GetWorld() returns null within a UWorldSubsystem

Development Programming & Scripting
, ,
2

When are you calling your function? It needs to be around begin play for the world to exist.

.h

#pragma once

#include "CoreMinimal.h"
#include "Subsystems/WorldSubsystem.h"
#include "MyWorldSubsystem.generated.h"

UCLASS()
class YOUR_API UMyWorldSubsystem : public UWorldSubsystem
{
	GENERATED_BODY()
public:
	UFUNCTION(BlueprintCallable)
	void CallFunc();
	
};

.cpp

#include "MyWorldSubsystem.h"

void UMyWorldSubsystem::CallFunc()
{
	// GetWorld() returns null here?!
	if(!GetWorld())
	{
		GEngine->AddOnScreenDebugMessage(1, 4, FColor::Red, "World is null");
	} else
	{
		GEngine->AddOnScreenDebugMessage(1, 4, FColor::Green, "World is ok");
	}
}

Tester class

.h

just basic actor header

.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "WorldTester.h"
#include "MyWorldSubsystem.h"

// important 

void AWorldTester::BeginPlay()
{
	Super::BeginPlay();

	UMyWorldSubsystem * ws = GetWorld()->GetSubsystem<UMyWorldSubsystem>();
	ws->CallFunc();
}

Gives info

image