# TMap with USTRUCT(FName wrapper) as key displays unusable UI in Details panel

**URL:** <https://forums.unrealengine.com/t/tmap-with-ustruct-fname-wrapper-as-key-displays-unusable-ui-in-details-panel/2700316>\
**Category:** C++\
**Tags:** details-panel, tmap, unreal-engine, question\
**Created:** [February 17, 2026, 3:42pm UTC](https://forums.unrealengine.com/t/tmap-with-ustruct-fname-wrapper-as-key-displays-unusable-ui-in-details-panel/2700316 "2026-02-17T15:42:35Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![koromire1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@koromire1](https://forums.unrealengine.com/u/koromire1)\
**Post date:** [February 17, 2026, 3:42pm UTC](https://forums.unrealengine.com/t/tmap-with-ustruct-fname-wrapper-as-key-displays-unusable-ui-in-details-panel/2700316/1 "2026-02-17T15:42:35Z")

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Hello,

I am trying to keep strong typing in C++ while still having a usable DataAsset workflow in the editor.

I have a simple goal:

I want a TMap that uses a strongly typed FName to behave exactly like a normal TMap\<FName, FName\> in the Details panel.

Right now these two properties behave very differently in the editor:

TMap\<FName, FName\> → nice inline editable key field (works perfectly)

TMap\<FGameIdDialogueScene, FName\> → nested struct UI that makes authoring the map extremely painful when it grows :

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/f/2/1/f21720451f96c5009e75a49ce6c9d67bb259cf66.png)

Here is the code:

```auto
UCLASS(BlueprintType)
class MYGAME_API UTMapTestDataAsset : public UDataAsset
{
  GENERATED_BODY()

public:
  UPROPERTY(EditDefaultsOnly)
  TMap<FGameIdDialogueScene, FName> mMapWithFGameIdDialogueSceneAsKey{};

  UPROPERTY(EditDefaultsOnly)
  TMap<FName, FName> mMapWithFNameAsKey{};
};

USTRUCT(BlueprintType)
struct MYGAME_API FGameIdDialogueScene
{
  GENERATED_BODY()

public:
  FGameIdDialogueScene() = default;

  explicit FGameIdDialogueScene(const FName InValue) : mValue(InValue) {}

  bool IsValid() const { return mValue != NAME_None; }

  friend bool operator==(const FGameIdDialogueScene& A, const FGameIdDialogueScene& B)
  {
	  return A.mValue == B.mValue;
  }

  friend uint32 GetTypeHash(const FGameIdDialogueScene& Id)
  {
	  return GetTypeHash(Id.mValue);
  }

  UPROPERTY(EditAnywhere, BlueprintReadWrite)
  FName mValue{ NAME_None };

  static const FGameIdDialogueScene None;
};

```

For now the only workaround I found is to use a DataTable and use the row name as the value to initialize my ID type. It technically preserves the strong typing in C++, but it forces me to maintain a DataTable and parse it every time, which makes the workflow quite painful and significantly complicates my data structures but its easier to read… So it really feels like a very hacky solution rather than a proper one…

I know that in theory this should be solvable using a Details / Property customization.

The problem is that I already tried to implement one and spent about two full days on it, and I never managed to get a reliable result for a TMap key. Sometimes the text just disappear, sometime the TMap is not even visible…

So at this point I’m not sure whether:

- I misunderstood how the property system is supposed to be extended

- or whether TMap keys based on a USTRUCT wrapping an FName simply cannot be made to behave like a native FNameProperty

What I’d really like to know is:

- Has anyone actually succeeded in making a USTRUCT that wraps an FName display exactly like an FName when used as a TMap key in the Details panel?

And if it is possible:

- Is this something that must be implemented separately for each struct type, or is there a generic way to support multiple “strong ID” types (for example several FGameId-like structs) so they all render as a single FName field?

Basically I’m completely open to the idea that I did it wrong, but after two days of attempts I need to know if I’m missing a specific hook, or if the engine just doesn’t support this use case and the behavior I’m seeing is expected.

Thanks for any guidance.

---

<div class="post-metadata">

**Author:** ![Vahab](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/vahab/32/1148756_2.png) [@Vahab](https://forums.unrealengine.com/u/Vahab)\
**Post date:** [February 20, 2026, 3:19pm UTC](https://forums.unrealengine.com/t/tmap-with-ustruct-fname-wrapper-as-key-displays-unusable-ui-in-details-panel/2700316/2 "2026-02-20T15:19:56Z")

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It is the default behavior, even when using internal structs like FGameplayTag. You must use the **`ForceInlineRow`** meta specifier.

Here is an example I tested with and without it:

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/e/9/7e9c19afe130a560b92d3daf69d658311a1f5b83.png)

---

<div class="post-metadata">

**Author:** ![koromire1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@koromire1](https://forums.unrealengine.com/u/koromire1)\
**Post date:** [February 27, 2026, 5:50pm UTC](https://forums.unrealengine.com/t/tmap-with-ustruct-fname-wrapper-as-key-displays-unusable-ui-in-details-panel/2700316/3 "2026-02-27T17:50:30Z")

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Thanks a lot for the suggestion, `ForceInlineRow` does help.

Unfortunately, as soon as I tried switching the map value from `FName` to a `USTRUCT`, the problem came back.

- `TMap<FGameIdDialogueScene, FName>` → looks good with `ForceInlineRow`

- `TMap<FGameIdDialogueScene, FMyStruct>` → the nested struct UI returns, and authoring becomes painful again