scratch.txt

public class SensorHub : Hub
{
	private readonly SensorCollection _sensorCollection;

	public SensorHub(SensorCollection sensorCollection)
	{
		_sensorCollection = sensorCollection;
	}

	public IEnumerable<string> GetSensorNames()
	{
		return _sensorCollection.GetSensorNames();
	}

	public IAsyncEnumerable<double> GetSensorData(string sensorName, CancellationToken cancellationToken)
	{
		return _sensorCollection.GetSensorData(sensorName, cancellationToken);
	}

	public async Task PublishSensorData(string sensorName, IAsyncEnumerable<double> sensorData)
	{
		try
		{
			await foreach (var measurement in sensorData)
			{
				_sensorCollection.PublishSensorData(sensorName, measurement);
			}
		}
		finally
		{
			_sensorCollection.DisconnectSensor(sensorName);
		}
	}
}

class Program
{
	static async Task Main(string[] args)
	{
		var hubConnectionBuilder = new HubConnectionBuilder()
			.WithUrl("https://localhost:5001/sensors");

		await using var hubConnection = hubConnectionBuilder.Build();
		await hubConnection.StartAsync();

		await hubConnection.SendAsync("PublishSensorData", args[0], GenerateSensorData());

		Console.ReadLine();
	}

	static async IAsyncEnumerable<double> GenerateSensorData()
	{
		var rng = new Random();

		while (true)
		{
			yield return rng.NextDouble() * 10;
			await Task.Delay(1000);
		}
	}
}

<script>
	(async () => {
		const latestSensorData = { x: 0, y: 0, z: 0 };

		const connection = new signalR.HubConnectionBuilder()
			.withUrl("/sensors")
			.configureLogging(signalR.LogLevel.Information)
			.build();

		function subscribeToSensor(sensorName) {
			connection.stream("GetSensorData", sensorName)
				.subscribe({
					next: (item) => {
						console.log(`${sensorName}: ${item}`);
						latestSensorData[sensorName] = item;
					},
					complete: () => {
						console.log(`${sensorName} Completed`);
					},
					error: (err) => {
						console.log(`${sensorName} error: "${err}"`);
					},
				});
		}

		await connection.start();

		const sensorNames = await connection.invoke("GetSensorNames");

		sensorNames.forEach(subscribeToSensor);
		connection.on("SensorAdded", subscribeToSensor);

		startRealTimeLineChart(latestSensorData);
	})();
</script>


# With Auto Reconnect

class Program
{
	static async Task Main(string[] args)
	{
		var hubConnectionBuilder = new HubConnectionBuilder()
			.WithUrl("https://localhost:5001/sensors")
			.WithAutomaticReconnect();

		await using var hubConnection = hubConnectionBuilder.Build();

		hubConnection.Reconnected += async connectionId => {
			await hubConnection.SendAsync("PublishSensorData", args[0], GenerateSensorData());
		};

		await hubConnection.StartAsync();

		await hubConnection.SendAsync("PublishSensorData", args[0], GenerateSensorData());

		Console.ReadLine();
	}

	static async IAsyncEnumerable<double> GenerateSensorData()
	{
		var rng = new Random();

		while (true)
		{
			yield return rng.NextDouble() * 10;
			await Task.Delay(1000);
		}
	}
}

<script>
	(async () => {
		const latestSensorData = { x: 0, y: 0, z: 0 };

		const connection = new signalR.HubConnectionBuilder()
			.withUrl("/sensors")
			.withAutomaticReconnect()
			.configureLogging(signalR.LogLevel.Information)
			.build();

		function subscribeToSensor(sensorName) {
			connection.stream("GetSensorData", sensorName)
				.subscribe({
					next: (item) => {
						console.log(`${sensorName}: ${item}`);
						latestSensorData[sensorName] = item;
					},
					complete: () => {
						console.log(`${sensorName} Completed`);
					},
					error: (err) => {
						console.log(`${sensorName} error: "${err}"`);
					},
				});
		}

		connection.onreconnected(async connectionId => {
			const sensorNames = await connection.invoke("GetSensorNames");
			sensorNames.forEach(subscribeToSensor);
		});

		await connection.start();

		const sensorNames = await connection.invoke("GetSensorNames");

		sensorNames.forEach(subscribeToSensor);
		connection.on("SensorAdded", subscribeToSensor);

		startRealTimeLineChart(latestSensorData);
	})();
</script>