Dart Singleton 带参数（全局应用记录器）

Question

I'd like to use the Logger library in my app. I only want to instasiate it once so that I have consistent formatting across my app, instead of passing PrettyPrinter in each file I use it. What is the right way of doing this? Should I just use a global const? Is there a way to do this using a Singleton?

Answer 1

I define a helper function to get the Logger:

import 'package:logger/logger.dart';
import 'log_printer.dart';

Logger getLogger(String className) {
  return Logger(printer: SimpleLogPrinter(className));
}

Then in each class where I want logging for eaxmple:

class ProfileService with ChangeNotifier {
  static final _log = getLogger('ProfileService');

  Future<Profile> updateProfile(Profile profile) async {
    _log.v('updateProfile');
    ...
  }
  ...
}

Another example:

class AuthScreen extends StatelessWidget {
  final log = getLogger('AuthScreen');

  @override
  Widget build(BuildContext context) {
    log.v('build called');
    ...
  }
  ...
}