Usage Examples

deleteList(SqliteDatabase db, String id) async {
  await db.writeTransaction((tx) async {
     // Delete the main list
     await tx.execute('DELETE FROM lists WHERE id = ?', [id]);
     // Delete any children of the list
     await tx.execute('DELETE FROM todos WHERE list_id = ?', [id]);
  });
}

StreamBuilder(
  // You can watch any SQL query
  stream: db.watch('SELECT * FROM customers order by id asc'),
  builder: (context, snapshot) {
    if (snapshot.hasData) {
      // TODO: implement your own UI here based on the result set
      return ...;
    } else {
      return const Center(child: CircularProgressIndicator());
    }
  },
)

FloatingActionButton(
  onPressed: () async {
    await db.execute(
      'INSERT INTO customers(id, name, email) VALUES(uuid(), ?, ?)',
      ['Fred', 'fred@example.org'],
    );
  },
  tooltip: '+',
  child: const Icon(Icons.add),
);

@override
Future<void> uploadData(PowerSyncDatabase database) async {
  final batch = await database.getCrudBatch();
  if (batch == null) return;
  for (var op in batch.crud) {
    switch (op.op) {
      case UpdateType.put:
        // Send the data to your backend service
        // Replace `_myApi` with your own API client or service
        await _myApi.put(op.table, op.opData!);
        break;
      default:
        // TODO: implement the other operations (patch, delete)
        break;
    }
  }
  await batch.complete();
}

class _StatusAppBarState extends State<StatusAppBar> {
  late SyncStatus _connectionState;
  StreamSubscription<SyncStatus>? _syncStatusSubscription;

  @override
  void initState() {
    super.initState();
    _connectionState = db.currentStatus;
    _syncStatusSubscription = db.statusStream.listen((event) {
      setState(() {
        _connectionState = db.currentStatus;
      });
    });
  }

  @override
  void dispose() {
    super.dispose();
    _syncStatusSubscription?.cancel();
  }

  @override
  Widget build(BuildContext context) {
    final statusIcon = _getStatusIcon(_connectionState);

    return AppBar(
      title: Text(widget.title),
      actions: <Widget>[
        ...
        statusIcon
      ],
    );
  }
}

Widget _getStatusIcon(SyncStatus status) {
  if (status.anyError != null) {
    // The error message is verbose, could be replaced with something
    // more user-friendly
    if (!status.connected) {
      return _makeIcon(status.anyError!.toString(), Icons.cloud_off);
    } else {
      return _makeIcon(status.anyError!.toString(), Icons.sync_problem);
    }
  } else if (status.connecting) {
    return _makeIcon('Connecting', Icons.cloud_sync_outlined);
  } else if (!status.connected) {
    return _makeIcon('Not connected', Icons.cloud_off);
  } else if (status.uploading && status.downloading) {
    // The status changes often between downloading, uploading and both,
    // so we use the same icon for all three
    return _makeIcon('Uploading and downloading', Icons.cloud_sync_outlined);
  } else if (status.uploading) {
    return _makeIcon('Uploading', Icons.cloud_sync_outlined);
  } else if (status.downloading) {
    return _makeIcon('Downloading', Icons.cloud_sync_outlined);
  } else {
    return _makeIcon('Connected', Icons.cloud_queue);
  }
}

// Example of using hasSynced to show whether the first sync has completed

/// Global reference to the database
final PowerSyncDatabase db;

bool hasSynced = false;
StreamSubscription? _syncStatusSubscription;

// Use the exposed statusStream
Stream<SyncStatus> watchSyncStatus() {
  return db.statusStream;
}

@override
void initState() {
  super.initState();
  _syncStatusSubscription = watchSyncStatus.listen((status) {
    setState(() {
      hasSynced = status.hasSynced ?? false;
    });
  });
}

@override
Widget build(BuildContext context) {
  return Text(hasSynced ? 'Initial sync completed!' : 'Busy with initial sync...');
}

// Don't forget to dispose of stream subscriptions when the view is disposed
void dispose() {
  super.dispose();
  _syncStatusSubscription?.cancel();
}

import 'package:flutter/material.dart';
import 'package:powersync/powersync.dart' hide Column;

class SyncProgressBar extends StatelessWidget {
  final PowerSyncDatabase db;

  /// When set, show progress towards the [BucketPriority] instead of towards
  /// the full sync.
  final BucketPriority? priority;

  const SyncProgressBar({
    super.key,
    required this.db,
    this.priority,
  });

  @override
  Widget build(BuildContext context) {
    return StreamBuilder<SyncStatus>(
      stream: db.statusStream,
      initialData: db.currentStatus,
      builder: (context, snapshot) {
        final status = snapshot.requireData;
        final progress = switch (priority) {
          null => status.downloadProgress,
          var priority? => status.downloadProgress?.untilPriority(priority),
        };

        if (progress != null) {
          return Center(
            child: Column(
              children: [
                const Text('Busy with sync...'),
                LinearProgressIndicator(value: progress?.downloadedFraction),
                Text(
                    '${progress.downloadedOperations} out of ${progress.totalOperations}')
              ],
            ),
          );
        } else {
          return const SizedBox.shrink();
        }
      },
    );
  }
}