Interface with UFUNCTION(BlueprintNativeEvent) and implementation problem

Development Programming & Scripting C++
1

Hello, i’m having troubles trying to make an interface with implemented function…

IArchivable.h


#pragma once

#include "Core.h"
#include "UObject/NoExportTypes.h"
#include "Interface.h"

#include "IArchivable.generated.h"

UINTERFACE(BlueprintType)
class A1_API UIArchivable : public UInterface
{
    GENERATED_UINTERFACE_BODY()
};

class A1_API IIArchivable
{
    GENERATED_IINTERFACE_BODY()

public :

    UFUNCTION(BlueprintNativeEvent)
        void ArchiveNecessity(int32 UniqueID);

    virtual void ArchiveNecessity_Implementation(int32 UniqueID) override;
};

IArchivable.cpp


#include "IArchivable.h"

UIArchivable::UIArchivable(const class FObjectInitializer& ObjectInitializer)
    : Super(ObjectInitializer)
{}

void IIArchivable::ArchiveNecessity_Implementation(int32 UniqueID) override
{
    UE_LOG(LogTemp, Warning, TEXT("ArchiveNecessity pushed"));
}

I tryed a lots of things, there is a lot’s of topik and tutorial, i think i tryed all that was possible (even a full clean-build) and i don’t know where is the problem.

What is the working way to write that?
Compiler say that the func is already define in this exemple.

With different changes i can make it can say that “the func is not define” or already have a body… but never “ok it is define one time i accept it.”

There is 0 include of this file somewhere else, it’s a fresh class.

Here is the Generated file if you need it :
[SPOILER]


// Copyright 1998-2018 Epic Games, Inc. All Rights Reserved.
/*===========================================================================
    Generated code exported from UnrealHeaderTool.
    DO NOT modify this manually! Edit the corresponding .h files instead!
===========================================================================*/

#include "UObject/ObjectMacros.h"
#include "UObject/ScriptMacros.h"

PRAGMA_DISABLE_DEPRECATION_WARNINGS
#ifdef A1_IArchivable_generated_h
#error "IArchivable.generated.h already included, missing '#pragma once' in IArchivable.h"
#endif
#define A1_IArchivable_generated_h

#define A2_Source_A1_Public_IArchivable_h_14_RPC_WRAPPERS \
    virtual void ArchiveNecessity_Implementation(int32 UniqueID) {}; \
 \
    DECLARE_FUNCTION(execArchiveNecessity) \
    { \
        P_GET_PROPERTY(UIntProperty,Z_Param_UniqueID); \
        P_FINISH; \
        P_NATIVE_BEGIN; \
        P_THIS->ArchiveNecessity_Implementation(Z_Param_UniqueID); \
        P_NATIVE_END; \
    }


#define A2_Source_A1_Public_IArchivable_h_14_RPC_WRAPPERS_NO_PURE_DECLS \
 \
    DECLARE_FUNCTION(execArchiveNecessity) \
    { \
        P_GET_PROPERTY(UIntProperty,Z_Param_UniqueID); \
        P_FINISH; \
        P_NATIVE_BEGIN; \
        P_THIS->ArchiveNecessity_Implementation(Z_Param_UniqueID); \
        P_NATIVE_END; \
    }


#define A2_Source_A1_Public_IArchivable_h_14_EVENT_PARMS \
    struct IArchivable_eventArchiveNecessity_Parms \
    { \
        int32 UniqueID; \
    };


#define A2_Source_A1_Public_IArchivable_h_14_CALLBACK_WRAPPERS
#define A2_Source_A1_Public_IArchivable_h_14_STANDARD_CONSTRUCTORS \
    /** Standard constructor, called after all reflected properties have been initialized */ \
    NO_API UIArchivable(const FObjectInitializer& ObjectInitializer = FObjectInitializer::Get()); \
    DEFINE_DEFAULT_OBJECT_INITIALIZER_CONSTRUCTOR_CALL(UIArchivable) \
    DECLARE_VTABLE_PTR_HELPER_CTOR(NO_API, UIArchivable); \
DEFINE_VTABLE_PTR_HELPER_CTOR_CALLER(UIArchivable); \
private: \
    /** Private move- and copy-constructors, should never be used */ \
    NO_API UIArchivable(UIArchivable&&); \
    NO_API UIArchivable(const UIArchivable&); \
public:


#define A2_Source_A1_Public_IArchivable_h_14_ENHANCED_CONSTRUCTORS \
    /** Standard constructor, called after all reflected properties have been initialized */ \
    NO_API UIArchivable(const FObjectInitializer& ObjectInitializer = FObjectInitializer::Get()) : Super(ObjectInitializer) { }; \
private: \
    /** Private move- and copy-constructors, should never be used */ \
    NO_API UIArchivable(UIArchivable&&); \
    NO_API UIArchivable(const UIArchivable&); \
public: \
    DECLARE_VTABLE_PTR_HELPER_CTOR(NO_API, UIArchivable); \
DEFINE_VTABLE_PTR_HELPER_CTOR_CALLER(UIArchivable); \
    DEFINE_DEFAULT_OBJECT_INITIALIZER_CONSTRUCTOR_CALL(UIArchivable)


#define A2_Source_A1_Public_IArchivable_h_14_GENERATED_UINTERFACE_BODY() \
private: \
    static void StaticRegisterNativesUIArchivable(); \
    friend struct Z_Construct_UClass_UIArchivable_Statics; \
public: \
    DECLARE_CLASS(UIArchivable, UInterface, COMPILED_IN_FLAGS(CLASS_Abstract | CLASS_Interface), CASTCLASS_None, TEXT("/Script/A1"), NO_API) \
    DECLARE_SERIALIZER(UIArchivable)


#define A2_Source_A1_Public_IArchivable_h_14_GENERATED_BODY_LEGACY \
        PRAGMA_DISABLE_DEPRECATION_WARNINGS \
    A2_Source_A1_Public_IArchivable_h_14_GENERATED_UINTERFACE_BODY() \
    A2_Source_A1_Public_IArchivable_h_14_STANDARD_CONSTRUCTORS \
    PRAGMA_ENABLE_DEPRECATION_WARNINGS


#define A2_Source_A1_Public_IArchivable_h_14_GENERATED_BODY \
    PRAGMA_DISABLE_DEPRECATION_WARNINGS \
    A2_Source_A1_Public_IArchivable_h_14_GENERATED_UINTERFACE_BODY() \
    A2_Source_A1_Public_IArchivable_h_14_ENHANCED_CONSTRUCTORS \
private: \
    PRAGMA_ENABLE_DEPRECATION_WARNINGS


#define A2_Source_A1_Public_IArchivable_h_14_INCLASS_IINTERFACE_NO_PURE_DECLS \
protected: \
    virtual ~IIArchivable() {} \
public: \
    typedef UIArchivable UClassType; \
    typedef IIArchivable ThisClass; \
    static void Execute_ArchiveNecessity(UObject* O, int32 UniqueID); \
    virtual UObject* _getUObject() const { check(0 && "Missing required implementation."); return nullptr; }


#define A2_Source_A1_Public_IArchivable_h_14_INCLASS_IINTERFACE \
protected: \
    virtual ~IIArchivable() {} \
public: \
    typedef UIArchivable UClassType; \
    typedef IIArchivable ThisClass; \
    static void Execute_ArchiveNecessity(UObject* O, int32 UniqueID); \
    virtual UObject* _getUObject() const { check(0 && "Missing required implementation."); return nullptr; }


#define A2_Source_A1_Public_IArchivable_h_11_PROLOG \
    A2_Source_A1_Public_IArchivable_h_14_EVENT_PARMS


#define A2_Source_A1_Public_IArchivable_h_19_GENERATED_BODY_LEGACY \
PRAGMA_DISABLE_DEPRECATION_WARNINGS \
public: \
    A2_Source_A1_Public_IArchivable_h_14_RPC_WRAPPERS \
    A2_Source_A1_Public_IArchivable_h_14_CALLBACK_WRAPPERS \
    A2_Source_A1_Public_IArchivable_h_14_INCLASS_IINTERFACE \
public: \
PRAGMA_ENABLE_DEPRECATION_WARNINGS


#define A2_Source_A1_Public_IArchivable_h_19_GENERATED_BODY \
PRAGMA_DISABLE_DEPRECATION_WARNINGS \
public: \
    A2_Source_A1_Public_IArchivable_h_14_RPC_WRAPPERS_NO_PURE_DECLS \
    A2_Source_A1_Public_IArchivable_h_14_CALLBACK_WRAPPERS \
    A2_Source_A1_Public_IArchivable_h_14_INCLASS_IINTERFACE_NO_PURE_DECLS \
private: \
PRAGMA_ENABLE_DEPRECATION_WARNINGS


#undef CURRENT_FILE_ID
#define CURRENT_FILE_ID A2_Source_A1_Public_IArchivable_h


PRAGMA_ENABLE_DEPRECATION_WARNINGS

[/SPOILER]

2

Just want you to know that if i change this line :


 
 GENERATED_IINTERFACE_BODY()

to


  
 GENERATED_BODY()

it compile, but when adding the interface to a Blueprint, the function is not avalaible.