# Bevy_save
[![][img_bevy]][bevy] [![][img_version]][crates] [![][img_doc]][doc] [![][img_license]][license] [![][img_tracking]][tracking] [![][img_downloads]][crates]
A framework for saving and loading application state in Bevy.
<https://user-images.githubusercontent.com/29737477/234151375-4c561c53-a8f4-4bfe-a5e7-b69af883bf65.mp4>
## Features
### Save file management
`bevy_save` automatically uses your app's workspace name to create a unique, permanent save location in the correct place for [any platform](#platforms) it can run on.
By default, [`World::save()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldPathwayExt.html#tymethod.save) and [`World::load()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldPathwayExt.html#tymethod.load) uses the managed save file location to save and load your application state, handling all serialization and deserialization for you.
#### Save directory location
With the default [`FileIO`] backend, your save directory is managed for you.
[`WORKSPACE`] is the name of your project's workspace (parent folder) name.
| `C:\Users\%USERNAME%\AppData\Local\WORKSPACE\saves` | `~/.local/share/WORKSPACE/saves` | `~/Library/Application Support/WORKSPACE/saves` |
On WASM, snapshots are saved to [`LocalStorage`], with the key `WORKSPACE.KEY`.
### Reflection-based Snapshots
`bevy_save` is not just about save files, it is about total control over application state.
With the `"reflect"` feature enabled, this crate introduces a snapshot type which may be used directly:
- [`Snapshot`] is a serializable snapshot of all saveable resources, entities, and components.
Or via the [`World`] extension method [`WorldPathwayExt`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldPathwayExt.html) and [`WorldCheckpointExt`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldCheckpointExt.html):
- [`World::capture()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldPathwayExt.html#tymethod.capture) captures a snapshot of the current application state, including resources.
- [`World::apply()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldPathwayExt.html#tymethod.apply) applies a snapshot to the [`World`].
#### Versioning and Migrations
Applications can change over the history of development. Users expect that saves created in an older version will continue to work in newer versions.
`bevy_save` provides support for reflection-based migrations with the [`Migrate`] trait:
```rust,ignore
// `#[reflect(Migrate)]` registers `ReflectMigrate` with the `TypeRegistry`
// This allows `Snapshot`s to save the type version and apply migrations automatically
#[derive(Reflect, Component, Debug, PartialEq)]
#[type_path = "migrate"]
#[type_name = "Position"]
#[reflect(Component, Migrate)]
struct Position {
xyz: (f32, f32, f32),
}
// The `Migrate` trait allows you to define a `Migrator`
// which will step the upgrade through each version
impl Migrate for Position {
fn migrator() -> Migrator<Self> {
#[derive(Reflect)]
#[type_path = "migrate"]
#[type_name = "Pos"]
struct PosV0_1 {
x: f32,
y: f32,
}
Migrator::new::<PosV0_1>("0.1.0")
.version("0.2.0", |v1| {
// Changing type paths and type names is supported
#[derive(Reflect)]
#[type_path = "migrate"]
#[type_name = "Position"]
struct PosV0_2 {
x: f32,
y: f32,
}
Some(PosV0_2 { x: v1.x, y: v1.y })
})
.version("0.3.0", |v2| {
#[derive(Reflect)]
#[type_path = "migrate"]
#[type_name = "Position"]
struct PosV0_3 {
x: f32,
y: f32,
z: f32,
}
// Fields can be re-mapped from version to version, added, or removed
Some(PosV0_3 {
x: v2.x,
y: v2.y,
z: 0.0,
})
})
// The final version will represent the current layout
.version("0.4.0", |v2| {
Some(Self {
xyz: (v2.x, v2.y, v2.z),
})
})
}
}
```
#### Rollbacks and checkpoints
With the `"checkpoints"` feature enabled, this crate provides methods for creating checkpoints which are ordered and can be rolled back / forwards through.
- [`World::checkpoint()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldCheckpointExt.html#tymethod.checkpoint) captures a snapshot for later rollback / rollforward.
- [`World::rollback()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.WorldCheckpointExt.html#tymethod.rollback) rolls the application state backwards or forwards through any checkpoints you have created.
The [`Checkpoints`] resource also gives you fine-tuned control of the currently stored rollback checkpoints.
#### Type registration
No special traits or NewTypes necessary, `bevy_save` takes full advantage of Bevy's built-in reflection.
As long as the type implements [`Reflect`], it can be registered and used with `bevy_save`.
`bevy_save` provides extension traits for [`App`] allowing you to do so.
- [`App.init_pipeline::<P>()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.AppPipelineExt.html#tymethod.init_pipeline) initializes a [`Pipeline`] for use with save / load.
- [`App.allow_checkpoint::<T>()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.AppCheckpointExt.html#tymethod.allow_checkpoint) allows a type to roll back.
- [`App.deny_checkpoint::<T>()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.AppCheckpointExt.html#tymethod.deny_checkpoint) denies a type from rolling back.
#### Pipeline
The [`Pipeline`] trait allows you to use multiple different configurations of [`Backend`] and [`Format`] in the same [`App`].
Using [`Pipeline`] also lets you re-use [`Snapshot`] appliers and builders.
```rust,ignore
struct HeirarchyPipeline;
impl Pipeline for HeirarchyPipeline {
type Backend = DefaultDebugBackend;
type Format = DefaultDebugFormat;
type Key<'a> = &'a str;
fn key(&self) -> Self::Key<'_> {
"examples/saves/heirarchy"
}
fn capture(&self, builder: BuilderRef) -> Snapshot {
builder
.extract_entities_matching(|e| e.contains::<Player>() || e.contains::<Head>())
.build()
}
fn apply(&self, world: &mut World, snapshot: &Snapshot) -> Result<(), bevy_save::Error> {
snapshot
.applier(world)
.despawn::<Or<(With<Player>, With<Head>)>>()
.apply()
}
}
```
#### Type Filtering and Partial Snapshots
While `bevy_save` aims to make it as easy as possible to save your entire world, some applications also need to be able to save only parts of the world.
[`Builder`] allows you to manually create snapshots like [`DynamicSceneBuilder`]:
```rust,ignore
fn build_snapshot(world: &World, target: Entity, children: Query<&Children>) -> Snapshot {
Snapshot::builder(world)
// Extract all resources
.extract_all_resources()
// Extract all descendants of `target`
// This will include all components not denied by the builder's filter
.extract_entities(children.iter_descendants(target))
// Entities without any components will also be extracted
// You can use `clear_empty` to remove them
.clear_empty()
// Build the `Snapshot`
.build()
}
```
#### Entity hooks
You are also able to add hooks when applying snapshots, similar to `bevy-scene-hook`.
This can be used for many things, like spawning the snapshot as a child of an entity:
```rust,ignore
let snapshot = Snapshot::from_world(world);
snapshot
.applier(world)
// This will be run for every Entity in the snapshot
// It runs after the Entity's Components are loaded
.hook(move |entity, cmds| {
// You can use the hook to add, get, or remove Components
if !entity.contains::<Parent>() {
cmds.set_parent(parent);
}
})
.apply();
```
Hooks may also despawn entities:
```rust,ignore
let snapshot = Snapshot::from_world(world);
snapshot
.applier(world)
.hook(|entity, cmds| {
if entity.contains::<A>() {
cmds.despawn();
}
})
```
#### Entity mapping
As Entity ids are not intended to be used as unique identifiers, `bevy_save` supports mapping Entity ids.
First, you'll need to get a [`ApplierRef`]:
- [`Snapshot::applier()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.Snapshot.html#method.applier)
- [`ApplierRef::new()`](https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.ApplierRef.html#method.new)
The [`ApplierRef`] will then allow you to configure the entity map (and other settings) before applying:
```rust,ignore
let snapshot = Snapshot::from_world(world);
snapshot
.applier(world)
// Your entity map
.entity_map(HashMap::default())
// Despawn all entities matching (With<A>, Without<B>)
.despawn::<(With<A>, Without<B>)>()
.apply();
```
#### MapEntities
`bevy_save` also supports [`MapEntities`](https://docs.rs/bevy/latest/bevy/ecs/entity/trait.MapEntities.html) via reflection to allow you to update entity ids within components and resources.
See [Bevy's Parent Component](https://github.com/bevyengine/bevy/blob/v0.15.3/crates/bevy_hierarchy/src/components/parent.rs) for a simple example.
### Flows
When creating a complex application, snapshot builder and applier functions tend to get complex and unwieldy.
[`Flow`]s are chains of systems used to modularize this process, allowing you to build snapshots and apply them in stages.
They are defined similar to Bevy systems, but they require an input and an output.
Additionally, the introduction of [`Flow`]s allows reflection to become optional - bring your own serialization if you so wish!
```rust,ignore
fn main() {
App::new()
.add_flows(CaptureFlow, (capture_tiles, capture_players, capture_cameras))
.add_flows(ApplyFlow, (apply_tiles, apply_monsters));
}
// User-defined captures make reflection unnecessary
#[derive(Serialize, Deserialize)]
struct MyCapture {
// ... but then you'll need to specify everything you extract
tiles: Vec<(Entity, Tile)>,
players: Vec<(Entity, Transform, Visibility)>,
cameras: Vec<(Entity, Camera)>,
}
// Flow systems have full access to the ECS (even write access)
fn capture_tiles(In(cap): In<MyCapture>, tiles: Query<(Entity, &Tile)>) -> MyCapture {
cap.tiles.extend(query.iter().map(|(e, t)| (e, t.clone())));
cap
}
// Flow systems can be added to flows from anywhere, not just in one location
struct PluginA;
impl Plugin for PluginA {
fn build(&self, app: &mut App) {
app.add_flows(CaptureFlow, another_capture);
}
}
```
#### Pathway
[`Pathway`] is the more flexible version of [`Pipeline`] which allows you to specify your own capture type and use [`Flow`]s.
```rust,ignore
// Pathways look very similar to pipelines, but there are a few key differences
pub struct RONPathway;
impl Pathway for RONPathway {
// The capture type allows you to save anything you want to disk, even without using reflection
type Capture = Snapshot;
type Backend = DefaultDebugBackend;
type Format = RONFormat;
type Key<'a> = &'a str;
fn key(&self) -> Self::Key<'_> {
"examples/saves/flows"
}
// Instead of capturing and applying directly, now these methods just return labels to user-defined flows
// This allows for better dependency injection and reduces code complexity
fn capture(&self, _world: &World) -> impl FlowLabel {
CaptureFlow
}
fn apply(&self, _world: &World) -> impl FlowLabel {
ApplyFlow
}
}
// Flow labels don't encode any behavior by themselves, only point to flows
#[derive(Hash, Debug, PartialEq, Eq, Clone, Copy, FlowLabel)]
pub struct CaptureFlow;
#[derive(Hash, Debug, PartialEq, Eq, Clone, Copy, FlowLabel)]
pub struct ApplyFlow;
```
### Backend
The [`Backend`] is the interface between your application and persistent storage.
Some example backends may include [`FileIO`], sqlite, [`LocalStorage`], or network storage.
```rust,ignore
#[derive(Default, Resource)]
pub struct FileIO;
impl<K: std::fmt::Display + Send> Backend<K> for FileIO {
async fn save<F: Format, T: Serialize>(&self, key: K, value: &T) -> Result<(), Error> {
let path = get_save_file(format!("{key}{}", F::extension()));
let dir = path.parent().expect("Invalid save directory");
create_dir_all(dir).await?;
let mut buf = Vec::new();
F::serialize(&mut buf, value)?;
let mut file = File::create(path).await?;
Ok(file.write_all(&buf).await?)
}
async fn load<F: Format, S: for<'de> DeserializeSeed<'de, Value = T>, T>(
&self,
key: K,
seed: S,
) -> Result<T, Error> {
let path = get_save_file(format!("{key}{}", F::extension()));
let mut file = File::open(path).await?;
let mut buf = Vec::new();
file.read_to_end(&mut buf).await?;
F::deserialize(&*buf, seed)
}
}
```
### Format
[`Format`] is how your application serializes and deserializes your data.
[`Format`]s can either be human-readable like [`JSON`] or binary like [`MessagePack`].
```rust,ignore
pub struct RONFormat;
impl Format for RONFormat {
fn extension() -> &'static str {
".ron"
}
fn serialize<W: Write, T: Serialize>(writer: W, value: &T) -> Result<(), Error> {
let mut ser = ron::Serializer::new(
writer.write_adapter(),
Some(ron::ser::PrettyConfig::default()),
)
.map_err(Error::saving)?;
value.serialize(&mut ser).map_err(Error::saving)
}
fn deserialize<R: Read, S: for<'de> DeserializeSeed<'de, Value = T>, T>(
reader: R,
seed: S,
) -> Result<T, Error> {
ron::options::Options::default()
.from_reader_seed(reader, seed)
.map_err(Error::loading)
}
}
```
### Prefabs
The [`Prefab`] trait allows you to easily spawn entities from a blueprint.
```rust,ignore
#[derive(Component, Default, Reflect)]
#[reflect(Component)]
struct Ball;
#[derive(Reflect)]
struct BallPrefab {
position: Vec3,
}
impl Prefab for BallPrefab {
type Marker = Ball;
fn spawn(self, target: Entity, world: &mut World) {
// Some entities will need initialization from world state, such as mesh assets.
// We can do that here.
let mesh = world.resource_mut::<Assets<Mesh>>().add(Circle::default());
let material = world
.resource_mut::<Assets<ColorMaterial>>()
.add(BALL_COLOR);
world.entity_mut(target).insert((
Mesh2d(mesh),
MeshMaterial2d(material),
Transform::from_translation(self.position)
.with_scale(Vec2::splat(BALL_DIAMETER).extend(1.)),
Ball,
Velocity(INITIAL_BALL_DIRECTION.normalize() * BALL_SPEED),
));
}
fn extract(builder: BuilderRef) -> BuilderRef {
// We don't actually need to save all of those runtime components.
// Only save the translation of the Ball.
builder.extract_prefab(|entity| {
Some(BallPrefab {
position: entity.get::<Transform>()?.translation,
})
})
}
}
```
You are also able to extract resources by type:
```rust,ignore
Snapshot::builder(world)
// Extract the resource by the type name
// In this case, we extract the resource from the `manual` example
.extract_resource::<FancyMap>()
// Build the `Snapshot`
// It will only contain the one resource we extracted
.build()
```
Additionally, explicit type filtering like [`ApplierRef`] is available when building snapshots:
```rust,ignore
Snapshot::builder(world)
// Exclude `Transform` from this `Snapshot`
.deny::<Transform>()
// Extract all matching entities and resources
.extract_all()
// Clear all extracted entities without any components
.clear_empty()
// Build the `Snapshot`
.build()
```
## Stability
`bevy_save` attempts to provide stability guarantees for [`Snapshot`] serialization and deserialization between crate versions on a best-effort basis, enforced with unit tests.
If a breaking change is introduced, **the number after the `+` on the crate version will be incremented** and it will be supported via the `version` method on [`SnapshotDeserializer`].
`bevy_save` relies on serialization to create save files and as such is exposed to internal implementation details for types.
As a result, Bevy or other crate updates may break your save file format.
It should be possible to mitigate this by defining [`ReflectMigrate`] for any offending types.
Changing what entities have what components or how you use your entities or resources in your logic can also result in broken saves.
### Entity
> For all intents and purposes, [`Entity`] should be treated as an opaque identifier. The internal bit representation is liable to change from release to release as are the behaviors or performance characteristics of any of its trait implementations (i.e. `Ord`, `Hash,` etc.). This means that changes in [`Entity`]’s representation, though made readable through various functions on the type, are not considered breaking changes under SemVer.
>
> In particular, directly serializing with `Serialize` and `Deserialize` make zero guarantee of long term wire format compatibility. Changes in behavior will cause serialized [`Entity`] values persisted to long term storage (i.e. disk, databases, etc.) will fail to deserialize upon being updated.
>
> — [Bevy's `Entity` documentation](https://docs.rs/bevy/latest/bevy/ecs/entity/struct.Entity.html#stability-warning)
`bevy_save` serializes and deserializes entities directly. If you need to maintain compatibility across Bevy versions, consider adding a unique identifier [`Component`] to your tracked entities.
## Compatibility
`bevy_save` follows [Semantic Versioning 2.0.0](https://semver.org/), with additional metadata: `MAJOR.MINOR.PATCH+SNAPSHOT`
- **Major**: Breaking API changes and/or [`Snapshot`] format changes
- **Minor**: Backwards-compatible API changes
- **Patch**: Backwards-compatible bug-fixes
- **Snapshot**: [`Snapshot`] version, incremented when the wire format of [`Snapshot`] changes in a way that will break existing applications
### Bevy
| `0.16` | `0.18+3`, `0.19+3`, `1.0+4`<sup> [4](#4)</sup>, `2.0+4` |
| `0.15` | `0.16+3`<sup> [3](#3)</sup>, `0.17+3` |
| `0.14`<sup> [2](#2)</sup> | `0.15+2` |
| `0.13` | `0.14+1` |
| `0.12` | `0.10+1`, `0.11+1`, `0.12+1`, `0.13+1` |
| `0.11` | `0.9+1` |
| `0.10` | `0.4+0`, `0.5+0`, `0.6+1`<sup> [1](#1)</sup>, `0.7+1`, `0.8+1` |
| `0.9` | `0.1`, `0.2+0`<sup> [0](#0)</sup>, `0.3+0` |
#### Snapshot Version
0. <a id="0"></a> `bevy_save` introduced serialization support
1. <a id="1"></a> `bevy_save` introduced a new [`Snapshot`] format
2. <a id="2"></a> `bevy` changed [`Entity`]'s on-disk representation
3. <a id="3"></a> `bevy_save` began using [`FromReflect`] when taking snapshots
4. <a id="4"></a> `bevy_save` introduced a new [`Snapshot`] format, see below
### Migrating
<details>
<summary>0.18+3 -> 0.19+3</summary>
This version introduced [`Pathway`], which is effectively a superset of [`Pipeline`].
- In `World::capture`, `World:apply`, `World::save`, `World::load` methods and similar, add a `&` before your existing pipeline
- Previously provided `Commands` extension traits and associated commands have been removed (since [`Pathway`] operates on references), you'll need to write your own or use events instead
- If you're using `default-features = false`, you'll need to add the `reflect` and `checkpoints` features in order to get parity with the last version
- `SnapshotBuilder` and `SnapshotApplier` have been renamed to [`BuilderRef`] and [`ApplierRef`], respectively.
</details>
<details>
<summary>0.19+3 -> 1.0+4</summary>
This version introduced versioning and migrations.
- Removed the `checkpoints` field from [`Snapshot`], instead saving [`Checkpoints`] as a resource via [`Reflect`].
- `SnapshotVersion::V3` can be used with the `version` method on [`SnapshotDeserializer`] to load a snapshot created in a previous version (since `0.16`) if the snapshot had checkpoints.
- Snapshots created in a previous version without checkpoints should load as expected.
- The fields for all serializers and deserializers have been made private. Use the `new` methods to construct them.
- Non self-describing formats such as `postcard` should now work as expected.
- Deserialization of [`Snapshot`] will fail for this version if `PartialReflect::reflect_clone` is not implemented for all contained types. While this is typically automatically implemented, opaque types must now manually add the attribute `#[reflect(Clone)]` in order for `Snapshot::from_reflect` to succeed.
</details>
<details open>
<summary>1.0+4 -> 2.0+4 (latest)</summary>
This version made some ergonomic changes and fixed a few bugs.
- `Applier` now respects `ReflectMapEntities` for `Component`s.
- `BoxedPartialReflect` is now `DynamicValue`.
- The `CloneReflect` trait has been removed. [`Snapshot`], [`Checkpoints`], and all the wrapper types now implement `Clone`.
- `WorldCheckpointExt::rollback_with` has been removed, use `WorldCheckpointExt::rollback` instead.
- Deserialization of [`Snapshot`] **will no longer fail** if `PartialReflect::reflect_clone` is not implemented for any contained types.
</details>
### Platforms
| Windows | Yes |
| MacOS | Yes |
| Linux | Yes |
| WASM | Yes |
| Android | No |
| iOS | No |
## Feature Flags
| `reflect` | Enables reflection-based snapshots | Yes |
| `checkpoints` | Enables reflection-based checkpoints | Yes |
| `bevy_asset` | Enables `bevy_asset` type registration | Yes |
| `bevy_render` | Enables `bevy_render` type registration | Yes |
| `bevy_sprite` | Enables `bevy_sprite` type registration | Yes |
| `brotli` | Enables `Brotli` compression middleware | No |
## License
`bevy_save` is dual-licensed under MIT and Apache-2.0.
[img_bevy]: https://img.shields.io/badge/Bevy-0.16-blue
[img_version]: https://img.shields.io/crates/v/bevy_save.svg
[img_doc]: https://docs.rs/bevy_save/badge.svg
[img_license]: https://img.shields.io/badge/license-MIT%2FApache-blue.svg
[img_downloads]: https://img.shields.io/crates/d/bevy_save.svg
[img_tracking]: https://img.shields.io/badge/Bevy%20tracking-released%20version-lightblue
[bevy]: https://crates.io/crates/bevy/0.16.1
[crates]: https://crates.io/crates/bevy_save
[doc]: https://docs.rs/bevy_save
[license]: https://github.com/hankjordan/bevy_save#license
[tracking]: https://github.com/bevyengine/bevy/blob/main/docs/plugins_guidelines.md#main-branch-tracking
[`Snapshot`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.Snapshot.html
[`Builder`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.Builder.html
[`BuilderRef`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.BuilderRef.html
[`ApplierRef`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.ApplierRef.html
[`Checkpoints`]: https://docs.rs/bevy_save/latest/bevy_save/checkpoint/struct.Checkpoints.html
[`Pipeline`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Pipeline.html
[`Backend`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Backend.html
[`Format`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Format.html
[`FileIO`]: https://docs.rs/bevy_save/latest/bevy_save/backend/struct.FileIO.html
[`JSON`]: https://docs.rs/bevy_save/latest/bevy_save/format/struct.JSONFormat.html
[`MessagePack`]: https://docs.rs/bevy_save/latest/bevy_save/format/struct.RMPFormat.html
[`Prefab`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Prefab.html
[`Flow`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.Flow.html
[`Pathway`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Pathway.html
[`SnapshotDeserializer`]: https://docs.rs/bevy_save/latest/bevy_save/reflect/struct.SnapshotDeserializer.html
[`Migrate`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/trait.Migrate.html
[`Migrator`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.Migrator.html
[`ReflectMigrate`]: https://docs.rs/bevy_save/latest/bevy_save/prelude/struct.ReflectMigrate.html
[`WORKSPACE`]: https://docs.rs/bevy_save/latest/bevy_save/dir/constant.WORKSPACE.html
[`App`]: https://docs.rs/bevy/latest/bevy/prelude/struct.App.html
[`Component`]: https://docs.rs/bevy/latest/bevy/prelude/trait.Component.html
[`DynamicSceneBuilder`]: https://docs.rs/bevy/latest/bevy/prelude/struct.DynamicSceneBuilder.html
[`Entity`]: https://docs.rs/bevy/latest/bevy/prelude/struct.Entity.html
[`FromReflect`]: https://docs.rs/bevy/latest/bevy/prelude/trait.FromReflect.html
[`Reflect`]: https://docs.rs/bevy/latest/bevy/prelude/trait.Reflect.html
[`ReflectDeserialize`]: https://docs.rs/bevy/latest/bevy/prelude/struct.ReflectDeserialize.html
[`World`]: https://docs.rs/bevy/latest/bevy/prelude/struct.World.html
[`LocalStorage`]: https://docs.rs/web-sys/latest/web_sys/struct.Storage.html