TArray<> property not visible in derived blueprint class.

Development Programming & Scripting
, ,
1

I have two classes QuestBase and QuestCondition.


#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "QuestBase.generated.h"

UCLASS(Blueprintable)
class QUESTS_API AQuestBase : public AActor
{
	GENERATED_BODY()
	
public:	
	AQuestBase();

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Quest)
	TArray <class UQuestCondition*> QuestConditions;

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Quest)
	TArray <class UObject*> UObjectQuestConditions;

};


#include "CoreMinimal.h"
#include "UObject/NoExportTypes.h"
#include "QuestCondition.generated.h"

/**
 * 
 */
UCLASS(Blueprintable)
class QUESTS_API UQuestCondition : public UObject
{
	GENERATED_BODY()

public:
	UQuestCondition();
	
};

Based on those two I created their child classes in blueprints.

I want to add one or more QuestConditions to the BP_Quest_1 but I can’t do it if they derive from UQuestCondition;

UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Quest)

TArray <class UQuestCondition*> QuestConditions;

if I change TArray <class UQuestCondition*> to something else like UObject or AActor then it works but not when it`s a class that derive from Uobject.

Am I missing some macro here?

Socksnotdelivered
Socksnotdelivered1438×581 153 KB

2

I’ve found sort of solution.
replace
```
TArray <class UQuestCondition*> QuestConditions;

with
	```
TArray <TSubclassOf<class UQuestCondition>> QuestConditions;

but I still would like to know why first case doesn’t work, because If I use class that derives from AActor or Character it works.

3

The syntax class UQuestCondition* does not equate to a class type variable. It is essentially equivalent to UQuestCondition* which means it’s a pointer to an instance of UQuestCondition object. If you had an UQuestCondition object constructed somewhere it the world/editor, it would probably show up in the picker. Generally, you should never set object references in class defaults. The only case where setting object references in a details panel is valid, is when you place an actor in the level and edit its properties to reference another actor in the level.

Class references are of type UClass*, and TSubclassOf is a wrapper for UClass* designed to enforce specific sub-classes.

It also works with UObject* because an UClass* is actually a child of UObject* under the hood, but it’s a crapshoot, and you’ll have to cast to UClass* everytime you want to use it.

Using TSubclassOf<UQuestCondition> is the only proper solution here.

4

Thanku you for this explanation.