What is Flutter?

• mobile app SDK - Android & iOS
• developed by Google
• DART
• open-source on GitHub
• still alpha

Cross-platform frameworks

• WebView based - PhoneGap, Apache Cordova, Ionic, ...
• React Native
• Flutter

Why Flutter?

• IDE plugins
• hot reload
• compatibility - Android 4.1+, iOS 8.0+
• AOT to native code
• full control over the widgets
• provides beautiful, customizable widgets
• single codebase

Findings...

Setup

• https://flutter.io/setup/
• quick & simple

• flutter doctor
  

• flutter create app_name 
     [-a kotlin -i swift -org my.package.name]

• flutter run [--release]

• flutter devices

Channels

• for communication with the platform
• access data, start services, show native UI screen
• send async messages
• https://flutter.io/platform-channels/

Cross-platform libs = Plugins

• SharedPreferences (iOS UserDefaults)
• sqflite
• URL launcher
• HTTP
• Firebase
• ...
• https://pub.dartlang.org/

Localization

• flutter_localization
  • simple solution
• intl & intl_translation
  • gender, plural, fallback to default language

https://flutter.io/tutorials/internationalization/

Testing

• flutter_test
  • https://flutter.io/testing/#unit-testing
  • unit testing
• mockito
  • https://pub.dartlang.org/packages/mockito
  • mock library for dart

• IDE alebo $ flutter test

Video

• flutter lib: 
  • https://pub.dartlang.org/packages/video_player
  • flutter lib
• chewie
  • https://pub.dartlang.org/packages/chewie
  • 3rd party lib with controlls

Reflection vs Code Generation

• reflection is not supported
  • all libs use code generation
• dart tree-shaking
  • include large lib, use only what you need

API

• http
  • https://pub.dartlang.org/packages/http
  • Future-based library for making HTTP requests
    • simple
    • easy request/response interception
    • header manipulation
    • no cookie manager lib
• JSON support
  • https://flutter.io/json/
  • manually or via library
    • json_serializable : https://pub.dartlang.org/packages/json_serializable

Resources

• shared assets for flutter part
• support for 1.0x, 2.0x a 3.0x image variants
• great library of material design icons
• no SVG support
  • (open issue: https://github.com/flutter/flutter/issues/1831)

Build Flavors

• define in each platform
• propagate through a channel (no plugin yet)
  • no flavor specific code/asset directory support

$ flutter run --flavor free

$ flutter run --flavor paid

Debugging & Profiling

• open flutter project in AndroidStudio (IntelliJ)
  • flutter plugin adds:
    • toggle platform, slow animation, debug paint, performance overlay, widget hierarchy
  • dart only debugging
  • AndroidStudio profiler is hidden
• open android part in AndroidStudio / iOS in Xcode

Background processing

• run Dart code in a background service
• implementation is in-progress
• open issues:
  • https://github.com/flutter/flutter/issues/6192
  • https://github.com/flutter/flutter/issues/3671
• AlarmManager plugin for Android only: https://github.com/flutter/plugins/tree/master/packages/android_alarm_manager

Logging

• dart lib: https://pub.dartlang.org/packages/logging

WebView support

• no inline view support yet: https://github.com/flutter/flutter/issues/730
• plugin : https://github.com/dart-flitter/flutter_webview_plugin
  • using platform specific screen overlay
  • load html: https://github.com/dart-flitter/flutter_webview_plugin/issues/23#issuecomment-367618709