Understanding Flutter Plugins, The Federated Way

Most of the time we are dependent on some framework or libraries for building the software & Flutter apps are no exception to it. In this talk we will understand the fundamentals of such a library or framework (known as Packages / Plugins in Flutter ecosystem). Besides this we will explore more scalable solutions to build packages which support multiple platforms. Also we will shed light on some common How-tos like: debug, test, versioning & publishing of Plugins.

Transcript

1. Understanding Flutter Plugins, The Federated Way Smit Sonani Senior Software Engineer, HighLevel @SmitSonani
2. 🗺 Roadmap • Packages & Plugins • Federated Plugins • Communication • Create Federated Plugins • Android Embedding v2 • 🔌 In Action • Publish Plugins • Key Takeaways
3. Packages & Plugins
4. Packages ◦ Reusability - reduces the efforts of solving the same problem. ◦ Comprehensive maintainability ◦ Might not need platform features, can be pure Dart. Plugins ◦ A special type of package which makes platform features available to the app ◦ Requires native platform implementation skills
5. Federated Plugins
6. Overview • Divides responsibilities into primarily 3 layers ◦ Platform Interface package ◦ App-facing package ◦ Platform specific plugin • Easy to collaborate with, domain experts can take care of specific platform plugin • Easy to support multiple platforms • Endorsed vs. Non-Endorsed
7. Architecture Image source: medium.com
8. App-Facing Package • Exposes the features of the plugins to the Flutter app. • This package goes as a dependency in the app. • Pure Dart • Depends on Platform Interface package & Platform Plugin packages • Should contain an example app demonstrating features provided by the plugin.
9. Platform Interface • Acts as a common interface between app-facing package & platform specific plugins. • The default implementation for Platform Channels goes in this package. • Pure Dart • Depends on plugin_platform_interface
10. • Implements platform specific features at native side • Requires platform specific development skills • The web plugin is an exception. It can be written in Dart which compiles to JS. Platform Plugin(s)
11. Communication via Platform Channels
12. Key Components • Channel ◦ A bridge between the Flutter app & the platform ◦ Bidirectional message passing • Codec ◦ Encodes & Decodes data being sent via channel ◦ Default - StandardMessageCodec • Messenger ◦ Sends data via channel ◦ BinaryMessenger
13. Types of Channels • MethodChannel ◦ One time operations ◦ Use cases ▪ Get something from the platform or vice-versa ▪ Trigger something on the platform or vice-versa ◦ OptionalMethodChannel • EventChannel ◦ Streaming data from a platform to the Flutter app. ◦ Use cases ▪ Continuously listen for updates from platform side. i.e. location changes
14. Image source: flutter.dev
15. StandardMessageCodec - supported data types Source: flutter.dev
16. Pigeon • A code gen tool for better type safe communication • Uses StandardMessageCodec • Supports Android & iOS only at moment • Created by Flutter team • Example
17. Let’s Create Federated Plugins
22. Android Embedding v2
23. Image source: medium.com
24. 🔌 In Action
25. Publish Plugins
27. Best Practices [based on pub.dev - score] • Provide valid files: pubspec.yaml, README.md, CHANGELOG.md • Documentation of public methods • Supports multi-platform [For app facing package] • Code has no errors, warnings, lints, or formatting issues • Dependencies should be up-to-date • Null-Safe
28. Key Takeaways • Method Channels for one time operations • Event Channels for streaming data from platform side • Android embedding v2 for better lifecycle management • FlutterApplicationLifeCycleDelegate for iOS app lifecycle • example app for development, debugging & testing the native code • Don’t forget to --dry-run before publishing to pub.dev
29. Useful Links • Packages & Plugins • Modern Flutter Plugin Development • Supported Devices - Demo Plugin
30. Q & A
31. Thank You! Smit Sonani Senior Software Engineer, HighLevel @SmitSonani