How to Call timer X number of time inside static function?

Development Programming & Scripting
1

I actually solved this problem, but posting question as per my PR on github, to find out possibly better solution.

The problem is I have static function, in which I create timer. I want this timer to run X number of times every Y seconds.

There is currently no way, to setup timer to run limited number of times. Once you you fire it loop, it will loop indefinitely, which is not what I want.

So I created second function, which is called by second timer, to work around static “limitation” i pass to it handle number:

void UAREffectStatics::SpawnProjectileInAreaInterval(TSubclassOf<class AARProjectile> Projectile, AActor* Causer, APawn* Instigator, const FHitResult& HitResult, const FARProjectileInfo& ProjectileInfo, int32 Amount, float MinTime, float MaxTime)
{
	if (HitResult.bBlockingHit)
	{
		FTimerManager& TimerManager = Causer->GetWorld()->GetTimerManager();
		FTimerManager& DurationTimer = Causer->GetWorld()->GetTimerManager();
		FTimerHandle IntervalHandle;
		FTimerHandle DurationHandle;
		FTimerDelegate del = FTimerDelegate::CreateStatic(&UAREffectStatics::SpawnProjectile, Projectile, Causer, HitResult, ProjectileInfo);
		TimerManager.SetTimer(IntervalHandle, del, MinTime, true, 0);
		float duration = Amount * MaxTime + KINDA_SMALL_NUMBER;
		FTimerDelegate durDel = FTimerDelegate::CreateStatic(&UAREffectStatics::StopTimer, Causer, IntervalHandle.GetHandle());
		DurationTimer.SetTimer(DurationHandle, durDel, duration, false);
		float CurrentTime = 0;
		int32 counter = 0;
	}
}

void UAREffectStatics::StopTimer(AActor* Causer, int32 HandleIn)
{
	FTimerHandle Handle = FTimerHandle(HandleIn);
	FTimerManager& Timer = Causer->GetWorld()->GetTimerManager();
	Timer.ClearTimer(Handle);
	//Timer.ClearTimer(TimerHandle);
}
2

In your pull request you mentioned that you’d tried passing a reference to the FTimerHandle. Looking at the code as written this won’t work because you only have a temporary copy of the FTimerHandle so the reference would be invalid when StopTimer is called. Is there a reason you didn’t just pass a copy of the FTimerHandle?

3

When you included the timer manager in your header file did it give you the same error or something different?

4

Is this code in a module? You may need to update the module’s dependencies. The module dependencies are in the .build.cs file for the module. Make sure “Engine” is listed in the PublicDependencyModuleNames list.

5

AREffectStatics.h(91): error : In AREffectStatics: Unrecognized type ‘FTimerHandle’

So I thought, missing header included and added:

#include "TimerManager.h"

But that didn’t helped.

Maybe the fact that I’m using it inside static function have something to do with it ?

6

It was the same error.

7

Try making the following changes inside TimerManager.h and see if it fixes things for you. Add USTRUCT() directly above the line that says struct FTimerHandle and add GENERATED_USTRUCT_BODY() inside the FTimerHandle on a line before the default constructor.

8

After adding USTRUCT() and USTRUCT_GENERATED_BODY():

Engine.generated.4.cpp(20164): error C3861: 'Z_Construct_UClass_UTimerManager': identifier not found

Microsoft.MakeFile.Targets(38,5): error MSB3073: The command "Build.bat ActionRPGGameEditor Win64 DebugGame "\ActionRPGGame.uproject"" exited with code -1.
Engine.generated.4.cpp(20164): error C3861: 'Z_Construct_UClass_UTimerManager': identifier not found

And I use only single module, So I have all the basic depndencies (Engine, UnrealEd, Core)

9

I tried reproducing your problem but I didn’t run into the same issues. The next thing I’d suggest trying is to remove the macros I suggested earlier and replace struct FTimerHandle with struct ENGINE_API FTimerHandle inside TimerManager.h.

10

Unfortunetly I’m still at the point when started:

AREffectStatics.h(91): error : In AREffectStatics: Unrecognized type 'FTimerHandle'
11

I noticed that’s the same line number as your previous error that didn’t have ‘#include “timermanager.h”’. Can you confirm that you’re still including timermanager.h at the top of your header file?

12

Yes, I still have it included.