Merge pull request #18515 from wordpress-mobile/feature/18502-list_empty_view

Blogging Prompts List: add the ability to show empty views for different scenarios.

Author: ScoutHarris

WordPress/Classes/ViewRelated/Blog/Blogging Prompts/BloggingPromptsViewController.swift

@@ -1,7 +1,7 @@
 import UIKit
 
 
-class BloggingPromptsViewController: UIViewController {
+class BloggingPromptsViewController: UIViewController, NoResultsViewHost {
 
     // MARK: - Properties
 
@@ -10,6 +10,11 @@ class BloggingPromptsViewController: UIViewController {
 
     private var blog: Blog?
 
+    // TODO: remove when prompts are fetched, use fetched prompts count.
+    private var promptCount: Int = 10
+    // TODO: set when prompt fetching is added.
+    private var isLoading: Bool = false
+
     // MARK: - Init
 
     class func controllerWithBlog(_ blog: Blog) -> BloggingPromptsViewController {
@@ -30,6 +35,7 @@ class BloggingPromptsViewController: UIViewController {
         title = Strings.viewTitle
         configureFilterTabBar()
         configureTableView()
+        showNoResultsViewIfNeeded()
     }
 
 }
@@ -47,10 +53,54 @@ private extension BloggingPromptsViewController {
         WPStyleGuide.configureColors(view: view, tableView: tableView)
     }
 
+    func showNoResultsViewIfNeeded() {
+        hideNoResults()
+
+        guard !isLoading else {
+            showLoadingView()
+            return
+        }
+
+        // TODO: use fetched prompts count.
+        guard promptCount == 0 else {
+            return
+        }
+
+        showNoResultsView()
+    }
+
+    func showNoResultsView() {
+        configureAndDisplayNoResults(on: tableView,
+                                     title: NoResults.emptyTitle,
+                                     image: NoResults.imageName)
+    }
+
+    func showLoadingView() {
+        configureAndDisplayNoResults(on: tableView,
+                                     title: NoResults.loadingTitle,
+                                     accessoryView: NoResultsViewController.loadingAccessoryView())
+    }
+
+    func showErrorView() {
+        hideNoResults()
+        configureAndDisplayNoResults(on: tableView,
+                                     title: NoResults.errorTitle,
+                                     subtitle: NoResults.errorSubtitle,
+                                     image: NoResults.imageName)
+    }
+
     enum Strings {
         static let viewTitle = NSLocalizedString("Prompts", comment: "View title for Blogging Prompts list.")
     }
 
+    enum NoResults {
+        static let loadingTitle = NSLocalizedString("Loading prompts...", comment: "Displayed while blogging prompts are being loaded.")
+        static let errorTitle = NSLocalizedString("Oops", comment: "Title for the view when there's an error loading blogging prompts.")
+        static let errorSubtitle = NSLocalizedString("There was an error loading prompts.", comment: "Text displayed when there is a failure loading blogging prompts.")
+        static let emptyTitle = NSLocalizedString("No prompts yet", comment: "Title displayed when there are no blogging prompts to display.")
+        static let imageName = "wp-illustration-empty-results"
+    }
+
 }
 
 // MARK: - Table Methods
@@ -59,7 +109,7 @@ extension BloggingPromptsViewController: UITableViewDataSource, UITableViewDeleg
 
     func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         // TODO: use fetched prompts count.
-        return 10
+        return promptCount
     }
 
     func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
@@ -102,6 +152,7 @@ private extension BloggingPromptsViewController {
         // TODO:
         // - track selected filter changed
         // - refresh view for selected filter
+        showNoResultsViewIfNeeded()
     }
 
 }