Show error messages on the custom post types screens

Author: crazytonyli

WordPress/Classes/ViewRelated/CustomPostTypes/CustomPostListView.swift

@@ -27,6 +27,8 @@ struct CustomPostListView: View {
                 EmptyStateView(emptyText, systemImage: "doc.text")
             } else if viewModel.shouldDisplayInitialLoading {
                 ProgressView()
+            } else if let error = viewModel.errorToDisplay() {
+                EmptyStateView.failure(error: error)
             }
         }
         .refreshable {
@@ -58,7 +60,10 @@ private struct PaginatedList: View {
                     }
             }
 
-            makeFooterView()
+            Section {
+                makeFooterView()
+            }
+            .listSectionSeparator(.hidden)
         }
         .listStyle(.plain)
     }
@@ -80,6 +85,7 @@ private struct PaginatedList: View {
         do {
             try await onLoadNextPage()
         } catch {
+            DDLogError("Failed to load next page: \(error)")
             self.loadMoreError = error
         }
     }
@@ -91,15 +97,16 @@ private struct PaginatedList: View {
                 .progressViewStyle(.circular)
                 .frame(maxWidth: .infinity, minHeight: 44, alignment: .center)
                 .id(UUID()) // A hack to show the ProgressView after cell reusing.
-        } else if loadMoreError != nil {
-            Button {
-                Task { await loadNextPage() }
-            } label: {
-                HStack {
-                    Image(systemName: "exclamationmark.circle")
-                    Text(SharedStrings.Button.retry)
+        } else if let loadMoreError {
+            VStack {
+                Text(verbatim: loadMoreError.localizedDescription)
+                Button {
+                    Task { await loadNextPage() }
+                } label: {
+                    Text(verbatim: SharedStrings.Button.retry)
                 }
-            }
+                .buttonStyle(.borderedProminent)
+            }.frame(maxWidth: .infinity, alignment: .center)
         }
     }
 }
@@ -291,3 +298,20 @@ private enum Strings {
         onSelectPost: { _ in }
     )
 }
+
+#Preview("Load Next Page Error") {
+    PaginatedList(
+        items: [
+            .stale(
+                id: 1,
+                post: CustomPostCollectionDisplayPost(
+                    date: .now,
+                    title: "Published Post",
+                    excerpt: "This post has stale data and is being refreshed."
+                )
+            ),
+        ],
+        onLoadNextPage: { throw CollectionError.DatabaseError(errMessage: "SQL error") },
+        onSelectPost: { _ in },
+    )
+}

WordPress/Classes/ViewRelated/CustomPostTypes/CustomPostListViewModel.swift

@@ -16,6 +16,7 @@ final class CustomPostListViewModel: ObservableObject {
 
     @Published private(set) var items: [CustomPostCollectionItem] = []
     @Published private(set) var listInfo: ListInfo?
+    @Published private var error: Error?
 
     var shouldDisplayEmptyView: Bool {
         items.isEmpty && listInfo?.isSyncing == false
@@ -25,6 +26,10 @@ final class CustomPostListViewModel: ObservableObject {
         items.isEmpty && listInfo?.isSyncing == true
     }
 
+    func errorToDisplay() -> Error? {
+        items.isEmpty ? error : nil
+    }
+
     init(
         client: WordPressClient,
         service: WpSelfHostedService,
@@ -49,7 +54,8 @@ final class CustomPostListViewModel: ObservableObject {
         do {
             _ = try await collection?.refresh()
         } catch {
-            DDLogError("Pull to refresh failed: \(error)")
+            DDLogError("Failed to refresh posts: \(error)")
+            self.show(error: error)
         }
     }
 
@@ -95,6 +101,15 @@ final class CustomPostListViewModel: ObservableObject {
             }
         }
     }
+
+    private func show(error: Error) {
+        self.error = error
+
+        if !items.isEmpty {
+            // Show an error notice, on top of the list content.
+            Notice(error: error).post()
+        }
+    }
 }
 
 struct CustomPostCollectionDisplayPost: Equatable {

WordPress/Classes/ViewRelated/CustomPostTypes/CustomPostTypesView.swift

@@ -63,7 +63,12 @@ struct CustomPostTypesView: View {
                 _ = try await self.collection.fetch()
                 await refresh()
             } catch {
-                self.error = error
+                DDLogError("Failed to query stored post types: \(error)")
+                if types.isEmpty {
+                    self.error = error
+                } else {
+                    Notice(error: error).post()
+                }
             }
         }
     }
@@ -83,6 +88,7 @@ struct CustomPostTypesView: View {
                     $0.1.slug < $1.1.slug
                 }
         } catch {
+            DDLogError("Failed to fetch post types: \(error)")
             self.error = error
         }
     }