Improve error handling in message view

lib/clients/api_client.dart

@@ -124,10 +124,13 @@ class ApiClient {
     if (response.statusCode == 403) {
       tryCachedLogin();
       // TODO: Show the login screen again if cached login was unsuccessful.
-      throw "You are not authorized to do that.";
+      throw "You are not authorized to do that";
+    }
+    if (response.statusCode == 500) {
+      throw "Internal server error";
     }
     if (response.statusCode != 200) {
-      throw "Unknown Error${kDebugMode ? ": ${response.statusCode}|${response.body}" : ""}";
+      throw "Unknown Error: ${response.statusCode}${kDebugMode ? "|${response.body}" : ""}";
     }
   }
 

lib/clients/messaging_client.dart

@@ -196,6 +196,10 @@ class MessagingClient extends ChangeNotifier {
 
   MessageCache _createUserMessageCache(String userId) => MessageCache(apiClient: _apiClient, userId: userId);
 
+  void deleteUserMessageCache(String userId) {
+    _messageCache.remove(userId);
+  }
+
   Future<void> loadUserMessageCache(String userId) async {
     final cache = getUserMessageCache(userId) ?? _createUserMessageCache(userId);
     await cache.loadMessages();

lib/models/message.dart

@@ -114,7 +114,7 @@ class MessageCache {
   final List<Message> _messages = [];
   final ApiClient _apiClient;
   final String _userId;
-  Future? currentOperation;
+  Object? error;
 
   List<Message> get messages => _messages;
 
@@ -155,9 +155,14 @@ class MessageCache {
   }
 
   Future<void> loadMessages() async {
+    error = null;
+    try {
       final messages = await MessageApi.getUserMessages(_apiClient, userId: _userId);
       _messages.addAll(messages);
       _ensureIntegrity();
+    } catch (e) {
+      error = e;
+    }
   }
 
   void _ensureIntegrity() {

lib/widgets/messages/messages_list.dart

@@ -2,6 +2,7 @@ import 'package:contacts_plus_plus/client_holder.dart';
 import 'package:contacts_plus_plus/clients/messaging_client.dart';
 import 'package:contacts_plus_plus/models/friend.dart';
 import 'package:contacts_plus_plus/models/message.dart';
+import 'package:contacts_plus_plus/widgets/default_error_widget.dart';
 import 'package:contacts_plus_plus/widgets/friends/friend_online_status_indicator.dart';
 import 'package:contacts_plus_plus/widgets/messages/messages_session_header.dart';
 import 'package:flutter/material.dart';
@@ -78,6 +79,9 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
         .of(context)
         .colorScheme
         .surfaceVariant;
+    return Consumer<MessagingClient>(
+      builder: (context, mClient, _) {
+        final cache = mClient.getUserMessageCache(widget.friend.id);
         return Scaffold(
           appBar: AppBar(
             title: Row(
@@ -143,9 +147,8 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
                 ),
               ),
               Expanded(
-            child: Consumer<MessagingClient>(
-              builder: (context, mClient, _) {
-                final cache = mClient.getUserMessageCache(widget.friend.id);
+                child: Builder(
+                  builder: (context) {
                     if (cache == null) {
                         return const Column(
                           mainAxisAlignment: MainAxisAlignment.start,
@@ -154,6 +157,17 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
                           ],
                         );
                     }
+                    if (cache.error != null) {
+                      return DefaultErrorWidget(
+                        message: cache.error.toString(),
+                        onRetry: () {
+                          setState(() {
+                            mClient.deleteUserMessageCache(widget.friend.id);
+                          });
+                          mClient.loadUserMessageCache(widget.friend.id);
+                        },
+                      );
+                    }
                     if (cache.messages.isEmpty) {
                       return Center(
                         child: Column(
@@ -212,6 +226,7 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
                       child: Padding(
                         padding: const EdgeInsets.all(8),
                         child: TextField(
+                          enabled: cache != null && cache.error == null,
                           autocorrect: true,
                           controller: _messageTextController,
                           maxLines: 4,
@@ -229,8 +244,9 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
                           },
                           decoration: InputDecoration(
                               isDense: true,
-                          hintText: "Send a message to ${widget.friend
+                              hintText: "Message ${widget.friend
                                   .username}...",
+                              hintMaxLines: 1,
                               contentPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
                               border: OutlineInputBorder(
                                   borderRadius: BorderRadius.circular(24)
@@ -287,4 +303,6 @@ class _MessagesListState extends State<MessagesList> with SingleTickerProviderSt
           ),
         );
       }
+    );
+  }
 }

pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.2.1+1
+version: 1.2.2+1
 
 environment:
   sdk: '>=3.0.0'