How to use timers from classes which are not placed in the level

Development Programming & Scripting C++
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1

Hi,

I am working on UE5.1.

Please look at the following class pseudocode

Class A :  public AActor {
public:
    void CooldownExpirationCallback() { // print something }
    void func_to_use_timers() { 
        GetWorld()->GetTimerManager().SetTimer(CooldownTimerHandle, this, &A ::CooldownExpirationCallback, 5, false, -1);
    }
    FTimerHandle CooldownTimerHandle;
};

If I put this actor on the level in IDE, timers are working without any problem.

But if I create a separate class like below:

Class B :  public AActor {
public:
    void :BeginPlay() { 
        myA= NewObject<A>();
    }
    void useA() { A->func_to_use_timers(); }
    A* myA;
};

And place only B to the level, and call B.useA(), timer won’t work.

I believe I understand the reason: GetWorld() function returns NULL in this case (because B is in the level, not A). Thus, according to UE documentation I have another option, get Timer Manager not through Actor’s GetWorld() method, but through GameInstance().

So, I tried GetGameInstance()->... in order to access TimerManager. But even a pure call to GetGameInstance() (without dereferencing it) crashes the IDE.

So, my question is how to use a timer in such situations (where class owning the method to call GetWorld()->GetTimerManager().SetTimer(…) is not placed on the level).

I would appreciate your help.

2

Maybe what you are looking for is to Extend the original class?

3

Thanks for your reply. Actually I don’t want to extend the original class. Class A is a representation of an ability class. There will be many child classes of this class. On the other hand, Class B represents the playable character class. The reason why Class A is an actor, is because I tried with UObject, and timer’s don’t seem to work there. Since UObject cannot be placed on level, getWorld returns NULL.

I need to understand what should I do so that timers get to work on internal objects that are not on the level.

4

You cannot.
If an object is not in game it has no time or functions for you to call.

5

I get it. Thank you.

The workaround that I did was to pass AAactor pointer into the subobject’s function calling the timer. GetWorld() would be called from the passed pointer.