feat(llc): add pending messages for channels

packages/stream_chat/CHANGELOG.md

@@ -8,6 +8,8 @@
 ✅ Added
 
 - Added support for `Channel.messageCount` field.
+- Added support for Pending Messages. Pending messages can be accessed via
+  `ChannelState.pendingMessages` or `ChannelState.pendingMessagesStream`.
 
 🐞 Fixed
 

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

@@ -3152,6 +3152,15 @@ class ChannelClientState {
       .map((cs) => cs.pinnedMessages ?? <Message>[])
       .distinct(const ListEquality().equals);
 
+  /// Channel pending message list.
+  List<Message> get pendingMessages =>
+      _channelState.pendingMessages ?? <Message>[];
+
+  /// Channel pending message list as a stream.
+  Stream<List<Message>> get pendingMessagesStream => channelStateStream
+      .map((cs) => cs.pendingMessages ?? <Message>[])
+      .distinct(const ListEquality().equals);
+
   /// Get channel last message.
   Message? get lastMessage =>
       _channelState.messages != null && _channelState.messages!.isNotEmpty
@@ -3376,6 +3385,7 @@ class ChannelClientState {
       read: newReads,
       draft: updatedState.draft,
       pinnedMessages: updatedState.pinnedMessages,
+      pendingMessages: updatedState.pendingMessages,
       pushPreferences: updatedState.pushPreferences,
     );
   }

packages/stream_chat/lib/src/core/models/channel_config.dart

@@ -26,6 +26,7 @@ class ChannelConfig {
     this.urlEnrichment = false,
     this.skipLastMsgUpdateForSystemMsgs = false,
     this.userMessageReminders = false,
+    this.markMessagesPending = false,
   })  : createdAt = createdAt ?? DateTime.now(),
         updatedAt = updatedAt ?? DateTime.now();
 
@@ -91,6 +92,9 @@ class ChannelConfig {
   /// True if the user can set reminders for messages in this channel.
   final bool userMessageReminders;
 
+  /// Whether pending messages are enabled for this channel.
+  final bool markMessagesPending;
+
   /// Serialize to json
   Map<String, dynamic> toJson() => _$ChannelConfigToJson(this);
 }

packages/stream_chat/lib/src/core/models/channel_state.dart

@@ -30,6 +30,7 @@ class ChannelState implements ComparableFieldProvider {
     this.read,
     this.membership,
     this.draft,
+    this.pendingMessages,
     this.pushPreferences,
   });
 
@@ -60,6 +61,28 @@ class ChannelState implements ComparableFieldProvider {
   /// The draft message for this channel if it exists.
   final Draft? draft;
 
+  static Object? _pendingMessagesReadValue(
+    Map<Object?, Object?> json,
+    String key,
+  ) {
+    final pendingMessageResponse = json[key];
+    if (pendingMessageResponse is! List<Object?>) return null;
+
+    final value = pendingMessageResponse.map((it) {
+      if (it is! Map<String, Object?>) return null;
+      return it['message'];
+    }).nonNulls;
+
+    if (value.isEmpty) return null;
+    return value.toList(growable: false);
+  }
+
+  /// List of messages pending for moderation on this channel.
+  ///
+  /// These messages are only visible to the author until they are approved.
+  @JsonKey(readValue: _pendingMessagesReadValue)
+  final List<Message>? pendingMessages;
+
   /// The push preferences for this channel if it exists.
   final ChannelPushPreference? pushPreferences;
 
@@ -81,6 +104,7 @@ class ChannelState implements ComparableFieldProvider {
     List<Read>? read,
     Member? membership,
     Object? draft = _nullConst,
+    List<Message>? pendingMessages,
     ChannelPushPreference? pushPreferences,
   }) =>
       ChannelState(
@@ -93,6 +117,7 @@ class ChannelState implements ComparableFieldProvider {
         read: read ?? this.read,
         membership: membership ?? this.membership,
         draft: draft == _nullConst ? this.draft : draft as Draft?,
+        pendingMessages: pendingMessages ?? this.pendingMessages,
         pushPreferences: pushPreferences ?? this.pushPreferences,
       );
 

packages/stream_chat/test/fixtures/channel_state_to_json.json

@@ -12,6 +12,7 @@
   "read": [],
   "membership": null,
   "draft": null,
+  "pending_messages": null,
   "push_preferences": {
     "chat_level": "all",
     "disabled_until": "2020-01-30T13:43:41.062362Z"