Creating UE4 events, opposed to c++ _event?

Belven · March 17, 2015, 7:23am

Hey, so I’ve got to the point where I need to be able to create listeners and notifiers within a lot of my classes. Currently I’m use c++ to do this with _raise and _event:

github.com

belven/The_Battle_Of_Maldon/blob/master/The_Battle_Of_Maldon/Public/EventSource.h


#pragma once
#include <stdio.h>
#include "AttackAction.h"
#include "MoveAction.h"
#include "DefenseAction.h"
#include "Damage.h"

[event_source(native)]
class EventSource {
public:
	__event bool AttackActionEvent(AttackAction* action);
	__event bool DefenseActionEvent(DefenseAction* action);
	__event bool MoveActionEvent(MoveAction* action);
	//__event bool LivingEntityDamageEvent(Damage* damage);
};

github.com

belven/The_Battle_Of_Maldon/blob/master/The_Battle_Of_Maldon/Public/EventReceiver.h

#pragma once
#include <stdio.h>
#include "EventSource.h"
#include "AttackAction.h"
#include "MoveAction.h"
#include "DefenseAction.h"
#include "Damage.h"

[event_receiver(native)]
class EventReceiver {
public:
	bool AttackActionEvent(AttackAction* action) {

		return true;
	}

	bool MoveActionEvent(MoveAction* action) {

		return true;
	}

This file has been truncated. show original

It’s easy to use but I’d like to use UE4s way of doing this as well, providing that it will work in c++ just as well as blueprints.

I’ve noticed this:

CollisionComp->OnComponentHit.AddDynamic(this, &AThe_Battle_Of_MaldonProjectile::OnHit); // set up a notification for when this component hits something blocking

which appears to be like this in my code:

__hook(&EventSource::AttackActionEvent, pSource, &EventReceiver::AttackActionEvent);

Where the method of OnComponentHit, the notifier/event, is run from the CollisionComp and also passed into the method OnHit, the listner, of AThe_Battle_Of_MaldonProjectile.

What what I have to do to set this up? Does ‘AddDynamic’, automatically hook OnComponentHit to OnHit or do I need to change something in OnComponentHit?

staticvoidlol · March 17, 2015, 10:26am

These links should be helpful:

Official Documentation

Forum Post

Belven · March 17, 2015, 4:47pm

Thanks, I’ll look into it. lots of stuff to do for such a simple thing…

Belven · March 17, 2015, 5:40pm

So i’ve got the idea but the compiler won’t compile. All I have is:

DECLARE_DELEGATE_OneParam(SuppliesGivenEvent, ASupply*);

UCLASS(Blueprintable, BlueprintType)
class THE_BATTLE_OF_MALDON_API AVillageVolume : public ABaseVolume
{

…
UPROPERTY(BlueprintAssignable, Category = “Events”)

	SuppliesGivenEvent OnSuppliesGivenEvent;

}

It just doesn’t know what SuppliesGivenEvent is, Unrecognized type ‘SuppliesGivenEvent’ etc?