public async static void Run([EventGridTrigger] EventGridEvent eventGridEvent, ILogger log)
{
log.LogInformation(eventGridEvent.Data.ToString());
if (adtInstanceUrl == null)
{
log.LogError("Application setting \"ADT_SERVICE_URL\" not set");
return;
}
try
{
// INSERT authentication code below here
ManagedIdentityCredential cred = new ManagedIdentityCredential("https://digitaltwins.azure.net");
DigitalTwinsClient client = new DigitalTwinsClient(new Uri(adtInstanceUrl), cred, new DigitalTwinsClientOptions {
Transport = new HttpClientTransport(httpClient)
});
log.LogInformation($"Azure digital twins service client connection created.");
// INSERT event processing code below here
if (eventGridEvent != null && eventGridEvent.Data != null)
{
// Read deviceId and temperature for IoT Hub JSON.
JObject deviceMessage = (JObject)JsonConvert.DeserializeObject(eventGridEvent.Data.ToString());
string deviceId = (string)deviceMessage["systemProperties"]["iothub-connection-device-id"];
var fanAlert = (bool)deviceMessage["properties"]["fanAlert"]; // cast directly to a bool
var temperatureAlert = deviceMessage["properties"].SelectToken("temperatureAlert") ?? false; // JToken object
var humidityAlert = deviceMessage["properties"].SelectToken("humidityAlert") ?? false; // JToken object
log.LogInformation($"Device:{deviceId} fanAlert is:{fanAlert}");
log.LogInformation($"Device:{deviceId} temperatureAlert is:{temperatureAlert}");
log.LogInformation($"Device:{deviceId} humidityAlert is:{humidityAlert}");
var bodyJson = Encoding.ASCII.GetString((byte[])deviceMessage["body"]);
JObject body = (JObject)JsonConvert.DeserializeObject(bodyJson);
log.LogInformation($"Device:{deviceId} Temperature is:{body["temperature"]}");
log.LogInformation($"Device:{deviceId} Humidity is:{body["humidity"]}");
// INSERT ADT update code below here
// Update twin properties
var patch = new Azure.JsonPatchDocument();
patch.AppendReplace <bool>("/fanAlert", fanAlert); // already a bool
patch.AppendReplace <bool>("/temperatureAlert", temperatureAlert.Value <bool>()); // convert the JToken value to bool
patch.AppendReplace <bool>("/humidityAlert", humidityAlert.Value <bool>()); // convert the JToken value to bool
await client.UpdateDigitalTwinAsync(deviceId, patch);
// publish telemetry
await client.PublishTelemetryAsync(deviceId, null, bodyJson);
}
}
catch (Exception e)
{
log.LogError(e.Message);
}
}
public async void Run([EventGridTrigger] EventGridEvent eventGridEvent, ILogger log)
{
//log.LogInformation("Starting function");
//log.LogInformation(eventGridEvent.Data.ToString());
if (adtInstanceUrl == null)
{
log.LogError("Application setting \"ADT_SERVICE_URL\" not set");
}
try
{
//Authenticate with Digital Twins.
//log.LogInformation("Starting ManagedIdentityCredential");
ManagedIdentityCredential cred = new ManagedIdentityCredential("https://digitaltwins.azure.net");
//log.LogInformation("Starting DigitalTwinsClient to: " + adtInstanceUrl.ToString());
DigitalTwinsClient client = new DigitalTwinsClient(new Uri(adtInstanceUrl), cred, new DigitalTwinsClientOptions {
Transport = new HttpClientTransport(httpClient)
});
log.LogInformation($"Azure digital twins service client connection created.");
if (eventGridEvent != null && eventGridEvent.Data != null)
{
//log.LogInformation(eventGridEvent.Data.ToString());
// Read deviceId and temperature for IoT Hub JSON.
JObject deviceMessage = (JObject)JsonConvert.DeserializeObject(eventGridEvent.Data.ToString());
String body = Base64StringDecode(deviceMessage["body"].ToString());
JObject deviceMessageBody = (JObject)JsonConvert.DeserializeObject(body);
//log.LogInformation(body);
string deviceId = (string)deviceMessage["systemProperties"]["iothub-connection-device-id"];
var temperature = deviceMessageBody["Temperature"];
log.LogInformation($"Device:{deviceId} Temperature is:{temperature}");
//Update twin by using device temperature.
var patch = new Azure.JsonPatchDocument();
patch.AppendReplace <double>("/Temperature", temperature.Value <double>());
await client.UpdateDigitalTwinAsync(deviceId, patch);
}
}
catch (Exception e)
{
log.LogError(e.Message);
}
}
public async static Task Run(
[EventGridTrigger] EventGridEvent eventGridEvent,
ILogger log)
{
// The ILogger interface is defined in the
// Microsoft.Extensions.Logging namespace and aggregates most
// logging patterns to a single method call. In this case, a log
// entry is created at the Information level - other methods
// exists for various levels including critical, error. etc. As the
// Azure Function is running in the cloud, logging is essential
// during development and production.
log.LogInformation(eventGridEvent.Data.ToString());
// This code checks if the adtInstanceUrl environment variable
// has been set - if not, the error is logged and the function exits.
// This demonstrates the value of logging to capture the fact that
// the function has been incorrectly configured.
if (adtInstanceUrl == null)
{
log.LogError("Application setting \"ADT_SERVICE_URL\" not set");
return;
}
try
{
// REVIEW authentication code below here
// Notice the use of the ManagedIdentityCredential class.
// This class attempts authentication using the managed identity
// that has been assigned to the deployment environment earlier.
// Once the credential is returned, it is used to construct an
// instance of the DigitalTwinsClient. The client contains
// methods to retrieve and update digital twin information, like
// models, components, properties and relationships.
ManagedIdentityCredential cred =
new ManagedIdentityCredential("https://digitaltwins.azure.net");
DigitalTwinsClient client =
new DigitalTwinsClient(
new Uri(adtInstanceUrl),
cred,
new DigitalTwinsClientOptions {
Transport = new HttpClientTransport(httpClient)
});
log.LogInformation($"Azure digital twins service client connection created.");
// REVIEW event processing code below here
if (eventGridEvent != null && eventGridEvent.Data != null)
{
// Read deviceId and temperature for IoT Hub JSON.
// Notice the use of JSON deserialization to access the event data.
// The message properties and systemProperties are
// easily accessible using an indexer approach.
JObject deviceMessage = (JObject)JsonConvert.DeserializeObject(eventGridEvent.Data.ToString());
string deviceId = (string)deviceMessage["systemProperties"]["iothub-connection-device-id"];
var fanAlert = (bool)deviceMessage["properties"]["fanAlert"]; // cast directly to a bool
// However where properties are optional, such as temperatureAlert
// and humidityAlert, the use of `SelectToken` and a
// null-coalescing operation is required to prevent an
// exception being thrown.
var temperatureAlert = deviceMessage["properties"].SelectToken("temperatureAlert") ?? false; // JToken object
var humidityAlert = deviceMessage["properties"].SelectToken("humidityAlert") ?? false; // JToken object
log.LogInformation($"Device:{deviceId} fanAlert is:{fanAlert}");
log.LogInformation($"Device:{deviceId} temperatureAlert is:{temperatureAlert}");
log.LogInformation($"Device:{deviceId} humidityAlert is:{humidityAlert}");
// The message body contains the telemetry payload and is
// ASCII encoded JSON. Therefore, it must first be decoded and
// then deserialized before the telemetry properties can be accessed.
var bodyJson = Encoding.ASCII.GetString((byte[])deviceMessage["body"]);
JObject body = (JObject)JsonConvert.DeserializeObject(bodyJson);
log.LogInformation($"Device:{deviceId} Temperature is:{body["temperature"]}");
log.LogInformation($"Device:{deviceId} Humidity is:{body["humidity"]}");
// REVIEW ADT update code below here
// There are two approaches being used to apply data to the
// digital twin - the first via property updates using a JSON
// patch, the second via the publishing of telemetry data.
// The ADT client utilizes a JSON Patch document to add or
// update digital twin properties. The JSON Patch defines a
// JSON document structure for expressing a sequence of
// operations to apply to a JSON document. The various values
// are added to the patch as append or replace operations,
// and the ADT is then updated asynchronously.
var patch = new Azure.JsonPatchDocument();
patch.AppendReplace <bool>("/fanAlert", fanAlert); // already a bool
patch.AppendReplace <bool>("/temperatureAlert", temperatureAlert.Value <bool>()); // convert the JToken value to bool
patch.AppendReplace <bool>("/humidityAlert", humidityAlert.Value <bool>()); // convert the JToken value to bool
await client.UpdateDigitalTwinAsync(deviceId, patch);
// publish telemetry
// Notice that the telemetry data is handled differently than
// the properties - rather than being used to set digital twin
// properties, it is instead being published as telemetry
// events. This mechanism ensures that the telemetry is
// available to be consumed by any downstream subscribers to
// the digital twins event route.
await client.PublishTelemetryAsync(deviceId, null, bodyJson);
}
}
catch (Exception e)
{
log.LogError(e.Message);
}
}