Join channels

Join() connects a user to a given channel and sets membership - this way, the chat user can both watch the channel's content and be its full-fledged member.

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

• In Blueprints, the whole SDK is managed by a subsystem, so start by initalizing the PubnubChatSubsystem node. Afterwards, you can use the Pubnub Chat object reference.

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 the PubNub SDK as any other Game Instance Subsystem.

  #include "Kismet/GameplayStatics.h"
  #include "PubnubChatSubsystem.h"
  
  
  UGameInstance* GameInstance = UGameplayStatics::GetGameInstance(this);
  UPubnubChatSubsystem* PubnubChatSubsystem = GameInstance->GetSubsystem<UPubnubChatSubsystem>();
  
  
  UPubnubChat* Chat = PubnubChatSubsystem ->InitChat("demo", "demo", "my_user") // config optional

  Chat now allows you to call all Chat SDK functions, for example:

  Chat->DeleteUser("SomeUserID");

Usage in Blueprints and C++

Requires App Context

To set up and manage channel membership, you must enable App Context for your app's keyset in the Admin Portal.

Method signature

Join() accepts a callback function and a set of parameters as arguments. The Unreal Chat SDK invokes this callback whenever the current user receives a new message on a channel they have just joined. It subscribes the user to a channel and adds a message event listener underneath. The method also sets user and channel membership by creating a new Membership object that holds the user-channel relation.

Blueprint

C++ / Input parameters

1Channel->Join(
2    FOnPubnubChannelMessageReceived MessageCallback, 
3    FPubnubChatMembershipData MembershipData = FPubnubChatMembershipData()
4);

* required

Parameter	Description
MessageCallback * Type: FOnPubnubChannelMessageReceived Default: n/a	Callback function passed as a parameter. It defines the custom behavior to be executed when detecting a new Message object on the joined channel.
FPubnubChatMembershipData Type: FPubnubChatMembershipData Default: n/a	The object containing all membership data. For more information, refer to FPubnubChatMembershipData.

Output

This method doesn't return any value.

Sample code

Join the support channel and mark this membership as premium to add information about your support plan.

1#include "Kismet/GameplayStatics.h"
2#include "PubnubChatSubsystem.h"
3

4UGameInstance* GameInstance = UGameplayStatics::GetGameInstance(this);
5UPubnubChatSubsystem* PubnubChatSubsystem = GameInstance->GetSubsystem<UPubnubChatSubsystem>();
6

7UPubnubChat* Chat = PubnubChatSubsystem ->InitChat("demo", "demo", "my_user");
8

9UPubnubChannel* Channel = Chat->GetChannel("support");
10

11// Create a pubnub response delegate
12// you MUST implement your own callback function to handle the response
13FOnPubnubChannelMessageReceived MessageCallback;
14MessageCallback.BindDynamic(this, &AMyActor::OnMessageReceived);
15

16FPubnubChatMembershipData MembershipData;
17MembershipData.CustomDataJson = "{\"role\": \"premium-support\"}";
18MembershipData.Status = "active";
19MembershipData.Type = "player";
20

21Channel->Join(MessageCallback, MembershipData);

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