Flutter Toit API 集成插件 toit_api 的使用

本包提供了通过其 API 访问 Toit 服务器的 gRPC 函数。

示例

以下是一个完整的示例代码，展示了如何使用 toit_api 插件进行登录、设备操作及 PubSub 操作。

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:grpc/grpc.dart';

import 'package:toit_api/toit/api/auth.pbgrpc.dart' show AuthClient, LoginRequest;
import 'package:toit_api/toit/api/pubsub/publish.pbgrpc.dart' show PublishClient, PublishRequest;
import 'package:toit_api/toit/api/pubsub/subscribe.pbgrpc.dart';
import 'package:toit_api/toit/api/device.pbgrpc.dart';

// 将 UUID 转换为字符串格式。
String uuid2String(List<int> bytes) {
  var hex = bytes.map((b) => b.toRadixString(16).padLeft(2, "0")).join();
  return "${hex.substring(0, 8)}-"
      "${hex.substring(8, 12)}-"
      "${hex.substring(12, 16)}-"
      "${hex.substring(16, 20)}-"
      "${hex.substring(20)}";
}

/**
 * 这个应用程序演示了一些更常见的 API 操作。
 */
Future<void> main(List<String> args) async {
  if (args.length != 2) {
    print("用法: main.dart <用户名> <密码>");
    exit(1);
  }

  var username = args[0];
  var password = args[1];
  var channel = ClientChannel('api.toit.io');
  try {
    print("正在登录...");
    var authClient = AuthClient(channel);
    var resp = await authClient
        .login(LoginRequest(username: username, password: password));
    var tokenBytes = resp.accessToken;
    var token = utf8.decode(tokenBytes);
    print("");

    var options = CallOptions(metadata: {'Authorization': 'Bearer $token'});

    print("请求设备列表...");
    var deviceStub = DeviceServiceClient(channel, options: options);
    var deviceList =
        (await deviceStub.listDevices(ListDevicesRequest())).devices;
    for (var device in deviceList) {
      print("  ${device.config.name}");
    }

    if (deviceList.isEmpty) return;

    print("");

    var name = deviceList.first.config.name;
    print("按名称查找设备（$name）...");
    var lookupResponse =
        await deviceStub.lookupDevices(LookupDevicesRequest(deviceName: name));
    var deviceIds = lookupResponse.deviceIds;
    print("");

    // 应该至少有一个匹配项，但可能有多于一个。
    print("找到 ${deviceIds.length} 个匹配项：");
    deviceIds.forEach((deviceId) {
      print("  ${uuid2String(deviceId)}");
    });
    print("");

    var deviceId = deviceIds.first;
    var deviceIdString = uuid2String(deviceId);
    print("检查具有设备 ID $deviceIdString 的设备...");
    var device =
        (await deviceStub.getDevice(GetDeviceRequest(deviceId: deviceId)))
            .device;
    var config = device.config;
    print("  名称: ${config.name}");
    var maxOfflineString = config.connection.maxOffline.toString().trim();
    print("  连接间隔: $maxOfflineString");
    var status = device.status;
    print("  当前是否连接: ${status.connected}");
    var health = status.health;
    var lastSeen = DateTime.fromMillisecondsSinceEpoch(
        health.connectivity.lastSeen.seconds.toInt() * 1000);
    print("  最后一次看到时间: $lastSeen");
    print("  上次检查是否有遗漏: "
        "${health.connectivity.checkins.last.hasMissed()}");
    print("");

    print("PubSub...");
    print("列出现有订阅...");
    var subscribeStub = SubscribeClient(channel, options: options);
    var existingSubscriptions =
        (await subscribeStub.listSubscriptions(ListSubscriptionsRequest()))
            .subscriptions;
    existingSubscriptions.forEach((sub) {
      print("  ${sub.name}: ${sub.topic}");
    });
    print("");

    var topic = "cloud:toit-api/demo";

    if (existingSubscriptions.any((sub) => sub.name == topic)) {
      return;
    }

    print("创建新订阅并发送数据...");
    var subscription =
        Subscription(name: "toit-api-demo 订阅", topic: topic);
    await subscribeStub.createSubscription(
        CreateSubscriptionRequest(subscription: subscription));

    // 只获取当前可用的订阅。
    // 使用 `stream` 函数将不断接收新消息。
    var fetchFuture =
        subscribeStub.fetch(FetchRequest(subscription: subscription));

    var publishStub = PublishClient(channel, options: options);
    await publishStub.publish(PublishRequest(
        topic: topic,
        publisherName: "dart toit-api demo",
        data: [utf8.encode("demo")]));

    print("等待发布的值到达订阅...");
    var fetch = await fetchFuture;
    print(fetch);
    print("确认...");
    await subscribeStub.acknowledge(AcknowledgeRequest(
        subscription: subscription, envelopeIds: [fetch.messages.first.id]));

    print("删除订阅...");
    await subscribeStub.deleteSubscription(
        DeleteSubscriptionRequest(subscription: subscription));
  } finally {
    channel.shutdown();
  }
}