Notification Comment details: show loading and error views

WordPress/Classes/ViewRelated/Comments/CommentDetailViewController.swift

@@ -11,7 +11,7 @@ let userInfoCommentIdKey = "commentID"
     func nextCommentSelected()
 }
 
-class CommentDetailViewController: UIViewController {
+class CommentDetailViewController: UIViewController, NoResultsViewHost {
 
     // MARK: Properties
 
@@ -247,10 +247,21 @@ class CommentDetailViewController: UIViewController {
 
     // Update the Notification Comment being displayed.
     func refreshView(comment: Comment, notification: Notification) {
+        hideNoResults()
         self.notification = notification
         displayComment(comment)
     }
 
+    // Show an empty view with the given values.
+    func showNoResultsView(title: String, subtitle: String? = nil, imageName: String? = nil, accessoryView: UIView? = nil) {
+        hideNoResults()
+        configureAndDisplayNoResults(on: tableView,
+                                     title: title,
+                                     subtitle: subtitle,
+                                     image: imageName,
+                                     accessoryView: accessoryView)
+    }
+
 }
 
 // MARK: - Private Helpers

WordPress/Classes/ViewRelated/Notifications/Controllers/NotificationCommentDetailViewController.swift

@@ -1,6 +1,6 @@
 import UIKit
 
-class NotificationCommentDetailViewController: UIViewController {
+class NotificationCommentDetailViewController: UIViewController, NoResultsViewHost {
 
     // MARK: - Properties
 
@@ -159,6 +159,8 @@ private extension NotificationCommentDetailViewController {
     }
 
     func loadComment() {
+        showLoadingView()
+
         fetchParentCommentIfNeeded(completion: { [weak self] in
             guard let self = self else {
                 return
@@ -169,13 +171,13 @@ private extension NotificationCommentDetailViewController {
                 return
             }
 
-            self.fetchComment(self.commentID, completion: { comment in
+            self.fetchComment(self.commentID, completion: { [weak self] comment in
                 guard let comment = comment else {
-                    // TODO: show error view
+                    self?.showErrorView()
                     return
                 }
 
-                self.comment = comment
+                self?.comment = comment
             })
         })
     }
@@ -184,7 +186,6 @@ private extension NotificationCommentDetailViewController {
         guard let commentID = commentID,
               let blog = blog else {
                   DDLogError("Notification Comment: unable to load comment due to missing information.")
-                  // TODO: show error view
                   return nil
               }
 
@@ -195,15 +196,13 @@ private extension NotificationCommentDetailViewController {
         guard let commentID = commentID,
               let blog = blog else {
                   DDLogError("Notification Comment: unable to fetch comment due to missing information.")
-                  // TODO: show error view
                   completion(nil)
                   return
               }
 
         commentService.loadComment(withID: commentID, for: blog, success: { comment in
             completion(comment)
         }, failure: { error in
-            // TODO: show error view
             completion(nil)
         })
     }
@@ -226,4 +225,41 @@ private extension NotificationCommentDetailViewController {
         static let arrowButtonSpacing: CGFloat = 12
     }
 
+    // MARK: - No Results Views
+
+    func showLoadingView() {
+        if let commentDetailViewController = commentDetailViewController {
+            commentDetailViewController.showNoResultsView(title: NoResults.loadingTitle,
+                                                          accessoryView: NoResultsViewController.loadingAccessoryView())
+        } else {
+            hideNoResults()
+            configureAndDisplayNoResults(on: view,
+                                         title: NoResults.loadingTitle,
+                                         accessoryView: NoResultsViewController.loadingAccessoryView())
+        }
+    }
+
+    func showErrorView() {
+        if let commentDetailViewController = commentDetailViewController {
+            commentDetailViewController.showNoResultsView(title: NoResults.errorTitle,
+                                                          subtitle: NoResults.errorSubtitle,
+                                                          imageName: NoResults.imageName)
+        } else {
+            hideNoResults()
+            configureAndDisplayNoResults(on: view,
+                                         title: NoResults.errorTitle,
+                                         subtitle: NoResults.errorSubtitle,
+                                         image: NoResults.imageName)
+
+
+        }
+    }
+
+    struct NoResults {
+        static let loadingTitle = NSLocalizedString("Loading comment...", comment: "Displayed while a comment is being loaded.")
+        static let errorTitle = NSLocalizedString("Oops", comment: "Title for the view when there's an error loading a comment.")
+        static let errorSubtitle = NSLocalizedString("There was an error loading the comment.", comment: "Text displayed when there is a failure loading a comment.")
+        static let imageName = "wp-illustration-notifications"
+    }
+
 }