handler 🤔 ● A Dart method call handler is a necessary component when operating with method channels. It appoints a function responsible for receiving method calls and giving appropriate responses. 

Use Case of Method Channels 🤔 メソッドチャネルの使用例 ● Access Native Features (Bluetooth, GPS, sensors) ● Integrate with Native SDKs ● Reusability of Existing Code ● Optimize Performance ● Custom Functionality 

No content

Step 1: Create the Flutter platform client How to Implement Method Channel? 󰦋 メソッドチャネルを実装するには ? 

Step 2: Invoke a method on the method channel, specifying the concrete method to call using the String identifier getBatteryLevel. 

Step 3: Call the function in your flutter code. 

Implementing Platform-Specific Code 

Step 4: Open the file MainActivity.kt located in the kotlin folder in the Project view. add the following method in the MainActivity class, below the configureFlutterEngine() method: 

Step 5: create a MethodChannel and call setMethodCallHandler(). Make sure to use the same channel name as was used on the Flutter client side. 

Implementing Platform-Specific Code 

Step 6: Open the file AppDelegate.swift Add the following as a new method at the bottom of AppDelegate.swift: 

Step 7: Override the application:didFinishLaunchingWithOptions: function and create a FlutterMethodChannel tied to the channel name noman.test/battery: 

Best Practices 🎯 ベストプラクティス ● Consistent Channel Names ● Error Handling ● Avoid Channel Blocking ● Use Right Channel for the Right Job ● Keyword Restrictions 

Handling Errors in Platform Channels ⚠ ● we employ a try-catch block to handle possible errors that could arise when we invoke the method MethodName. If a PlatformException is encountered, we print out the error message to our console. 

Why not directly interface Dart code with Java or Swift? 🤔 

Understanding the Direct Communication 📱 ● Direct communication implies writing native code in your Dart files, often using inline strings, and then having Dart interface with this code. This approach could be facilitated using a package like 'ffi'. 

The Power of Flutter Platform Channels 📱 ● Flutter platform channels segregate native code cleanly away from your Dart codebase. ● Flutter inherently supports efficient binary serialization, facilitating high-performance, low-latency communications. 

Handling Non-String Data in Flutter MethodChannel ● The standard message codec in the Flutter platform channel supports efficient binary serialization of simple JSON-like values, which include not just strings but booleans, lists, maps, and even byte buffers. ● It gets serialized to a binary form, transmitted, and then deserialized at the receiver's end. 

No content

Migrating to Flutter Platform Channel 🤔 

Why Migrate? ● They render direct interaction with platform-specific native code, aiding in using specific APIs and delivering a more native-like feel to the apps. Developers can invoke native methods from Dart, harnessing the power of the underlying platform. ● Further, the platform channels bestow greater control over the UI components, leading to user interface enhancements and making your Flutter app more responsive. 

Step-By-Step Migration Guide ● Identify the Components ● Select the Appropriate Channel ● Define the Channel on both Sides ● Set Up the Method Call Handler ● Handle the Method Call in Native Code ● Testing & Debugging 

Thank You!󰚋 ありがとうございます 

Connect with me! 🔗 私とつながってください @noman2002 @nomn2002