binance_futures 0.0.1

Unofficial Dart wrapper for Binance SPOT API (REST endpoints + Websockets).

example/example.dart

import 'dart:async';

import 'package:binance_futures/binance_futures.dart';
import 'package:flutter/material.dart' hide Interval;

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  BinanceFutures binanceFutures = BinanceFutures(
    key: "<apiKey>",
    secret: "<apiSecret>",
  );
  double lastClosePrice = 0;
  String tradablePairs = "";
  String lastEventData = "";
  late StreamSubscription<dynamic> klineStreamSub;
  late StreamSubscription<dynamic> userdataStreamSub;
  @override
  void initState() {
    startKlineStream();
    startUserdataStream();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text("Binance API tester"),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          crossAxisAlignment: CrossAxisAlignment.center,
          children: [
            Text("Current BTC price : $lastClosePrice"),
            Text("Last userdataStream event : $lastEventData"),
            TextButton(
              onPressed: getTradablePairs,
              child: const Text("GET PAIRS"),
            ),
            Expanded(
              flex: 1,
              child: SelectableText(
                tradablePairs,
                maxLines: 200,
                minLines: 1,
              ),
            ),
          ],
        ),
      ),
    );
  }

  void startKlineStream() {
    var stream = binanceFutures.klineStream(
      symbol: "BTCUSDT",
      interval: Interval.INTERVAL_5m,
    );
    klineStreamSub = stream.listen(handleNewKline);
  }

  void handleNewKline(WsKlineEvent event) {
    setState(() {
      lastClosePrice = event.kline.close;
    });
  }

  void startUserdataStream() async {
    var response = await binanceFutures.createListenKey();
    if (response.isRight) {
      var stream = binanceFutures.userDataStream(listenKey: response.right);
      userdataStreamSub = stream.listen(handleUserdataEvent);
    } else {
      lastEventData = response.left;
    }
  }

  void handleUserdataEvent(dynamic event) {
    if (event is WsAccountUpdateEvent) {
      lastEventData =
          "Account update event : ${event.data.balanceUpdates.length} balances updated";
    } else if (event is WsOrderUpdateEvent) {
      lastEventData =
          "Order update event : order on ${event.orderUpdate.symbol} pair updated";
    } else {
      lastEventData = "Other event type : ${event.toString()}";
    }
  }

  void getTradablePairs() async {
    var response = await binanceFutures.exchangeInformation();
    if (response.isLeft) {
      tradablePairs = response.left;
    } else {
      var listSymbol = response.right.symbols.map((e) => e.symbol).toList();
      tradablePairs = "";
      for (var s in listSymbol) {
        tradablePairs += "$s ";
      }
    }
  }

  @override
  void dispose() {
    klineStreamSub.cancel();
    userdataStreamSub.cancel();
    super.dispose();
  }
}