Delete topics and comments

You can use the Annotations package to delete existing topics and comments.

Delete an existing topic

To delete an existing topic, follow these steps:

1. Open the AnnotationBehaviour script you created in Get started.

2. Paste the following code sample into your script:

   using System;
   using System.Linq;
   using System.Threading.Tasks;
   using Unity.Cloud.Annotation;
   using Unity.Cloud.Annotation.Runtime;
   using Unity.Cloud.Common;
   using Unity.Cloud.Identity;
   using UnityEngine;
   
   public class AnnotationBehaviour : MonoBehaviour
   {
       // The annotation repository retrieves, creates, edits, and removes annotations from a scene
       IAnnotationRepository m_AnnotationRepository;
   
       // The id for the scene to initialize the annotation repository with
       static readonly SceneId k_SceneId = new("<enter-id-here>");
   
       // The authenticator responsible for user login
       ICompositeAuthenticator m_CompositeAuthenticator;
       bool m_HasAttemptedLogin;
   
       async Task Start()
       {
           // Register to get notified of the login state after the authenticator has initialized
           m_CompositeAuthenticator = PlatformServices.CompositeAuthenticator;
           m_CompositeAuthenticator.AuthenticationStateChanged += ApplyAuthenticationState;
   
           // Apply the initial state for the authenticator
           ApplyAuthenticationState(m_CompositeAuthenticator.AuthenticationState);
       }
   
       void ApplyAuthenticationState(AuthenticationState newAuthenticationState)
       {
           switch (newAuthenticationState)
           {
               case AuthenticationState.LoggedIn:
                   // If the user is logged in, initialize the repository
                   m_CompositeAuthenticator.AuthenticationStateChanged -= ApplyAuthenticationState;
                   _ = InitializeAnnotationRepository();
                   break;
               case AuthenticationState.LoggedOut:
                   // If the user is logged out, attempt to automatically login
                   // Set a flag to ensure we only attempt an auto-login once
                   if (!m_HasAttemptedLogin)
                   {
                       m_HasAttemptedLogin = true;
                       _ = m_CompositeAuthenticator.LoginAsync();
                   }
                   else
                   {
                       // Unregister if login attempt failed
                       m_CompositeAuthenticator.AuthenticationStateChanged -= ApplyAuthenticationState;
                   }
                   break;
           }
       }
   
       async Task InitializeAnnotationRepository()
       {
           // Gets a scene
           var scene = await PlatformServices.SceneProvider.GetSceneAsync(k_SceneId);
   
           // Create a new AnnotationRepository with the chosen scene
           m_AnnotationRepository = new AnnotationRepository(scene, PlatformServices.ServiceHttpClient, PlatformServices.ServiceHostResolver);
   
           await RunExamples();
       }
   
       async Task RunExamples()
       {
           await DeleteTopicExample();
           await DeleteCommentExample();
   
           // Logs you out after running the examples
           if (PlatformServices.CompositeAuthenticator.RequiresGUI)
               await PlatformServices.CompositeAuthenticator.LogoutAsync();
       }
   
       // Create a topic with a specific title
       async Task<ITopic> CreateTopic(string title)
       {
           // Creates a TopicCreation request object using a TopicCreationBuilder and populates it with the necessary fields
           var topicCreationBuilder = new TopicCreationBuilder();
           topicCreationBuilder.SetTitle(title);
   
           // Creates and retrieves the new topic
           var createdTopic = await m_AnnotationRepository.CreateTopicAsync(topicCreationBuilder.GetTopicCreation());
   
           // Returns the new topic
           return createdTopic;
       }
   
       // Create then delete a topic
       async Task DeleteTopicExample()
       {
           // Creates and outputs a topic
           var createdTopic = await CreateTopic("Topic to Delete");
           Debug.Log($"Created Topic ID: {createdTopic.Id}, Created Topic Title: {createdTopic.Title}");
   
           // Deletes the topic and outputs information
           await m_AnnotationRepository.DeleteTopicAsync(createdTopic.Id);
           Debug.Log($"Deleted Topic ID: {createdTopic.Id}");
       }
   
       // Comment on a specific topic with a comment
       async Task<IComment> CreateComment(ITopic parentTopic, string comment)
       {
           // Creates a CommentCreation request object using a CommentCreationBuilder and populates it with the necessary fields
           var commentCreationBuilder = new CommentCreationBuilder();
           commentCreationBuilder.SetText(comment);
   
           // Creates and retrieves the new comment
           var createdComment = await parentTopic.CreateCommentAsync(commentCreationBuilder.GetCommentCreation());
   
           // Returns the new comment
           return createdComment;
       }
   
       // Create a topic with a comment, then delete the comment
       async Task DeleteCommentExample()
       {
           // Creates and outputs a topic
           var parentTopic = await CreateTopic("Parent Topic");
           Debug.Log($"Parent Topic ID: {parentTopic.Id}, Parent Topic Title: {parentTopic.Title}");
   
           // Creates and outputs a comment on the parent topic
           var createdComment = await CreateComment(parentTopic, "A comment to delete");
           Debug.Log($"Created Comment ID: {createdComment.Id}, Created Comment Title: {createdComment.Text}");
   
           // Deletes the comment and outputs information
           await parentTopic.DeleteCommentAsync(createdComment.Id);
           Debug.Log($"Deleted Comment ID: {createdComment.Id}");
       }
   }
   

3. Check your console to confirm that you have successfully deleted the topic.