Fix Bugs In Doc.

General Feedback & Requests
1

Hi all concerned EU4 citizens. I am a new community member and I wanted to try out the programming features of EU4.

I stumbled upon this Official EU4 programming tutorial

of how to create a class in C++ code in UE4.

There are two bugs either in my understanding of basic tutorials. or the tutorial itself.

Sphere1->OnComponentBeginOverlap.AddDynamic(this, &ALightSwitchCodeOnly::OnOverlap); // set up a notification for when this component overlaps something
Sphere1->OnComponentEndOverlap.AddDynamic(this, &ALightSwitchCodeOnly::OnOverlap); // set up a notification for when this component overlaps something

these lines of code do not compile. And no such thing as AddDynamic() functions are visible to me that exists. As a matter of fact __inner_AddDynamic() apparently exists but I dont know how to use it.

Nothing works until I put all the members of the class in the public: zone. I have broke my head over and over until I found how to actually have these components visible in the Editor. No mention or of the public: necessity in the document ofcoarse.

Could the documentation page be updated with current version of coding please? I am in a rather hurry to learn UE4 coding concepts, and I dont want to have these pitfalls spread all over the place.

2

Can you please post the error that you are getting, as this is still the correct usage even as of 4.5. I am using AddDynamic throughout my game without any issues.

3

Header code

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

#pragma once

#include “GameFramework/Actor.h”
#include “LightSwitchCodeOnly.generated.h”

/**
*
*/
UCLASS()
class TUTORIALCLASSCREATE_API ALightSwitchCodeOnly : public AActor
{
GENERATED_UCLASS_BODY()

	/** point light component */
	UPROPERTY(VisibleAnywhere, Category = "Switch Components")
	TSubobjectPtr<UPointLightComponent> PointLight1;

/** sphere component */
UPROPERTY(VisibleAnywhere, Category = "Switch Components")
	TSubobjectPtr<USphereComponent> Sphere1;

/** called when something overlaps the sphere component */
UFUNCTION()
	void OnOverlap(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);

/** the desired intensity for the light */
UPROPERTY(VisibleAnywhere, Category = "Switch Variables")
	float DesiredIntensity;

};

cpp code

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

#include “TutorialClassCreate.h”
#include “LightSwitchCodeOnly.h”

ALightSwitchCodeOnly::ALightSwitchCodeOnly(const FObjectInitializer& ObjectInitializer)
: Super(ObjectInitializer)
{
DesiredIntensity = 3000.0f;

PointLight1 = ObjectInitializer.CreateDefaultSubobject<UPointLightComponent>(this, "PointLight1");
PointLight1->Intensity = DesiredIntensity;
PointLight1->bVisible = true;
RootComponent = PointLight1;

Sphere1 = ObjectInitializer.CreateDefaultSubobject<USphereComponent>(this, TEXT("Sphere1"));
Sphere1->InitSphereRadius(250.0f);
Sphere1->AttachParent = RootComponent;

Sphere1->OnComponentBeginOverlap.AddDynamic(this, &ALightSwitchCodeOnly::OnOverlap);        // set up a notification for when this component overlaps something
Sphere1->OnComponentEndOverlap.AddDynamic(this, &ALightSwitchCodeOnly::OnOverlap);      // set up a notification for when this component overlaps something

}

void ALightSwitchCodeOnly::OnOverlap(AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
{
if (OtherActor && (OtherActor != this) && OtherComp)
{
PointLight1->ToggleVisibility();
}
}

error list

41	IntelliSense: no instance of function template "FComponentBeginOverlapSignature::__Internal_AddDynamic" matches the argument list
        argument types are: (ALightSwitchCodeOnly *, void (ALightSwitchCodeOnly::*)(AActor *OtherActor, UPrimitiveComponent *OtherComp, int32 OtherBodyIndex), FString)
        object type is: FComponentBeginOverlapSignature	c:\Users\ilia\Documents\Unreal Projects\TutorialClassCreate\Source\TutorialClassCreate\LightSwitchCodeOnly.cpp	21	34	TutorialClassCreate

Error 1 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int C:\Users\ilia\Documents\Unreal Projects\TutorialClassCreate\Source\TutorialClassCreate\LightSwitchCodeOnly.cpp 7 1 TutorialClassCreate

Error 2 error C2143: syntax error : missing ‘,’ before ‘&’ C:\Users\ilia\Documents\Unreal Projects\TutorialClassCreate\Source\TutorialClassCreate\LightSwitchCodeOnly.cpp 7 1 TutorialClassCreate

Error 3 error C2511: ‘ALightSwitchCodeOnly::ALightSwitchCodeOnly(const int)’ : overloaded member function not found in ‘ALightSwitchCodeOnly’ C:\Users\ilia\Documents\Unreal Projects\TutorialClassCreate\Source\TutorialClassCreate\LightSwitchCodeOnly.cpp 8 1 TutorialClassCreate

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there are too many to copy. Basically there are a bunch of things it doesn’t recognize.

Maybe there is Something wrong with ObjectInitializer??? because the template creates something called a PCIP or something like that.

4

Try changing:


void ALightSwitchCodeOnly::OnOverlap(AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)

to


void ALightSwitchCodeOnly::OnOverlap( AActor* Other, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult )

And do the same in the header.

Appears the signature did change since the doc was written.

5

We are aware of the inaccuracies here and plan to have them fixed for the next release.

Thanks for pointing this out!