Code sample for 'Use Extension Methods in Dart' lesson on Egghead.io

main.dart

import 'dart:async';

getDuration(int seconds) {
  return Duration(seconds: seconds);
}

extension MyInt on int {
  Duration get seconds => Duration(seconds: this);
  DateTime monthsAgo() => DateTime.now().subtract(Duration(hours: 24 * 30 * this));
}

extension MyString on String {
  bool isValidEmail() => RegExp('^[a-z]*@[a-z]*\.com', caseSensitive: false).hasMatch(this);
//   final notallowed = true;
}

extension MyStreamController<T> on StreamController<T> {
  void set latest(item) => this.add(item);
}

void main() {
  print(getDuration(2));
  
  Future.delayed(getDuration(2), () => print('2 seconds passed'));
  
  print(2.seconds);
  print(MyInt(2).seconds);
  
  Future.delayed(2.seconds, () => print('2 seconds elapsed'));
 
  print(2.monthsAgo());
  print(MyInt(2).monthsAgo());
  
  print('super@gmail.com'.isValidEmail());
  print('notanemail'.isValidEmail());
  
  StreamController<int> controller = StreamController<int>();
  controller.stream.listen((value) => print('Got value $value'));
  
  controller.latest = 5;
  controller.latest = 10;
}