Watch channels

Use Connect() to receive messages on a channel without joining as a member. Connect() subscribes to the channel. Bind the OnMessageReceived delegate before calling Connect(). Messages are received via this delegate. Use Disconnect() to stop receiving messages.

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++

Asynchronous and synchronous method execution

Most PubNub Unreal SDK methods are available in both asynchronous and synchronous variants.

• Asynchronous methods (Async suffix) return void and take an optional delegate parameter that fires when the operation completes.

  1Channel->ConnectAsync(OnConnectResponseDelegate);

  You can also use native callbacks that accept lambdas instead of dynamic delegates. Native callback types have the Native suffix (for example, FOnPubnubChatOperationResponseNative).

• Synchronous methods (no suffix) block the main game thread until the operation completes and return a result struct directly.

  1FPubnubChatOperationResult Result = Channel->Connect();

Method signature

C++ / Input parameters

1Channel->Connect();

Blueprint

Channel->Connect() takes no parameters and returns FPubnubChatOperationResult.

Output

Type	Description
FPubnubChatOperationResult	Contains Error (bool) and ErrorMessage (FString). Check Error to determine if the operation succeeded.

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.

Connect to a channel and start listening for messages.

C++

Actor.h

1

Actor.cpp

1

Blueprint

Other examples

Stop receiving messages on the support channel.

C++

1

Blueprint