fix persistence bugs and update example

packages/stream_chat/lib/src/api/channel.dart

@@ -618,16 +618,26 @@ class Channel {
       }
     }
 
-    final response = await _client.post(path, data: payload);
-    final updatedState = _client.decode(response.data, ChannelState.fromJson);
+    try {
+      final response = await _client.post(path, data: payload);
+      final updatedState = _client.decode(response.data, ChannelState.fromJson);
 
-    if (_id == null) {
-      _id = updatedState.channel.id;
-      _cid = updatedState.channel.cid;
+      if (_id == null) {
+        _id = updatedState.channel.id;
+        _cid = updatedState.channel.cid;
+      }
+
+      state?.updateChannelState(updatedState);
+      return updatedState;
+    } catch (e) {
+      if (!_client.persistenceEnabled) {
+        rethrow;
+      }
+      return _client.chatPersistenceClient?.getChannelStateByCid(
+        cid,
+        messagePagination: messagesPagination,
+      );
     }
-
-    state?.updateChannelState(updatedState);
-    return updatedState;
   }
 
   /// Query channel members

packages/stream_chat/lib/src/db/chat_persistence_client.dart

@@ -173,8 +173,10 @@ abstract class ChatPersistenceClient {
 
     final reactions = channelStates.expand((it) => it.messages).expand((it) {
       return [
-        ...it.ownReactions.where((r) => r.userId != null),
-        ...it.latestReactions.where((r) => r.userId != null)
+        if (it.ownReactions != null)
+          ...it.ownReactions.where((r) => r.userId != null),
+        if (it.latestReactions != null)
+          ...it.latestReactions.where((r) => r.userId != null)
       ];
     }).where((it) => it != null);
 
@@ -184,12 +186,14 @@ abstract class ChatPersistenceClient {
               ...cs.messages?.map((m) {
                 return [
                   m.user,
-                  ...m.latestReactions?.map((r) => r.user),
-                  ...m.ownReactions?.map((r) => r.user),
+                  if (m.latestReactions != null)
+                    ...m.latestReactions.map((r) => r.user),
+                  if (m.ownReactions != null)
+                    ...m.ownReactions.map((r) => r.user),
                 ];
               })?.expand((v) => v),
-              ...cs.read?.map((r) => r.user),
-              ...cs.members?.map((m) => m.user),
+              if (cs.read != null) ...cs.read.map((r) => r.user),
+              if (cs.members != null) ...cs.members.map((m) => m.user),
             ])
         .expand((it) => it)
         .where((it) => it != null);
@@ -202,7 +206,7 @@ abstract class ChatPersistenceClient {
 
     final updateReadsFuture = channelStates.map((it) {
       final cid = it.channel.cid;
-      final reads = it.read.where((it) => it != null);
+      final reads = it.read?.where((it) => it != null) ?? [];
       return updateReads(cid, reads.toList(growable: false));
     }).toList(growable: false);
 

packages/stream_chat_persistence/example/lib/main.dart

@@ -7,6 +7,8 @@ Future<void> main() async {
   /// project dashboard.
   final client = StreamChatClient('b67pax5b2wdq');
 
+  WidgetsFlutterBinding.ensureInitialized();
+
   /// Set the chatPersistenceClient for offline support
   client.chatPersistenceClient = StreamChatPersistenceClient(
     logLevel: Level.INFO,

packages/stream_chat_persistence/lib/src/dao/message_dao.dart

@@ -3,6 +3,7 @@ import 'package:stream_chat/stream_chat.dart';
 import 'package:stream_chat_persistence/src/db/moor_chat_database.dart';
 import 'package:stream_chat_persistence/src/entity/messages.dart';
 import 'package:stream_chat_persistence/src/entity/users.dart';
+
 import '../mapper/mapper.dart';
 
 part 'message_dao.g.dart';
@@ -136,7 +137,11 @@ class MessageDao extends DatabaseAccessor<MoorChatDatabase>
 
   /// Updates the message data of a particular channel with
   /// the new [messageList] data
-  Future<void> updateMessages(String cid, List<Message> messageList) {
+  Future<void> updateMessages(String cid, List<Message> messageList) async {
+    if (messageList == null) {
+      return;
+    }
+
     return batch((batch) {
       batch.insertAll(
         messages,

packages/stream_chat_persistence/lib/src/mapper/message_mapper.dart

@@ -47,7 +47,7 @@ extension MessageX on Message {
   MessageEntity toEntity({String cid}) {
     return MessageEntity(
       id: id,
-      attachments: attachments.map((it) => jsonEncode(it)).toList(),
+      attachments: attachments?.map((it) => jsonEncode(it))?.toList() ?? [],
       channelCid: cid,
       type: type,
       parentId: parentId,