Sembast for the web

sembast for the Web, NoSQL persistent embedded database for the Web on top of IndexedDB.

Works on browser applications and flutter web applications (js/wasm).

Setup

In pubspec.yaml

dependencies:
  sembast_web: '>=1.0.0'

Usage

import 'package:sembast/sembast.dart';
import 'package:sembast_web/sembast_web.dart';

Future main() async {
  // Declare our store (records are mapd, ids are ints)
  var store = intMapStoreFactory.store();
  var factory = databaseFactoryWeb;

  // Open the database
  var db = await factory.openDatabase('test');

  // Add a new record
  var key =
      await store.add(db, <String, Object?>{'name': 'Table', 'price': 15});

  // Read the record
  var value = await store.record(key).get(db);

  // Print the value
  print(value);

  // Close the database
  await db.close();
}

Features and limitations

  • Use int or key string only
  • Content is synchronized across all open tabs
  • Transactions are cross-tab safe (since 0.1.0+4)
  • Codec are not supported. Web is not safe anyway. Encrypt fields as needed.
  • Transactions must be idempotent (i.e. they must produce the same result if run twice) as they might run again in case of concurrent access.
  • WASM support as of 2.3.0 (legacy html version available through sembast_web_html.dart import)

Use the same web port when debugging

The database is stored in the browser indexeddb. Like any other web storage, it is tied to the port. (i.e. localhost:8080 is different from localhost:8081). When debugging, you should use the same port to keep the same indexeddb database.

How it works

Like sembast the whole database is loaded into memory from indexedDB. It notifies cross tabs using localStorage. data is incrementally updated from indexedDB. If a transaction is ran after some changes happens, new data is loaded and transaction is ran again.

The only exported API is databaseFactoryWeb. For more information on the API see sembast documentation.

Libraries

sembast_web
sembast_web_html
sembast_web_interop