FPendingLatentAction is nullptr in handler

Development Programming & Scripting
1

Pending action class

class myPendingLatentAction: public FPendingLatentAction {
public:
	TSharedPtr<IHttpRequest> Request;
	FLatentActionInfo info;
	TSharedPtr<FString> result = MakeShareable<FString>(new FString(TEXT("")));
	bool complete = false;
	bool success = false;
	myPendingLatentAction(TSharedPtr<IHttpRequest> Request, FLatentActionInfo info) : Request(Request), info(info)
	{}
	virtual void UpdateOperation(FLatentResponse& Update) override
	{
		GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("Complete ---------"));
		Update.FinishAndTriggerIf(complete, info.ExecutionFunction, info.Linkage, info.CallbackTarget);
	}
};

Latent function

bool Ujson2structBPLibrary::TestUrlLatent(FString URL, FString JSON, FString& result, FLatentActionInfo info, UObject* WC)
{
	UWorld * World = GEngine->GetWorldFromContextObject(WC); //TODO deprecated lookup replacement
	if (!World) { return false; }
	FLatentActionManager& LatentManager = World->GetLatentActionManager();
	FHttpModule* Http = &FHttpModule::Get();
	TSharedPtr<IHttpRequest> Request = Http->CreateRequest();
	myPendingLatentAction* RequestAction = new myPendingLatentAction(Request, info);
	if (LatentManager.FindExistingAction<myPendingLatentAction>(info.CallbackTarget, info.UUID) != NULL) { return false; }
	LatentManager.AddNewAction(info.CallbackTarget, info.UUID, RequestAction);
	Request->SetURL(URL);
	Request->SetVerb("GET");
	Request->SetContentAsString(JSON);
	Request->SetHeader("User-Agent", "X-UrealEngine-Agent");
	Request->SetHeader("Content-Type", "application/json");
	Request->SetHeader("Accept", "application/json");
	Request->OnProcessRequestComplete().BindLambda(
		[&RequestAction,&result](FHttpRequestPtr request, FHttpResponsePtr response, bool success)
		{
			if (success) 
			{
				auto temp = response->GetContentAsString();
//This part displays the http response if the next bit is commented 
				GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, temp);
// this compiles but throws an exception
				RequestAction->result->Append(temp);				
			}
			RequestAction->success = success;
			RequestAction->complete = true;			
		}
	);
	Request->ProcessRequest();	
	return true;
}
2

Looks like myPendingLatentAction gets destroyed before the handler is called. Which is odd because myPendingLatentAction is dynamically allocated with new so it should be on the heap requiring an explicit deallocation. Every NEW requires delete I’ve tried making it a shared pointer and so forth.

3

This version of myPendingLatentAction displays “me is null”

class myPendingLatentAction: public FPendingLatentAction {
public:
	TSharedPtr<IHttpRequest> Request;
	FLatentActionInfo info;
	FString& result;
	bool complete = false;
	bool success = false;
	myPendingLatentAction(TSharedPtr<IHttpRequest> Request, FLatentActionInfo info, FString& result) : Request(Request), info(info), result(result)
	{}

	virtual void UpdateOperation(FLatentResponse& Update) override
	{
		if (complete) {
			GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("Complete ---------"));
			Update.FinishAndTriggerIf(complete, info.ExecutionFunction, info.Linkage, info.CallbackTarget);
			Update.DoneIf(complete);
		}
	}

	static void responseHandler(myPendingLatentAction* me, FHttpRequestPtr request, FHttpResponsePtr response, bool success)
	{
		if (me == nullptr)
		{
			GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("me is null"));
		}
	}
};
4

Displays “this is null”

class myPendingLatentAction: public FPendingLatentAction {
...
	void responseHandler(FHttpRequestPtr request, FHttpResponsePtr response, bool success)
	{
		if (this == nullptr)
		{
			GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("this is null"));
		}
	}
};
5

Changed my Lambda set up to grab the object as pointer rather a reference

bool Ujson2structBPLibrary::TestUrlLatent(FString URL, FString JSON, FString& result, FLatentActionInfo info, UObject* WC)
{
	result = *(new FString(L"WHY"));
	UWorld * World = GEngine->GetWorldFromContextObject(WC, EGetWorldErrorMode::ReturnNull);
	if (!World) { return false; }
	FLatentActionManager& LatentManager = World->GetLatentActionManager();
	FHttpModule* Http = &FHttpModule::Get();
	TSharedPtr<IHttpRequest> Request = Http->CreateRequest();
	if (LatentManager.FindExistingAction<myPendingLatentAction>(info.CallbackTarget, info.UUID) != NULL) { return false; }
	myPendingLatentAction* RequestAction = new myPendingLatentAction(Request,info,result);
	LatentManager.AddNewAction(info.CallbackTarget, info.UUID, RequestAction);
	Request->SetURL(URL);
	Request->SetVerb("GET");
	Request->SetContentAsString(JSON);
	Request->SetHeader("User-Agent", "X-UrealEngine-Agent");
	Request->SetHeader("Content-Type", "application/json");
	Request->SetHeader("Accept", "application/json");
	Request->OnProcessRequestComplete().BindLambda(
		[RequestAction](FHttpRequestPtr request, FHttpResponsePtr response, bool success)
		{
			myPendingLatentAction::responseHandler(RequestAction,request, response, success);
		}
	);
	Request->ProcessRequest();	
	return true;
}