Message history

PubNub APIs let you effectively fetch historical messages from direct, group, or public conversations.

While App Context API lets you manage metadata and relationships between users and channels, enabling efficient tracking of which channels are associated with a given user, Message Persistence API lets you retrieve messages from those channels. Together, these APIs enable you to gather all conversations involving a user and easily fetch specific message histories for any interactions between users.

Use GetHistory() to fetch past messages from a channel.

API limitation

Results cannot be filtered by message type. All messages within the specified timeframe are returned.

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++

Method signature

Blueprint

C++ / Input parameters

1Channel->GetHistory(
2    int Limit, 
3    FString Start, 
4    FString End
5);

* required

Parameter	Description
Start Type: FString Default: n/a	Timetoken delimiting the start of a time slice (exclusive) to pull messages from. For details, refer to the Fetch History section.
End Type: FString Default: n/a	Timetoken delimiting the end of a time slice (inclusive) to pull messages from. For details, refer to the Fetch History section.
Limit Type: int Default: 25	Number of historical messages to return for the channel in a single call. Since each call returns all attached message reactions by default, the maximum number of returned messages is 25.

Output

Parameter	Description
TArray<UPubnubMessage*>	Array listing the requested number of historical Message objects.

By default, each call returns all message reactions and metadata attached to the retrieved messages.

Sample code

From the support channel, fetch 10 historical messages older than the timetoken 15343325214676133.

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// Define parameters for the GetHistory method
12int Limit = 10;
13FString StartTimetoken = "15343325214676133";
14FString EndTimetoken; // Empty FString means no end timetoken will be used
15

16// Fetch historical messages
17TArray<UPubnubMessage*> Messages = Channel->GetHistory(Limit, StartTimetoken, EndTimetoken);

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