Progress Builder #

A simple wrapper for asynchronous actions with progress/loading indications and error handling.

See a demo at: https://progress-builder.flutter.apexlabs.ai

Usage #

The following will:

• await the Future.delayed()
• show LinearProgressIndicator while it is being awaited
• print 'success' if successful
• print error: ...exception... at random in case of an exception
• print 'done' in all cases

import 'package:progress_builder/progress_builder.dart';

...
          LinearProgressBuilder(
            builder: (action, error) => Column(
              children: [
                ElevatedButton(
                  onPressed: action,
                  child: Text(
                    '50/50 chance of success',
                  ),
                ),
                if (error != null)
                  Container(
                    color: Colors.red,
                    padding: EdgeInsets.all(16.0),
                    child: Text(error.toString()),
                  )
              ],
            ),
            action: (onProgress) async {
              _showMessage('loading undetermined');
              await Future.delayed(const Duration(seconds: 1));
              for (final progress in [10, 20, 30, 40, 50, 60, 70, 80, 90]) {
                _showMessage('loaded $progress%');
                onProgress(100, progress);
                await Future.delayed(const Duration(milliseconds: 500));
              }
              if (_random.nextBool()) {
                throw Exception('Loading failed');
              }
              _showMessage('loaded');
            },
            onDone: () => _showMessage('done'),
            onError: (error) => _showSnackbar('error $error'),
            onSuccess: () => _showSnackbar('success'),
          ),

TODO #

[X] Add documentation on how to use the actual progress value callback

Features and bugs #

Please file feature requests and bugs at the issue tracker.