Mention users

Tag users in chat messages with @ mentions. Type @ followed by at least three letters to see username suggestions.

You can use PubNub's functionality via Blueprints or directly in C++ code.

• In Blueprints, you can access PubNub from any Widget or Actor. Start by initializing chat using InitChat on UPubnubChatSubsystem. Afterwards, you can use the returned UPubnubChat object reference to call all Chat SDK functions.

Blueprint functions

The Blueprints provided in the documentation show how you can structure your application and may contain utility methods and elements like buttons that are not part of the Unreal Chat SDK and are meant to serve as guidance.

• In C++, you can use UPubnubChatSubsystem as any other Game Instance Subsystem.

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  Chat now allows you to call all Chat SDK functions, for example, Chat->GetChannel("my_channel").

Usage in Blueprints and C++

Requires App Context

Enable App Context in the Admin Portal to mention users.

Shared structure

Channel references, user mentions, and links are MessageElement instances with different MentionTarget types.

Configuration options:

• User source: channel members or all app users
• Suggestions: up to 100 usernames (default: 10)
• Username length: up to 200 characters
• Mentions per message: up to 100 (default: 10)

Implementation follows similar patterns to channel referencing and links.

Add user mentions

AddMention() adds user mentions to a draft message. Use CreateUserMentionTarget() to create a mention target linking to a specified User.

Method signature

Add a user mention by calling AddMention() with the MentionTarget of type User.

Refer to the AddMention() method for details.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Create the Hello Alex! I have sent you this link on the #offtopic channel. message where Alex is a user mention.

Actor.h

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Actor.cpp

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Remove user mentions

RemoveMention() removes a user mention from a draft message.

Method signature

Remove a user mention by calling RemoveMention() at the exact offset where the mention starts.

Refer to the RemoveMention() method for details.

Offset value

Provide the exact offset position where the mention starts; otherwise, it won't be removed.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Remove the user mention from the Hello Alex! I have sent you this link on the #offtopic channel. message where Alex is a user mention.

Actor.h

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Actor.cpp

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Get user suggestions

The OnMessageDraftUpdatedWithSuggestions delegate returns users matching a 3-letter string from channel members or global users. Bind this delegate to receive draft changes along with suggestions for user mentions, links, and channel references.

OnMessageDraftUpdatedWithSuggestions delegate:

• Fires when the draft content changes
• Provides the current state of message elements (TArray<FPubnubChatMessageElement>)
• Offers FPubnubChatSuggestedMention items suggesting user mentions, links, or channel references

Unlike OnMessageDraftUpdated, which only delivers content changes, this delegate also includes suggestion data for dynamic draft updates.

Details

Example: typing @Ale returns users starting with Ale like Alex or Alexander. Default: 10 suggestions (max: 100).

Method signature

Refer to the Listen for message draft changes (with suggestions) section for details.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Insert the first mentioned user whenever the draft is updated and users are detected.

Actor.h

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Actor.cpp

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Other examples

Get user suggestions from Chat object

Actor.h

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Actor.cpp

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Get mentioned users

Removed method

MentionedUsers() has been removed from the Message object in the latest version of the Unreal Chat SDK. Mentioned users are now managed through MessageDraft and message elements. To monitor mentions, use the OnMentioned delegate on the User object or StreamMentions().

Collect all user-related mentions

Removed method

GetCurrentUserMentions() has been removed from the Chat object in the latest version of the Unreal Chat SDK. To monitor mentions, use the OnMentioned delegate or StreamMentions(), or GetEventsHistory() to retrieve historical mention events.

Show notifications for mentions

Use the OnMentioned delegate on the User object to receive real-time mention events. Bind the delegate and call StreamMentions() to start receiving mention events targeted to the user. Call StopStreamingMentions() to stop.

Delegate	Type	Payload
OnMentioned	FOnPubnubChatUserMentioned	FPubnubChatUserMention containing mention details (channel ID, message timetoken, etc.).

Sample code

Actor.h

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Actor.cpp

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Emit user mention

Programmatically emit a mention event on a channel with EmitUserMention(). Use this when implementing custom mention logic outside of MessageDraft, for example when processing messages that arrive from external systems.

Method signature

C++ / Input parameters

1Channel->EmitUserMention(
2    const FString UserID,
3    const FString Timetoken,
4    const FString Text
5);

* required

Parameter	Description
UserID * Type: FString Default: n/a	ID of the user being mentioned.
Timetoken * Type: FString Default: n/a	Timetoken of the message that contains the mention.
Text * Type: FString Default: n/a	Content of the message containing the mention.

Blueprint

Output

Type	Description
FPubnubChatOperationResult	Contains Error and ErrorMessage. Check Error to determine if the event was emitted successfully.

Sample code

Reference code

This example is a self-contained code snippet ready to be run. Set up your Unreal project and follow the instructions in the lines marked with ACTION REQUIRED before running the code. Use it as a reference when working with other examples in this document.

Emit a mention event for a user on a channel.

Actor.h

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Actor.cpp

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