Added time interval config for grouping messages

Author: martinmitrevski

Sources/StreamChatSwiftUI/ChatChannel/ChatChannelViewModel.swift

@@ -345,23 +345,34 @@ open class ChatChannelViewModel: ObservableObject, MessagesDataSource {
 
     private func groupMessages() {
         var temp = [String: [String]]()
+        let primary = "primary"
         for (index, message) in messages.enumerated() {
-            let dateString = messagesDateFormatter.string(from: message.createdAt)
-            let prefix = messageCachingUtils.authorId(for: message)
-            let key = "\(prefix)-\(dateString)"
-            if temp[key] == nil {
-                temp[key] = [message.id]
-            } else {
-                // check if the previous message is not sent by the same user.
-                let previousIndex = index - 1
-                if previousIndex >= 0 {
-                    let previous = messages[previousIndex]
-                    let previousAuthorId = messageCachingUtils.authorId(for: previous)
-                    let shouldAddKey = prefix != previousAuthorId
-                    if shouldAddKey {
-                        temp[key]?.append(message.id)
-                    }
-                }
+            let date = message.createdAt
+            if index == 0 {
+                temp[message.id] = [primary]
+                continue
+            }
+
+            let previous = index - 1
+            let previousMessage = messages[previous]
+            let currentAuthorId = messageCachingUtils.authorId(for: message)
+            let previousAuthorId = messageCachingUtils.authorId(for: previousMessage)
+
+            if currentAuthorId != previousAuthorId {
+                temp[message.id] = [primary]
+            }
+
+            if previousMessage.type == .error
+                || previousMessage.type == .ephemeral
+                || previousMessage.type == .system {
+                temp[message.id] = [primary]
+                continue
+            }
+
+            let delay = previousMessage.createdAt.timeIntervalSince(date)
+
+            if delay > utils.messageListConfig.maxTimeIntervalBetweenMessagesInGroup {
+                temp[message.id] = [primary]
             }
         }
 

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageListConfig.swift

@@ -19,7 +19,8 @@ public struct MessageListConfig {
         messagePopoverEnabled: Bool = true,
         doubleTapOverlayEnabled: Bool = false,
         becomesFirstResponderOnOpen: Bool = false,
-        updateChannelsFromMessageList: Bool = false
+        updateChannelsFromMessageList: Bool = false,
+        maxTimeIntervalBetweenMessagesInGroup: TimeInterval = 60
     ) {
         self.messageListType = messageListType
         self.typingIndicatorPlacement = typingIndicatorPlacement
@@ -32,6 +33,7 @@ public struct MessageListConfig {
         self.doubleTapOverlayEnabled = doubleTapOverlayEnabled
         self.becomesFirstResponderOnOpen = becomesFirstResponderOnOpen
         self.updateChannelsFromMessageList = updateChannelsFromMessageList
+        self.maxTimeIntervalBetweenMessagesInGroup = maxTimeIntervalBetweenMessagesInGroup
     }
 
     let messageListType: MessageListType
@@ -45,6 +47,7 @@ public struct MessageListConfig {
     let doubleTapOverlayEnabled: Bool
     let becomesFirstResponderOnOpen: Bool
     let updateChannelsFromMessageList: Bool
+    let maxTimeIntervalBetweenMessagesInGroup: TimeInterval
 }
 
 /// Contains information about the message paddings.

Sources/StreamChatSwiftUI/ChatChannel/MessageList/MessageListView.swift

@@ -231,11 +231,7 @@ public struct MessageListView<Factory: ViewFactory>: View, KeyboardReadable {
         if !messageListConfig.groupMessages {
             return true
         }
-        let dateString = dateFormatter.string(from: message.createdAt)
-        let prefix = utils.messageCachingUtils.authorId(for: message)
-        let key = "\(prefix)-\(dateString)"
-        let inMessagingGroup = messagesGroupingInfo[key]?.contains(message.id) ?? false
-        return inMessagingGroup
+        return messagesGroupingInfo[message.id] != nil
     }
 
     private func handleLongPress(messageDisplayInfo: MessageDisplayInfo) {

StreamChatSwiftUITests/Tests/ChatChannel/ChatChannelViewModel_Tests.swift

@@ -47,7 +47,7 @@ class ChatChannelViewModel_Tests: StreamChatTestCase {
         let messagesGroupingInfo = viewModel.messagesGroupingInfo
 
         // Then
-        XCTAssert(messagesGroupingInfo.count == 8)
+        XCTAssert(messagesGroupingInfo.count == 1)
         for (_, groupingInfo) in messagesGroupingInfo {
             XCTAssert(groupingInfo.count == 1)
         }

docusaurus/docs/iOS/swiftui/components/message-list.md

@@ -191,6 +191,10 @@ The parameters that you can use in this method are:
 - `onLongPress`: called when the message is long pressed.
 - `isLast`: whether it is the last message (e.g. to apply extra padding).
 
+## Grouping Messages
+
+The messages are grouped based on the `maxTimeIntervalBetweenMessagesInGroup` value in the `MessageListConfig`. The default value of this property is 60 seconds, which means messages that are 60 seconds (or less) apart, will be grouped together. You can change this value when you initialize the `MessageListConfig`.
+
 ## System Messages 
 
 If you are using the default implementation of the message container view, you can customize the system messages. These are messages that are not sent by the participants, but they represent some system events (like people added to the channel and similar). In order to change the UI of the system messages, you need to implement the `makeSystemMessageView` in the `ViewFactory` protocol.