Mentions Formatter

Add @mentions with user suggestions and styled tokens in CometChat Flutter UI Kit.

AI Agent Component Spec

Field	Value
Package	cometchat_chat_uikit
Key class	CometChatMentionsFormatter (extends CometChatTextFormatter)
Init	CometChatUIKit.init(uiKitSettings) then CometChatUIKit.login(uid)
Purpose	Add @mentions with user suggestions, styled tokens, and click handling
Sample app	GitHub
Related	Custom Text Formatter · Custom Mentions Formatter · All Guides

Overview

The CometChatMentionsFormatter class is a part of the CometChat UI Kit, a ready-to-use chat UI widget library for integrating CometChat into your Android applications. This class provides functionality to format mentions within text messages displayed in the chat interface. Mentions allow users to reference other users within a conversation, providing a convenient way to direct messages or involve specific participants.

Android

iOS

Features

• Mention Formatting: Automatically formats mentions within text messages based on provided styles and settings.
• Customizable Styles: Allows customization of text styles for mentions, including colors, fonts, and background colors.
• User and Group Member Mentions: Supports mentions for both individual users and group members, providing flexibility in communication scenarios.
• Mention List Generation: Generates a list of suggested mentions based on user input, facilitating easy selection of recipients during message composition.
• Mention Click Handling: Provides a listener interface for handling click events on mentions, enabling custom actions to be performed when a mention is tapped by the user.

Usage

To integrate the CometChatMentionsFormatter class into your application:

1. Initialization: Create an instance of the CometChatMentionsFormatter class and configure it with desired settings, such as mention text styles and limit settings.

2. Set Mention Listeners: Set listeners for handling mention click events (setOnMentionClick).

3. Format Messages: Use the prepareLeftMessageBubbleSpan, prepareRightMessageBubbleSpan, prepareComposerSpan, and prepareConversationSpan methods to format text messages with mentions appropriately for display in the chat interface.

4. Customization: Customize the appearance and behavior of mentions by adjusting the text styles, colors, and other formatting properties as needed.

Below is an example demonstrating how to use the CometChatMentionsFormatter class in widgets such as CometChatConversations, CometChatMessageList, CometChatMessageComposer.

Dart

textFormatters: [
    CometChatMentionsFormatter(
      messageBubbleTextStyle: (theme, alignment,{forConversation = false}) => 
        TextStyle(
            color: alignment==BubbleAlignment.left? Colors.orange : Colors.pink,
            fontSize: 14,
            fontWeight: FontWeight.bold
        ),
    )
]

---

Actions

Actions dictate how a widget functions. They are divided into two types: Predefined and User-defined. You can override either type, allowing you to tailor the behavior of the widget to fit your specific needs.

onMentionTap

Setting a listener for mention-click events in Message Bubbles enhances interactivity within the chat. This listener is activated when a mention is clicked, returning the corresponding user object. This feature transforms mentions into interactive links, enabling more in-depth and contextual engagement with the user associated with the clicked mention.

Dart

CometChatMessages(
  user: user,
  messageListConfiguration: MessageListConfiguration(
      textFormatters: [
        CometChatMentionsFormatter(
          onMentionTap: (mention, mentionedUser, {message}) {
            final snackBar = SnackBar(
              content: const Text('Tap on Mentioned User', style: TextStyle(color: Colors.lightBlueAccent)),
              action: SnackBarAction(
                label: 'Undo',
                onPressed: () {
                  // TODO("Not yet implemented")
                },
              ),
            );
            ScaffoldMessenger.of(context).showSnackBar(snackBar);
          },
          messageBubbleTextStyle: (theme, alignment,{forConversation = false}) => TextStyle(
              color: alignment==BubbleAlignment.left? Colors.orange : Colors.greenAccent,
              fontSize: 14,
              fontWeight: FontWeight.bold
          ),
        )
      ]
  ),
)

Android

iOS

---

Customization

Property	Description	Code
trackingCharacter	The character that triggers the mention search.	String? trackingCharacter
pattern	The regex pattern to identify mentions.	RegExp? pattern
showLoadingIndicator	Whether to show a loading indicator during mention search.	bool? showLoadingIndicator
onSearch	Callback function to perform search when mention is triggered.	void Function(String)? onSearch
onError	Callback function to handle errors during mention search.	void Function(String)? onError
message	The message in which mentions are to be formatted.	String? message
messageBubbleTextStyle	The text style for the message bubble.	TextStyle? messageBubbleTextStyle
messageInputTextStyle	The text style for the message input.	TextStyle? messageInputTextStyle
composerId	The unique identifier for the composer.	String? composerId
suggestionListEventSink	The event sink for the suggestion list.	EventSink<List<User>>? suggestionListEventSink
previousTextEventSink	The event sink for the previous text before mention.	EventSink<String>? previousTextEventSink
user	The user to be mentioned.	User? user
group	The group in which mentions are to be formatted.	Group? group
groupMembersRequestBuilder	The request builder for fetching group members to mention.	GroupMembersRequestBuilder? groupMembersRequestBuilder
usersRequestBuilder	The request builder for fetching users to mention.	UsersRequestBuilder? usersRequestBuilder
mentionsType	The type of mentions (e.g., user, group).	MentionsType? mentionsType
onMentionTap	Callback function to handle mention tap actions.	void Function(User)? onMentionTap
visibleIn	Defines where the mentions are visible.	Set<ComposerMentionVisibility>? visibleIn
style	Style configuration for customizing mention appearance.	CometChatMentionsStyle? style
disableMentions	Disables mentions in the composer (default: false).	bool disableMentions
disableMentionAll	Controls whether @all mention is enabled (default: false).	bool disableMentionAll
mentionAllLabel	Custom label to display for @all mention.	String? mentionAllLabel
mentionAllLabelId	Custom ID for @all mention (default: “all”).	String? mentionAllLabelId

---

Advance

For advanced-level customization, you can set the style of the Mentions formatters. This lets you tailor each aspect of the widget to fit your exact needs and application aesthetics. You can create and define your formatters style.

Custom Mentions Formatter

For deeper customization — such as filtering who appears in the suggestion list, transforming suggestions before they reach the UI, or handling mention taps with custom logic — you can extend CometChatMentionsFormatter and override its behavior. See the Custom Mentions Formatter guide for a full walkthrough.

@all Mention Feature

The CometChatMentionsFormatter supports mentioning all members in a group using the @all feature. When enabled, users can type @ followed by “all” (or a custom label) to notify everyone in the group.

Dart

CometChatMessages(
  group: group,
  messageComposerConfiguration: MessageComposerConfiguration(
    textFormatters: [
      CometChatMentionsFormatter(
        disableMentionAll: false, // Enable @all mention (default)
        mentionAllLabel: "everyone", // Custom label (optional)
        mentionAllLabelId: "all", // Custom ID (optional)
      )
    ]
  ),
)

To disable the @all mention feature:

Dart

CometChatMentionsFormatter(
  disableMentionAll: true, // Disable @all mention
)

---

Composer Mention Text Style

Assigns the list of text formatters. If the provided list is not null, it sets the list. Otherwise, it assigns the default text formatters retrieved from the data source. To configure the existing Mentions look and feel for CometChatMessageComposer refer to the below code snippet

Dart

CometChatMessages(
    user: user,
    messageComposerConfiguration: MessageComposerConfiguration(
        textFormatters: [
            CometChatMentionsFormatter(
                messageInputTextStyle: (theme) {
                    return const TextStyle(
                    color: Colors.lightBlueAccent,
                    fontSize: 14,
                    fontWeight: FontWeight.bold
                );
            },
        )
        ]
    )
)

Android

iOS

---

Message Bubble Mention Text Style

Assigns the list of text formatters. If the provided list is not null, it sets the list. Otherwise, it assigns the default text formatters retrieved from the data source. To configure the existing Mentions look and feel for CometChatMessageList

Dart

CometChatMessages(
  user: user,
  messageListConfiguration: MessageListConfiguration(
      textFormatters: [
        CometChatMentionsFormatter(
          messageBubbleTextStyle: (theme, alignment,{forConversation = false}) => TextStyle(
              color: alignment==BubbleAlignment.left? Colors.orange : Colors.greenAccent,
              fontSize: 14,
              fontWeight: FontWeight.bold
          ),
        )
      ]
  ),
)

Android

iOS

---

Conversations Mention Text Style

Assigns the list of text formatters. If the provided list is not null, it sets the list. Otherwise, it assigns the default text formatters retrieved from the data source. To configure the existing Mentions look and feel for CometChatConversations

Dart

CometChatConversations(
  textFormatters: [
    CometChatMentionsFormatter(
      messageBubbleTextStyle: (theme, alignment,{forConversation = false}) =>
          const TextStyle(
              color: Colors.lightBlueAccent,
              fontSize: 14,
              fontWeight: FontWeight.bold
          ),
    )
  ],
)

Android

iOS

---

Next Steps

Custom Mentions Formatter

Build a custom mentions formatter with filtered suggestions.

Custom Text Formatter

Build custom inline text patterns with regex.

Message Composer

Customize the standard message input component.

All Guides

Browse all feature and formatter guides.