deprecate_asset_id_invalid.md

---

title: "`AssetId::invalid()` and `AssetId::INVALID_UUID` have been deprecated"
pull_requests: [24392]

---

AssetId::invalid() and AssetId::INVALID_UUID have been deprecated. This is part of an effort to reduce special cases and optimize asset lookups.

If you were using AssetId::invalid() as a null value, the recommended solution is to change your variable to be Option<AssetId> and use None instead of AssetId::invalid().

Before:

struct MyImageResource(AssetId<Image>);

world.insert_resource(MyImageResource(AssetId::invalid());

...

let resource = world.resource::<MyImageResource>()?;
let asset = assets.get(resource.0)?;

After:

struct MyImageResource(Option<AssetId<Image>>);

world.insert_resource(MyImageResource(None));

...

let resource = world.resource::<MyImageResource>()?;
let asset = assets.get(resource.0?)?;

In some cases it may be possible to use AssetId::default() instead. But note that the default ID is not guaranteed to be a null value - an asset can be registered with the default ID.