Manage message updates

Requires Message Persistence

Enable Message Persistence in the Admin Portal.

Edit messages and receive real-time update events.

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++

Edit messages

EditText() replaces an existing message's content.

Method signature

Blueprint

C++ / Input parameters

1Message->EditText(FString NewText);

* required

Parameter	Description
newText * Type: string Default: n/a	New/updated text that you want to add in place of the existing message.

Output

This method doesn't return anything.

Sample code

Correct the number of the support ticket you sent to 78398.

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

11FString Timetoken = "16200000000000001";
12

13// Fetch the message
14UPubnubMessage* Message = Channel->GetMessage(Timetoken);
15

16Message->EditText("Your ticket number is 78398.")

show all 16 lines

Get message updates

Receive real-time updates when messages or reactions change:

• StreamUpdates() - updates for a single Message object
• StreamUpdatesOn() - updates for multiple Message objects

Both return a stop object to unsubscribe.

Stream update behavior

• StreamUpdates() returns the entire updated Message on each change
• StreamUpdatesOn() returns the complete list of monitored messages on each change

Method signature

Blueprint

C++ / Input parameters

• StreamUpdates()

  1Message->StreamUpdates(FOnPubnubMessageStreamUpdateReceived MessageUpdateCallback);

• StreamUpdatesOn()

  1Message->StreamUpdatesOn(
  2    TArray<UPubnubMessage*> Messages, 
  3    FOnPubnubMessageStreamUpdateReceived MessageUpdateCallback
  4);

Parameter	Required in StreamUpdates()	Required in StreamUpdatesOn()	Description
Messages Type: TArray<UPubnubMessage*> Default: n/a	No	Yes	Array of Message objects for which you want to get updates.
MessageUpdateCallback Type: FOnPubnubMessageStreamUpdateReceived Default: n/a	Yes	Yes	Callback function passed as a parameter to both methods. It defines the custom behavior to be executed when detecting channel metadata changes.

Each function in the Unreal Chat SDK that takes a callback as a parameter requires you to handle the response type accordingly.

For example, you can bind a callback function for the Channel->StreamPresence method to its handler in the following way:

1// Create a pubnub response delegate
2// you MUST implement your own callback function to handle the response
3FOnPubnubChannelStreamPresenceReceived PresenceResponse;
4PresenceResponse.BindDynamic(this, &AMyActor::OnPresenceResponseReceived);
5

6Channel->StreamPresence(PresenceResponse);

You can implement the callback function to handle the response as follows:

AMyActor.h

1UFUNCTION()
2void OnPresenceResponseReceived(const TArray<FString> &PresentUsersIDs);

AMyActor.cpp

1void AMyActor::OnPresenceResponseReceived(const TArray<FString> &PresentUsersIDs)
2{
3	for(auto PresentUser : PresentUsersIDs)
4	{
5		UE_LOG(LogTemp, Log, TEXT("Present User ID: "), *PresentUser);
6	}
7}

Handle the response

Output

Type	Description
UPubnubCallbackStop*	Object on which you can call Stop() to stop receiving updates.

Sample code

• StreamUpdates()

  Get message and message reaction-related updates for the message with the timetoken 16200000000000000 published on the support channel.

  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
  
  11FString Timetoken = "16200000000000000";
  12
  
  13// Fetch the message
  14UPubnubMessage* Message = Channel->GetMessage(Timetoken);
  15
  
  16// Create a pubnub response delegate
  17// you MUST implement your own callback function to handle the response
  18FOnPubnubMessageStreamUpdateReceived StreamUpdatesResponse;
  19StreamUpdatesResponse.BindDynamic(this, &AMyActor::OnStreamUpdatesMessageResponseReceived);
  20
  
  21Message->StreamUpdates(StreamUpdatesResponse);

  show all 21 lines

• StreamUpdatesOn()

  Get message and message reaction-related updates for several messages published on the support channel.

  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 // Get the channels and save the reference
  11UPubnubMessage* Message1 = Channel->GetMessage("16200000000000000");
  12UPubnubMessage* Message2 = Channel->GetMessage("16200000000000001");
  13
  
  14TArray<UPubnubMessage*> Messages;
  15Messages.Add(Message1);
  16Messages.Add(Message2);
  17
  
  18// Create a pubnub response delegate
  19// you MUST implement your own callback function to handle the response
  20FOnPubnubMessageStreamUpdateReceived StreamUpdatesResponse;
  21StreamUpdatesResponse.BindDynamic(this, &AMyActor::OnStreamUpdatesOnMessageResponseReceived);
  22
  
  23Message->StreamUpdatesOn(Messages, MessagesStreamUpdatesResponse);

  show all 23 lines

Other examples

• StreamUpdates()

  Stop listening to updates for the message with the timetoken 16200000000000000 published on the support channel.

  1auto StopUpdates = Message->StreamUpdates(StreamUpdatesResponse);
  2
  
  3StopUpdates->Stop();

• StreamUpdatesOn()

  Stop listening to updates for the last ten messages published on the support channel.

  1auto StopUpdates = Message->StreamUpdatesOn(Messages, MessagesStreamUpdatesResponse);
  2
  
  3StopUpdates->Stop();