Add Limit and Offset inputs to ListUsersFromChannel function. (#55)

feat(hereNow): Add Limit and Offset inputs to ListUsersFromChannel function.

The ListUsersFromChannel method now returns a maximum of 1,000 occupants per channel. Previously, it would return all occupants regardless of count. If you have channels with more than 1,000 occupants, you must use pagination (new Limit and Offset parameters) to retrieve the complete list. BREAKING CHANGE

Author: KGronek-Pubnub

.pubnub.yml

@@ -1,8 +1,13 @@
 name: unreal-engine
 schema: 1
-version: v1.0.0
+version: 1.2.0
 scm: github.com/pubnub/unreal-engine
 changelog:
+  - date: 2025-11-12
+    version: 1.2.0
+    changes:
+      - type: feature
+        text: "The `ListUsersFromChannel` method now returns a maximum of 1,000 occupants per channel. Previously, it would return all occupants regardless of count. If you have channels with more than 1,000 occupants, you must use pagination (new `Limit` and `Offset` parameters) to retrieve the complete list. **BREAKING CHANGE**."
   - date: 2025-09-11
     version: 1.1.0
     changes:

PubnubLibrary.uplugin

@@ -1,7 +1,7 @@
 {
 	"FileVersion": 3,
-	"Version": 12,
-	"VersionName": "1.1.0",
+	"Version": 13,
+	"VersionName": "1.2.0",
 	"FriendlyName": "Pubnub Unreal SDK",
 	"Description": "Quickly add interactive features to your game that scale without building your backend infrastructure.",
 	"Category": "Code",

Source/PubnubLibrary/Private/FunctionLibraries/PubnubJsonUtilities.cpp

@@ -250,8 +250,10 @@ void UPubnubJsonUtilities::ListUsersFromChannelJsonToData(FString ResponseJson,
 		Result.ErrorMessage = "Failed to parse Response";
 		return;
 	}
-
-	Result = GetOperationResultFromJson(JsonObject);
+	FPubnubOperationResult ResultFromJson = GetOperationResultFromJson(JsonObject);
+	Result.ErrorMessage = ResultFromJson.ErrorMessage;
+	//Override status only if it was 0. Status could be set before in case of server error.
+	Result.Status = Result.Status == 0 ? ResultFromJson.Status : Result.Status;
 	Result.Error = Result.Status != 200;
 
 	JsonObject->TryGetNumberField(ANSI_TO_TCHAR("occupancy"), Data.Occupancy);

Source/PubnubLibrary/Private/PubnubInternalMacros.h

@@ -63,7 +63,6 @@
  *   - Log an error message to the output log
  *   - Invoke the provided delegate with a failure result and optional additional arguments
  *   - Immediately return from the calling function
- *
  */
 #define PUBNUB_ENSURE_USER_ID_IS_SET(Delegate, ...) \
 	do { \
@@ -75,13 +74,30 @@
 		} \
 	} while (false)
 
+/**
+ * Verifies that provided condition is met.
+ *
+ * If the condition is not met, this macro will:
+ *   - Log an error message to the output log
+ *   - Invoke the provided delegate with a failure result and optional additional arguments
+ *   - Immediately return from the calling function
+ */
+#define PUBNUB_ENSURE_CONDITION(Condition, ErrorMessage, Delegate, ...) \
+	do { \
+		if (!(Condition)) \
+		{ \
+			PubnubError(FString::Printf(TEXT("[%s]: %s Aborting operation."), *UPubnubUtilities::GetNameFromFunctionMacro(ANSI_TO_TCHAR(__FUNCTION__)), ErrorMessage)); \
+			UPubnubUtilities::CallPubnubDelegateWithInvalidArgumentResult(Delegate, ErrorMessage, ##__VA_ARGS__); \
+			return; \
+		} \
+	} while (false)
+
 /**
  * Verifies that a valid Pubnub user ID has been set before continuing.
  *
  * If the user ID is not set, this macro will:
  *   - Log an error message to the output log
  *   - Immediately return from the calling function
- *
  */
 #define PUBNUB_RETURN_IF_USER_ID_NOT_SET(...) \
 	do { \
@@ -135,4 +151,4 @@
 			PubnubError(FString::Printf(TEXT("[%s]: %s field can't be empty. Aborting operation."), *UPubnubUtilities::GetNameFromFunctionMacro(ANSI_TO_TCHAR(__FUNCTION__)), TEXT(#Field)), EPubnubErrorType::PET_Warning); \
 			return __VA_ARGS__; \
 		} \
-	} while (false)
+	} while (false)

Source/PubnubLibrary/Private/PubnubSubsystem.cpp

@@ -1880,6 +1880,8 @@ void UPubnubSubsystem::ListUsersFromChannel_priv(FString Channel, FOnListUsersFr
 {
 	PUBNUB_ENSURE_USER_ID_IS_SET(ListUsersFromChannelResponse, FPubnubListUsersFromChannelWrapper());
 	PUBNUB_ENSURE_FIELD_NOT_EMPTY(Channel, ListUsersFromChannelResponse, FPubnubListUsersFromChannelWrapper());
+	PUBNUB_ENSURE_CONDITION(ListUsersFromChannelSettings.Limit >= 0, TEXT("Limit can't be below 0."), ListUsersFromChannelResponse, FPubnubListUsersFromChannelWrapper());
+	PUBNUB_ENSURE_CONDITION(ListUsersFromChannelSettings.Offset >= 0, TEXT("Offset can't be below 0."), ListUsersFromChannelResponse, FPubnubListUsersFromChannelWrapper());
 
 	//Set all options from ListUsersFromChannelSettings
 	FUTF8StringHolder ChannelHolder(Channel);
@@ -1895,8 +1897,17 @@ void UPubnubSubsystem::ListUsersFromChannel_priv(FString Channel, FOnListUsersFr
 
 	FString JsonResponse = GetLastResponse(ctx_pub);
 
-	//Execute provided delegate with results
 	FPubnubOperationResult Result;
+	
+	//If response is empty, there was server error. 
+	if(JsonResponse.IsEmpty())
+	{
+		JsonResponse = UPubnubUtilities::PubnubGetLastServerHttpResponse(ctx_pub);
+		//Presence api doesn't provide status code in the response, so we need to get it manually
+		Result.Status = pubnub_last_http_code(ctx_pub);
+	}
+	
+	//Execute provided delegate with results
 	FPubnubListUsersFromChannelWrapper Data;
 	UPubnubJsonUtilities::ListUsersFromChannelJsonToData(JsonResponse, Result, Data);
 	UPubnubUtilities::CallPubnubDelegate(ListUsersFromChannelResponse, Result, Data);
@@ -2867,6 +2878,8 @@ void UPubnubSubsystem::HereNowUESettingsToPubnubHereNowOptions(FPubnubListUsersF
 	PubnubHereNowOptions.disable_uuids = HereNowSettings.DisableUserID;
 	PubnubHereNowOptions.state = HereNowSettings.State;
 	HereNowSettings.ChannelGroup.IsEmpty() ? PubnubHereNowOptions.channel_group = NULL : nullptr;
+	PubnubHereNowOptions.limit = HereNowSettings.Limit;
+	PubnubHereNowOptions.offset = HereNowSettings.Offset;
 }
 
 void UPubnubSubsystem::SetStateUESettingsToPubnubSetStateOptions(FPubnubSetStateSettings& SetStateSettings, pubnub_set_state_options& PubnubSetStateOptions)

Source/PubnubLibrary/Public/PubnubStructLibrary.h

@@ -83,6 +83,8 @@ struct FPubnubListUsersFromChannelSettings
 	UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Pubnub") bool DisableUserID = true;
 	//If true (and if DisableUserID is false), will give associated state alongside user info.
 	UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Pubnub") bool State = false;
+	UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Pubnub") int Limit = 1000;
+	UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Pubnub") int Offset = 0;
 };
 
 USTRUCT(BlueprintType)