I’ve got a custom asset, which I’ve made a custom factory for. The actual file is just text, so I load it, do some processing and save whatever data I need in the asset. I’ve also implemented an FReimportHandler so that the asset can be re-imported.
The factory is like so:
// Copyright 2018 David Colson. All Rights Reserved.
#include "StoryAssetFactory.h"
#include "HAL/PlatformFilemanager.h"
#include "Misc/Paths.h"
#include "Interfaces/IPluginManager.h"
#include "InkEditor.h"
#include "StoryAsset.h"
#include "InkCompiler.h"
#include "Misc/FileHelper.h"
#include "EditorFramework/AssetImportData.h"
////////////////////////////////////////////////////////
UStoryAssetFactory::UStoryAssetFactory()
{
Formats.Add(FString(TEXT("ink;")) + NSLOCTEXT("UTextAssetFactory", "FormatTxt", "Ink Story File").ToString());
Formats.Add(FString(TEXT("json;")) + NSLOCTEXT("UTextAssetFactory", "FormatTxt", "Compiled Ink Story File").ToString());
SupportedClass = UStoryAsset::StaticClass();
bCreateNew = false;
bEditorImport = true;
}
////////////////////////////////////////////////////////
bool UStoryAssetFactory::FactoryCanImport(const FString & Filename)
{
if (Filename.EndsWith("ink.json") || Filename.EndsWith("ink"))
{
return true;
}
return false;
}
////////////////////////////////////////////////////////
UObject * UStoryAssetFactory::FactoryCreateFile(UClass * InClass, UObject * InParent, FName InName, EObjectFlags Flags, const FString & Filename, const TCHAR * Parms, FFeedbackContext * Warn, bool & bOutOperationCanceled)
{
FString FileExtension = FPaths::GetExtension(Filename);
GEditor->GetEditorSubsystem<UImportSubsystem>()->BroadcastAssetPreImport(this, InClass, InParent, InName, *FileExtension);
UStoryAsset* NewStory = nullptr;
FString FileContents;
if (Filename.EndsWith("ink.json"))
{
// This is precompiled, just save the contents
if (FFileHelper::LoadFileToString(FileContents, *Filename))
{
FString Assetname = InName.ToString();
NewStory = NewObject<UStoryAsset>(InParent, InClass, FName(*(Assetname.LeftChop(4))), Flags);
NewStory->CompiledStory = FileContents;
NewStory->AssetImportData->Update(Filename);
}
bOutOperationCanceled = false;
GEditor->GetEditorSubsystem<UImportSubsystem>()->BroadcastAssetPostImport(this, NewStory);
return NewStory;
}
else if (Filename.EndsWith("ink"))
{
if (FFileHelper::LoadFileToString(FileContents, *Filename))
{
// Make new inkcompiler object
UInkCompiler* compiler = UInkCompiler::NewInkCompiler(FileContents, Filename);
FString compiledStory = compiler->CompileToJson();
// Run the function
NewStory = NewObject<UStoryAsset>(InParent, InClass, InName, Flags);
NewStory->CompiledStory = compiledStory;
NewStory->AssetImportData->Update(Filename);
bOutOperationCanceled = false;
// profit
GEditor->GetEditorSubsystem<UImportSubsystem>()->BroadcastAssetPostImport(this, NewStory);
return NewStory;
}
}
GEditor->GetEditorSubsystem<UImportSubsystem>()->BroadcastAssetPostImport(this, nullptr);
return nullptr;
}
bool UStoryAssetFactory::CanReimport(UObject* Obj, TArray<FString>& OutFilenames)
{
UStoryAsset* StoryAsset = Cast<UStoryAsset>(Obj);
if (StoryAsset && StoryAsset->AssetImportData)
{
StoryAsset->AssetImportData->ExtractFilenames(OutFilenames);
return true;
}
return false;
}
void UStoryAssetFactory::SetReimportPaths(UObject* Obj, const TArray<FString>& NewReimportPaths)
{
UStoryAsset* StoryAsset = Cast<UStoryAsset>(Obj);
if (StoryAsset && ensure(NewReimportPaths.Num() == 1))
{
StoryAsset->AssetImportData->UpdateFilenameOnly(NewReimportPaths[0]);
}
}
EReimportResult::Type UStoryAssetFactory::Reimport(UObject* Obj)
{
UStoryAsset* StoryAsset = Cast<UStoryAsset>(Obj);
if (StoryAsset != nullptr)
{
if (StoryAsset->AssetImportData)
{
bool bOperationCancelled = false;
if (ImportObject(StoryAsset->GetClass(), StoryAsset->GetOuter(), *StoryAsset->GetName(), RF_Public | RF_Standalone, StoryAsset->AssetImportData->GetFirstFilename(), nullptr, bOperationCancelled) != nullptr)
{
return EReimportResult::Succeeded;
}
}
}
return EReimportResult::Failed;
}
int32 UStoryAssetFactory::GetPriority() const
{
return ImportPriority;
}
The issue is, if you drop the source file into the Content folder of your game. It will auto-reimport correctly. But if you import a file not inside the content folder, it won’t reimport. And the context menu options in the Content Browser are missing for reimporting:
How can I get it to have the reimport options that you’d find on a texture for example?
