ActorComponent gets none in blueprint

Development Programming & Scripting Blueprint
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1

Hello everyone,

I have written an UInventoryComponent class which inherits from UActorComponent. I register it to my character in its constructor this way:

Inventory = CreateDefaultSubobject<UInventoryComponent>(TEXT("InventoryComponent"));

InventoryComponent.h:

#pragma once

#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "Item.h"
#include "InventoryItem.h"
#include "InventoryComponent.generated.h"

class AItemActor;

UCLASS(ClassGroup = (Custom), meta = (BlueprintSpawnableComponent))
class RPS_API UInventoryComponent : public UActorComponent
{
	GENERATED_BODY()

public:	
	// Sets default values for this component's properties
	UInventoryComponent();
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Inventory")
	TArray<UInventoryItem*> items;

protected:
	// Called when the game starts
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;
	UFUNCTION(BlueprintCallable)
		void AddItemActor(AItemActor * itemActor);
	UFUNCTION(BlueprintCallable)
	void AddItem(TSubclassOf<UItem> item,int number=1);
	UFUNCTION(BlueprintCallable)
	void DropItem(UInventoryItem *iItem);

	UFUNCTION(BlueprintCallable)
		void RemoveItem(UItem *item);
	UFUNCTION(BlueprintCallable)
		TArray<UInventoryItem*> GetItems(TSubclassOf<UItem> item);
	UFUNCTION(BlueprintCallable)
		int GetItemCount(TSubclassOf<UItem> item);
	UFUNCTION(BlueprintCallable)
		bool HasItem(TSubclassOf<UItem> item);
};

however, when I restart the engine or change my characters c++ class, this Inventory component becomes None in blueprint. It throws error when I try to use it.

The solution I found was to remove the CreateDefaultSubObject line, then compile, then re-add the line again, and compile, and everything works fine. This, as you notice, is a boring process and I believe this is not the expected behavior of the engine. If I add the component from blueprint (not from c++ constructor) I never have any problem.

What may be the solution?
Thanks

2

Did you created blueprint of your character class, or c++ version?

I noticed an issue in blueprints, inherited from custom c++ classes, that when you add/change something to its constructor, you must recreate blueprint asset. It seems that blueprint is not updated with new changes So, I fixed it with not creating blueprints from that classes at all, or creating them only when I sure that it finished.