Threaded Messages

Add threaded reply views to your iOS chat app

Enhance your iOS chat app with threaded messaging by integrating CometChat’s UIKit for iOS, allowing users to reply to specific messages within a focused thread view.

Overview

Threaded messages allow users to reply to specific messages within a conversation, creating a sub-conversation for improved clarity and context. With CometChat’s UIKit for iOS, you can:

• Display a dedicated thread view
• View and send replies to a selected message
• Maintain context between the main conversation and the thread

Prerequisites

Before implementing this feature, ensure you have:

1. Completed Getting Started setup
2. CometChat UIKit v5+ installed
3. User logged in with CometChatUIKit.login()

Components

Component	Description
CometChatMessageList	Displays messages and provides onThreadRepliesClick handler
CometChatThreadedMessageHeader	Shows the parent message context at the top of the thread
CometChatMessageComposer	Composes messages with an optional parentMessageId
ThreadedMessagesVC	View controller that hosts the threaded conversation

Integration Steps

Step 1: Show the “Reply in Thread” Option

Navigate to the thread when a message’s thread icon is tapped:

import UIKit
import CometChatUIKitSwift
import CometChatSDK

class MessagesViewController: UIViewController {
    
    var messageListView: CometChatMessageList!
    
    func setupThreadReplies() {
        // Handle thread replies click
        messageListView.set(onThreadRepliesClick: { [weak self] message, _ in
            guard let self = self else { return }
            
            // Create and configure thread view controller
            let threadVC = ThreadedMessagesVC()
            threadVC.parentMessage = message
            
            // Navigate to thread screen
            self.navigationController?.pushViewController(threadVC, animated: true)
        })
    }
}

This captures user intent and opens a focused thread screen.

File reference: ThreadedMessagesVC.swift

Step 2: Navigate to the Thread Screen

Show a dedicated UI for thread replies. In ThreadedMessagesVC.swift:

import UIKit
import CometChatUIKitSwift
import CometChatSDK

class ThreadedMessagesVC: UIViewController {
    
    var parentMessage: BaseMessage?
    var user: User?
    var group: Group?
    
    private var parentMessageContainerView: CometChatThreadedMessageHeader!
    private var messageListView: CometChatMessageList!
    private var composerView: CometChatMessageComposer!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupUI()
    }
    
    private func setupUI() {
        // Add UI components to view hierarchy
        view.addSubview(parentMessageView)
        view.addSubview(messageListView)
        view.addSubview(composerView)
    }
}

Header configuration:

// Create the threaded message header
let parentMessageContainerView = CometChatThreadedMessageHeader()

Message list configuration:

// Configure message list with user and parent message
messageListView.set(user: user, parentMessage: parentMessage)

This provides a focused UI for thread interactions.

Step 3: Send a Threaded Message

Ensure new replies are attached to the correct parent message:

// Set the parent message ID for threaded replies
composerView.set(parentMessageId: parentMessage?.id ?? 0)

Set the conversation context:

// Configure composer for user conversation
composerView.set(user: user)

// Or configure for group conversation
composerView.set(group: group)

Step 4: Fetch and Display Thread Replies

Only messages that are part of the thread are displayed. This is handled internally by:

// Configure message list to fetch thread replies
messageListView.set(user: user, parentMessage: parentMessage)

This ensures CometChatMessageList fetches replies using the parentMessageId.

Customization Options

Header Styling

Customize CometChatThreadedMessageHeader appearance:

// Customize fonts, colors, and layout
let headerStyle = ThreadedMessageHeaderStyle()
headerStyle.titleFont = UIFont.systemFont(ofSize: 16, weight: .semibold)
headerStyle.titleColor = .label
parentMessageContainerView.set(style: headerStyle)

Composer

Modify placeholder text, input styles, and icons:

// Customize composer appearance
composerView.set(placeholderText: "Reply in thread...")

Navigation

Add a custom back button for navigation:

// Add custom back button
navigationItem.leftBarButtonItem = UIBarButtonItem(
    image: UIImage(systemName: "chevron.left"),
    style: .plain,
    target: self,
    action: #selector(goBack)
)

Edge Cases

Scenario	Handling
Parent message deleted	Display a fallback UI or disable the composer
No replies	Show an empty state (e.g., “No replies yet”)
Offline mode	Disable the composer and queue thread operations

Error Handling

Error Type	Solution
Fetch failures	Show an error UI or retry mechanism when loading thread messages
Send failures	Handle send errors via delegate callbacks or show an alert with retry
Loading states	Display a UIActivityIndicatorView during fetch/send operations
Blocked users	Remove the composer and display a blocked status label

Feature Matrix

Feature	Implementation
Show thread option	CometChatMessageList.onThreadRepliesClick
Thread view screen	ThreadedMessagesVC.swift
Display threaded messages	CometChatMessageList.set(parentMessage:)
Send threaded message	CometChatMessageComposer.set(parentMessageId:)
Thread header	CometChatThreadedMessageHeader
Handle blocked user	Remove composer and show a blocked user label

Related Components

• Message List - Display messages in conversations
• Message Composer - Compose and send messages
• Threaded Messages Header - Thread header component

Sample App

Explore a complete sample application demonstrating threaded messaging

UIKit Source

Browse the CometChat UIKit for iOS source code

Related Guides

Threaded Messages Header

Customize the thread header component

Message List

Display and customize chat messages

Core Features

Overview of messaging features