Refactor comment view models.

src/GitHub.App/SampleData/CommentThreadViewModelDesigner.cs

@@ -1,23 +1,21 @@
-using System;
-using System.Collections.ObjectModel;
-using System.Diagnostics.CodeAnalysis;
-using System.Reactive;
+using System.Diagnostics.CodeAnalysis;
+using System.Threading.Tasks;
 using GitHub.ViewModels;
 using ReactiveUI;
 
 namespace GitHub.SampleData
 {
     [SuppressMessage("Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses")]
-    public class CommentThreadViewModelDesigner : ICommentThreadViewModel
+    public class CommentThreadViewModelDesigner : ViewModelBase, ICommentThreadViewModel
     {
-        public ObservableCollection<ICommentViewModel> Comments { get; }
-            = new ObservableCollection<ICommentViewModel>();
+        public IReadOnlyReactiveList<ICommentViewModel> Comments { get; }
+            = new ReactiveList<ICommentViewModel>();
 
         public IActorViewModel CurrentUser { get; set; }
             = new ActorViewModel { Login = "shana" };
 
-        public ReactiveCommand<string, Unit> PostComment { get; }
-        public ReactiveCommand<Tuple<string, string>, Unit> EditComment { get; }
-        public ReactiveCommand<Tuple<int, int>, Unit> DeleteComment { get; }
+        public Task DeleteComment(int pullRequestId, int commentId) => Task.CompletedTask;
+        public Task EditComment(string id, string body) => Task.CompletedTask;
+        public Task PostComment(string body) => Task.CompletedTask;
     }
 }

src/GitHub.App/SampleData/CommentViewModelDesigner.cs

@@ -24,7 +24,7 @@ public CommentViewModelDesigner()
         public bool IsSubmitting { get; set; }
         public bool CanDelete { get; } = true;
         public ICommentThreadViewModel Thread { get; }
-        public DateTimeOffset UpdatedAt => DateTime.Now.Subtract(TimeSpan.FromDays(3));
+        public DateTimeOffset CreatedAt => DateTime.Now.Subtract(TimeSpan.FromDays(3));
         public IActorViewModel Author { get; set; }
         public Uri WebUrl { get; }
 

src/GitHub.App/ViewModels/CommentThreadViewModel.cs

@@ -1,77 +1,53 @@
-using System;
-using System.Collections.ObjectModel;
-using System.Reactive;
+using System.ComponentModel.Composition;
+using System.Threading.Tasks;
 using GitHub.Extensions;
 using GitHub.Models;
-using GitHub.ViewModels;
 using ReactiveUI;
 
-namespace GitHub.InlineReviews.ViewModels
+namespace GitHub.ViewModels
 {
     /// <summary>
     /// Base view model for a thread of comments.
     /// </summary>
     public abstract class CommentThreadViewModel : ReactiveObject, ICommentThreadViewModel
     {
-        ReactiveCommand<string, Unit> postComment;
-        ReactiveCommand<Tuple<string, string>, Unit> editComment;
-        ReactiveCommand<Tuple<int, int>, Unit> deleteComment;
+        readonly ReactiveList<ICommentViewModel> comments = new ReactiveList<ICommentViewModel>();
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CommentThreadViewModel"/> class.
+        /// </summary>
+        [ImportingConstructor]
+        public CommentThreadViewModel()
+        {
+        }
 
         /// <summary>
         /// Intializes a new instance of the <see cref="CommentThreadViewModel"/> class.
         /// </summary>
         /// <param name="currentUser">The current user.</param>
-        protected CommentThreadViewModel(ActorModel currentUser)
+        protected Task InitializeAsync(ActorModel currentUser)
         {
             Guard.ArgumentNotNull(currentUser, nameof(currentUser));
-
-            Comments = new ObservableCollection<ICommentViewModel>();
             CurrentUser = new ActorViewModel(currentUser);
+            return Task.CompletedTask;
         }
 
         /// <inheritdoc/>
-        public ObservableCollection<ICommentViewModel> Comments { get; }
+        public IReactiveList<ICommentViewModel> Comments => comments;
 
         /// <inheritdoc/>
-        public ReactiveCommand<string, Unit> PostComment
-        {
-            get { return postComment; }
-            protected set
-            {
-                Guard.ArgumentNotNull(value, nameof(value));
-                postComment = value;
-
-                // We want to ignore thrown exceptions from PostComment - the error should be handled
-                // by the CommentViewModel that trigged PostComment.Execute();
-                value.ThrownExceptions.Subscribe(_ => { });
-            }
-        }
+        public IActorViewModel CurrentUser { get; private set; }
 
-        public ReactiveCommand<Tuple<string, string>, Unit> EditComment
-        {
-            get { return editComment; }
-            protected set
-            {
-                Guard.ArgumentNotNull(value, nameof(value));
-                editComment = value;
-
-                value.ThrownExceptions.Subscribe(_ => { });
-            }
-        }
+        /// <inheritdoc/>
+        IReadOnlyReactiveList<ICommentViewModel> ICommentThreadViewModel.Comments => comments;
 
-        public ReactiveCommand<Tuple<int, int>, Unit> DeleteComment
-        {
-            get { return deleteComment; }
-            protected set
-            {
-                Guard.ArgumentNotNull(value, nameof(value));
-                deleteComment = value;
+        /// <inheritdoc/>
+        public abstract Task PostComment(string body);
 
-                value.ThrownExceptions.Subscribe(_ => { });
-            }
-        }
+        /// <inheritdoc/>
+        public abstract Task EditComment(string id, string body);
 
         /// <inheritdoc/>
-        public IActorViewModel CurrentUser { get; }
+        public abstract Task DeleteComment(int pullRequestId, int commentId);
     }
 }