EM_Task/CoreUObject/Private/UObject/PropertySoftObjectPtr.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "UObject/SoftObjectPtr.h"
#include "UObject/PropertyPortFlags.h"
#include "UObject/UnrealType.h"
#include "UObject/LinkerLoad.h"

/*-----------------------------------------------------------------------------
        FSoftObjectProperty.
-----------------------------------------------------------------------------*/
IMPLEMENT_FIELD(FSoftObjectProperty)

FString FSoftObjectProperty::GetCPPTypeCustom(FString* ExtendedTypeText, uint32 CPPExportFlags, const FString& InnerNativeTypeName) const
{
    ensure(!InnerNativeTypeName.IsEmpty());
    return FString::Printf(TEXT("TSoftObjectPtr<%s>"), *InnerNativeTypeName);
}
FString FSoftObjectProperty::GetCPPMacroType(FString& ExtendedTypeText) const
{
    ExtendedTypeText = FString::Printf(TEXT("TSoftObjectPtr<%s%s>"), PropertyClass->GetPrefixCPP(), *PropertyClass->GetName());
    return TEXT("SOFTOBJECT");
}

FString FSoftObjectProperty::GetCPPTypeForwardDeclaration() const
{
    return FString::Printf(TEXT("class %s%s;"), PropertyClass->GetPrefixCPP(), *PropertyClass->GetName());
}

FName FSoftObjectProperty::GetID() const
{
    // SoftClass shares the same tag, they are binary compatible
    return NAME_SoftObjectProperty;
}

// this is always shallow, can't see that we would want it any other way
bool FSoftObjectProperty::Identical(const void* A, const void* B, uint32 PortFlags) const
{
    FSoftObjectPtr ObjectA = A ? *((FSoftObjectPtr*)A) : FSoftObjectPtr();
    FSoftObjectPtr ObjectB = B ? *((FSoftObjectPtr*)B) : FSoftObjectPtr();

    return ObjectA.GetUniqueID() == ObjectB.GetUniqueID();
}

void FSoftObjectProperty::SerializeItem(FStructuredArchive::FSlot Slot, void* Value, void const* Defaults) const
{
    FArchive& UnderlyingArchive = Slot.GetUnderlyingArchive();

    // We never serialize our reference while the garbage collector is harvesting references
    // to objects, because we don't want soft object pointers to keep objects from being garbage collected
    // Allow persistent archives so they can keep track of string references. (e.g. FArchiveSaveTagImports)
    if (!UnderlyingArchive.IsObjectReferenceCollector() || UnderlyingArchive.IsModifyingWeakAndStrongReferences() || UnderlyingArchive.IsPersistent())
    {
        FSoftObjectPtr OldValue = *(FSoftObjectPtr*)Value;
        Slot << *(FSoftObjectPtr*)Value;

        // Check for references to instances of wrong types and null them out
#if !(UE_BUILD_TEST || UE_BUILD_SHIPPING)
        if (UnderlyingArchive.IsLoading() || UnderlyingArchive.IsModifyingWeakAndStrongReferences())
        {
            if (OldValue.GetUniqueID() != ((FSoftObjectPtr*)Value)->GetUniqueID())
            {
                CheckValidObject(Value);
            }
        }
#endif
    }
    else
    {
        // TODO: This isn't correct, but it keeps binary serialization happy. We should ALWAYS be serializing the pointer
        // to the archive in this function, and allowing the underlying archive to ignore it if necessary
        Slot.EnterStream();
    }
}

bool FSoftObjectProperty::NetSerializeItem(FArchive& Ar, UPackageMap* Map, void* Data, TArray<uint8>* MetaData) const
{
    // Serialize directly, will use FBitWriter/Reader
    Ar << *(FSoftObjectPtr*)Data;

    return true;
}

void FSoftObjectProperty::ExportTextItem(FString& ValueStr, const void* PropertyValue, const void* DefaultValue, UObject* Parent, int32 PortFlags, UObject* ExportRootScope) const
{
    FSoftObjectPtr& SoftObjectPtr = *(FSoftObjectPtr*)PropertyValue;

    FSoftObjectPath SoftObjectPath;
    UObject* Object = SoftObjectPtr.Get();

    if (Object)
    {
        // Use object in case name has changed.
        SoftObjectPath = FSoftObjectPath(Object);
    }
    else
    {
        SoftObjectPath = SoftObjectPtr.GetUniqueID();
    }

    if (0 != (PortFlags & PPF_ExportCpp))
    {
        ValueStr += FString::Printf(TEXT("FSoftObjectPath(TEXT(\"%s\"))"), *SoftObjectPath.ToString().ReplaceCharWithEscapedChar());
        return;
    }

    SoftObjectPath.ExportTextItem(ValueStr, SoftObjectPath, Parent, PortFlags, ExportRootScope);
}

const TCHAR* FSoftObjectProperty::ImportText_Internal(const TCHAR* InBuffer, void* Data, int32 PortFlags, UObject* Parent, FOutputDevice* ErrorText) const
{
    FSoftObjectPtr& SoftObjectPtr = *(FSoftObjectPtr*)Data;

    FSoftObjectPath SoftObjectPath;

    bool bImportTextSuccess = false;
#if WITH_EDITOR
    if (HasAnyPropertyFlags(CPF_EditorOnly))
    {
        FSoftObjectPathSerializationScope SerializationScope(NAME_None, NAME_None, ESoftObjectPathCollectType::EditorOnlyCollect, ESoftObjectPathSerializeType::AlwaysSerialize);
        bImportTextSuccess = SoftObjectPath.ImportTextItem(InBuffer, PortFlags, Parent, ErrorText, GetLinker());
    }
    else
#endif  // WITH_EDITOR
    {
        bImportTextSuccess = SoftObjectPath.ImportTextItem(InBuffer, PortFlags, Parent, ErrorText, GetLinker());
    }

    if (bImportTextSuccess)
    {
        SoftObjectPtr = SoftObjectPath;
        return InBuffer;
    }

    else
    {
        SoftObjectPtr = nullptr;
        return nullptr;
    }
}

EConvertFromTypeResult FSoftObjectProperty::ConvertFromType(const FPropertyTag& Tag, FStructuredArchive::FSlot Slot, uint8* Data, UStruct* DefaultsStruct)
{
    static FName NAME_AssetObjectProperty  = "AssetObjectProperty";
    static FName NAME_SoftObjectPath       = "SoftObjectPath";
    static FName NAME_SoftClassPath        = "SoftClassPath";
    static FName NAME_StringAssetReference = "StringAssetReference";
    static FName NAME_StringClassReference = "StringClassReference";

    FArchive& Archive                      = Slot.GetUnderlyingArchive();

    if (Tag.Type == NAME_AssetObjectProperty)
    {
        // Old name of soft object property, serialize normally
        uint8* DestAddress = ContainerPtrToValuePtr<uint8>(Data, Tag.ArrayIndex);

        Tag.SerializeTaggedProperty(Slot, this, DestAddress, nullptr);

        if (Archive.IsCriticalError())
        {
            return EConvertFromTypeResult::CannotConvert;
        }

        return EConvertFromTypeResult::Converted;
    }
    else if (Tag.Type == NAME_ObjectProperty)
    {
        // This property used to be a raw FObjectProperty Foo* but is now a TSoftObjectPtr<Foo>;
        // Serialize from mismatched tag directly into the FSoftObjectPtr's soft object path to ensure that the delegates needed for cooking
        // are fired
        FSoftObjectPtr* PropertyValue = GetPropertyValuePtr_InContainer(Data, Tag.ArrayIndex);
        check(PropertyValue);

        return PropertyValue->GetUniqueID().SerializeFromMismatchedTag(Tag, Slot) ? EConvertFromTypeResult::Converted : EConvertFromTypeResult::UseSerializeItem;
    }
    else if (Tag.Type == NAME_StructProperty && (Tag.StructName == NAME_SoftObjectPath || Tag.StructName == NAME_SoftClassPath || Tag.StructName == NAME_StringAssetReference || Tag.StructName == NAME_StringClassReference))
    {
        // This property used to be a FSoftObjectPath but is now a TSoftObjectPtr<Foo>
        FSoftObjectPath PreviousValue;
        // explicitly call Serialize to ensure that the various delegates needed for cooking are fired
        PreviousValue.Serialize(Slot);

        // now copy the value into the object's address space
        FSoftObjectPtr PreviousValueSoftObjectPtr;
        PreviousValueSoftObjectPtr = PreviousValue;
        SetPropertyValue_InContainer(Data, PreviousValueSoftObjectPtr, Tag.ArrayIndex);

        return EConvertFromTypeResult::Converted;
    }

    return EConvertFromTypeResult::UseSerializeItem;
}

UObject* FSoftObjectProperty::LoadObjectPropertyValue(const void* PropertyValueAddress) const
{
    return GetPropertyValue(PropertyValueAddress).LoadSynchronous();
}

UObject* FSoftObjectProperty::GetObjectPropertyValue(const void* PropertyValueAddress) const
{
    return GetPropertyValue(PropertyValueAddress).Get();
}

void FSoftObjectProperty::SetObjectPropertyValue(void* PropertyValueAddress, UObject* Value) const
{
    SetPropertyValue(PropertyValueAddress, TCppType(Value));
}

bool FSoftObjectProperty::AllowCrossLevel() const
{
    return true;
}

uint32 FSoftObjectProperty::GetValueTypeHashInternal(const void* Src) const
{
    return GetTypeHash(GetPropertyValue(Src));
}

void FSoftObjectProperty::CopySingleValueToScriptVM(void* Dest, void const* Src) const
{
    CopySingleValue(Dest, Src);
}

void FSoftObjectProperty::CopyCompleteValueToScriptVM(void* Dest, void const* Src) const
{
    CopyCompleteValue(Dest, Src);
}

void FSoftObjectProperty::CopySingleValueFromScriptVM(void* Dest, void const* Src) const
{
    CopySingleValue(Dest, Src);
}

void FSoftObjectProperty::CopyCompleteValueFromScriptVM(void* Dest, void const* Src) const
{
    CopyCompleteValue(Dest, Src);
}