feat: add source model information on relationship's event

Author: AndreaGiulianelli

adt-event-endpoint-function/AdtEventEndpoint.cs

@@ -1,3 +1,8 @@
+using System;
+using System.Net.Http;
+using Azure.Core.Pipeline;
+using Azure.DigitalTwins.Core;
+using Azure.Identity;
 using Azure.Messaging;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Http;
@@ -9,6 +14,8 @@
 using Newtonsoft.Json.Linq;
 using Microsoft.Azure.WebJobs.Extensions.SignalRService;
 
+
+
 namespace AdtEventEndpoint
 {
     public static class AdtEventEndpoint
@@ -42,6 +49,18 @@ public static Task Observe(
             eventToClients.Add("id", eventGridEvent.Subject);
             eventToClients.Add("eventType", eventGridEvent.Type);
             eventToClients.Add("eventDateTime", eventGridEvent.Time.ToString());
+
+            // When the event involve the creation or the deletion of a reletionship then get the source's model.
+            if(eventGridEvent.Type.StartsWith("Microsoft.DigitalTwins.Relationship")) {
+                DigitalTwinsClient client = new DigitalTwinsClient(
+                    new Uri(Environment.GetEnvironmentVariable("ADT_SERVICE_URL")),
+                    new DefaultAzureCredential(),
+                    new DigitalTwinsClientOptions{ Transport = new HttpClientTransport(new HttpClient()) });
+
+                string sourceId = eventToClients["data"]["$sourceId"].ToString();
+                BasicDigitalTwin sourceDigitalTwin = client.GetDigitalTwin<BasicDigitalTwin>(sourceId).Value;
+                eventToClients["data"]["$sourceModel"] = sourceDigitalTwin.Metadata.ModelId;
+            }
 
             log.LogInformation($"New event:\n {eventToClients.ToString()}");
 

adt-event-endpoint-function/digitaltwins-event-endpoint.csproj

@@ -5,6 +5,8 @@
     <RootNamespace>digitaltwins_event_endpoint</RootNamespace>
   </PropertyGroup>
   <ItemGroup>
+    <PackageReference Include="Azure.DigitalTwins.Core" Version="1.4.0" />
+    <PackageReference Include="Azure.Identity" Version="1.8.2" />
     <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.EventGrid" Version="3.2.1" />
     <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.SignalRService" Version="1.9.0" />
     <PackageReference Include="Microsoft.NET.Sdk.Functions" Version="4.1.3" />