Change Component to ContentPublishedNotificationHandler

Author: erikjanwestendorp

14/umbraco-cms/reference/management/using-services/relationservice.md

@@ -6,78 +6,56 @@ Below you will find examples using `RelationService`.
 
 ## Automatically relate to root node
 
-To perform the said task we need a component in which we can register to the `ContentService.Published` event:
+To perform the said task we need a Notification Handler:
 
 [You can read more about composing Umbraco here](../../../implementation/composing.md)
 
 ```csharp
-using System.Linq;
-using Umbraco.Core.Composing;
-using Umbraco.Core.Events;
-using Umbraco.Core.Services;
-using Umbraco.Core.Services.Implement;
+using Umbraco.Cms.Core.Events;
+using Umbraco.Cms.Core.Notifications;
+using Umbraco.Cms.Core.Services;
 
 namespace Doccers.Core.Components;
 
-public class RelationComponent : IComponent
+public class ContentPublishedNotificationHandler(IContentService contentService, IRelationService relationService) : INotificationHandler<ContentPublishedNotification>
 {
-    private readonly IRelationService _relationService;
-
-    public RelationComponent(IRelationService relationService)
-    {
-        _relationService = relationService;
-    }
-
-    public void Initialize()
-    {
-        ContentService.Published += ContentService_Published;
-    }
-
-    private void ContentService_Published(IContentService sender,
-        ContentPublishedEventArgs e)
+    public void Handle(ContentPublishedNotification notification)
     {
-        // Should never be null, to be honest.
-        var home = sender.GetRootContent()?.FirstOrDefault();
+        var home = contentService.GetRootContent().FirstOrDefault();
         if (home == null) return;
 
         // Get the relation type by alias
-        var relationType = _relationService.GetRelationTypeByAlias("homesick");
+        var relationType = relationService.GetRelationTypeByAlias("homesick");
+
         if (relationType == null) return;
 
-        foreach (var entity in e.PublishedEntities
-            .Where(x => x.Id != home.Id))
+        foreach (var entity in notification.PublishedEntities
+                     .Where(x => x.Id != home.Id))
         {
             // Check if they are already related
-            if (!_relationService.AreRelated(home.Id, entity.Id))
+            if (!relationService.AreRelated(home.Id, entity.Id))
             {
                 // If not then let us relate the currenty entity to home
-                _relationService.Relate(home.Id, entity.Id, relationType);
+                relationService.Relate(home.Id, entity.Id, relationType);
             }
         }
     }
-
-    public void Terminate() {
-        //unsubscribe during shutdown
-        ContentService.Published -= ContentService_Published;
-    }
 }
 ```
 
-To have Umbraco recognize our component we need to register it in a composer:
+To have Umbraco recognize our Notification Handler we need to register it in a composer:
 
 ```csharp
-using Doccers.Core.Components;
-using Umbraco.Core;
-using Umbraco.Core.Composing;
+using Umbraco.Cms.Core.Composing;
+using Umbraco.Cms.Core.Notifications;
 
 namespace Doccers.Core.Composers;
 
-[RuntimeLevel(MinLevel = RuntimeLevel.Run)]
-public class RelationComposer : IUserComposer
+public class RelationComposer : IComposer
 {
-    public void Compose(Composition composition)
+    public void Compose(IUmbracoBuilder builder)
     {
-        composition.Components().Append<RelationComponent>();
+        builder.AddNotificationHandler<ContentPublishedNotification, ContentPublishedNotificationHandler>();
     }
 }
 ```