Commit graph

1522 commits

Author SHA1 Message Date
Vic
eaa7dfedea
fix QueryIter::sort_unstable_by (#16565)
# Objective

`QueryIter::sort_unstable_by` is mistakenly using `slice::sort_by`.

## Solution

Use `slice::sort_unstable_by`.
2024-11-30 15:24:35 +00:00
Alice Cecile
75c92fb47b
Clarify inheritance behavior of required components (#16546)
Co-authored by: @BenjaminBrienen

# Objective

Fixes #16494. Closes #16539, which this replaces. Suggestions alone
weren't enough, so now we have a new PR!

---------

Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
2024-11-28 21:09:26 +00:00
Joona Aalto
da68bfe94b
Fix Single doc links (#16493)
# Objective

In the [*Similar parameters* section of
`Query`](https://dev-docs.bevyengine.org/bevy/ecs/prelude/struct.Query.html#similar-parameters),
the doc link for `Single` actually links to `Query::single`, and
`Option<Single>` just links to `Option`. They should both link to
`Single`!

The first link is broken because there is a reference-style link defined
for `single`, but not for `Single`, and rustdoc treats the link as
case-insensitive for some reason.

## Solution

Fix the links!

## Testing

I built the docs locally with `cargo doc` and tested the links.
2024-11-24 18:44:00 +00:00
andriyDev
6741e01dfa
Fix adding a subtree of required components to an existing tree replacing shallower required component constructors (#16441)
# Objective

- Fixes #16406 even more. The previous implementation did not take into
account the depth of the requiree when setting the depth relative to the
required_by component.

## Solution

- Add the depth of the requiree!

## Testing

- Added a test.

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-11-22 00:52:17 +00:00
Illus1on
a54d85bb2d
Correcting misspellings (#16443)
When I browsed the source code I found suspicious misspellings

# Objective

- Correcting misspelling

# Solution
- Change `doesnn't` to `doesn't`
2024-11-21 14:42:56 +00:00
Chris Russell
4362b52a01
Add a note to the on_unimplemented message for QueryData recommending &T and &mut T. (#16449)
# Objective

A new user is likely to try `Query<Component>` instead of
`Query<&Component>`. The error message should guide them to the right
solution.

## Solution

Add a note to the on_unimplemented message for `QueryData` recommending
`&T` and `&mut T`.

The full error message now looks like: 

```
error[E0277]: `A` is not valid to request as data in a `Query`
   --> crates\bevy_ecs\src\query\world_query.rs:260:18
    |
260 | fn system(query: Query<A>) {}
    |                  ^^^^^^^^ invalid `Query` data
    |
    = help: the trait `fetch::QueryData` is not implemented for `A`
    = note: if `A` is a component type, try using `&A` or `&mut A`
    = help: the following other types implement trait `fetch::QueryData`:
              &'__w mut T
              &Archetype
              &T
              ()
              (F,)
              (F0, F1)
              (F0, F1, F2)
              (F0, F1, F2, F3)
            and 41 others
note: required by a bound in `system::query::Query`
   --> crates\bevy_ecs\src\system\query.rs:362:37
    |
362 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> {
    |                                     ^^^^^^^^^ required by this bound in `Query`
```
2024-11-21 03:52:10 +00:00
Carter Anderson
deda3f2522
Fix detailed_trace! (#16452)
Alternative to #16450 

# Objective

detailed_trace! in its current form does not work  (and breaks CI)

## Solution

Fix detailed_trace by checking for the feature properly, adding it to
the correct crates, and removing it from the incorrect crates
2024-11-20 22:01:33 +00:00
andriyDev
4a6b686832
Fix runtime required components not registering correctly (#16436)
# Objective

- Fixes #16406 
- Fixes an issue where registering a "deeper" required component, then a
"shallower" required component, would result in the wrong required
constructor being used for the root component.

## Solution

- Make `register_required_components` add any "parent" of a component as
`required_by` to the new "child".
- Assign the depth of the `requiree` plus 1 as the depth of a new
runtime required component.

## Testing

- Added two new tests.
2024-11-19 16:31:00 +00:00
Joona Aalto
ded5ce27ae
Fix bubbling of runtime requirements for #[require(...)] attribute (#16410)
# Objective

Fixes #16406.

Currently, the `#[require(...)]` attribute internally registers
component requirements using `register_required_components_manual`. This
is done recursively in a way where every requirement in the "inheritance
tree" is added into a flat `RequiredComponents` hash map with component
constructors and inheritance depths stored.

However, this does not consider runtime requirements: if a plugins has
already registered `C` as required by `B`, and a component `A` requires
`B` through the macro attribute, spawning an entity with `A` won't add
`C`. The `required_by` hash set for `C` doesn't have `A`, and the
`RequiredComponents` of `A` don't have `C`.

Intuitively, I would've thought that the macro attribute's requirements
were always added *before* runtime requirements, and in that case I
believe this shouldn't have been an issue. But the macro requirements
are based on `Component::register_required_components`, which in a lot
of cases (I think) is only called *after* the first time a bundle with
the component is inserted. So if a runtime requirement is defined
*before* this (as is often the case, during `Plugin::build`), the macro
may not take it into account.

## Solution

Register requirements inherited from the `required` component in
`register_required_components_manual_unchecked`.

## Testing

I added a test, essentially the same as in #16406, and it now passes. I
also ran some of the tests in #16409, and they seem to work as expected.
All the existing tests for required components pass.
2024-11-17 13:51:39 +00:00
Christian Hughes
d3e9ecbb8c
Add missing exports in bevy_ecs (#16415)
# Objective

Seemed to have missed the export of `DynamicComponentFetch` from #15593.
`TryFromFilteredError` which is returned by `impl
TryFrom<FiliteredEntityMut/Ref> for EntityRef/Mut` also seemed to have
been missing.

## Solution

Export both of them.
2024-11-17 09:47:33 +00:00
Benjamin Brienen
8dfd076982
Fix MSRVs for standalone crates (#16333)
# Objective

MSRV in the standalone crates should be accurate

## Solution

Determine the msrv of each crate and set it

## Testing

Adding better msrv checks to the CI is a next-step.
2024-11-17 09:38:13 +00:00
Volodymyr Enhelhardt
db1915a1f0
Use the fully qualified name for Component in the require attribute (#16378)
# Objective

- Describe the objective or issue this PR addresses.
Use the fully qualified name for `Component` in the `require` attribute

- If you're fixing a specific issue, say "Fixes #X".
Fixes #16377

## Solution

- Describe the solution used to achieve the objective above.
Use the fully qualified name for `Component` in the `require` attribute,
i.e.,`<#ident as #bevy_ecs_path::component::Component>`

## Testing

- Did you test these changes? If so, how?
`cargo run -p ci -- lints`
`cargo run -p ci -- compile`
`cargo run -p ci -- test`
- Are there any parts that need more testing?
no
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
try to compile
```rust
#[derive(::bevy::ecs::component::Component, Default)]
pub struct A;

#[derive(::bevy::ecs::component::Component)]
#[require(A)]
pub struct B;
```
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
Mac only
---


</details>

## Migration Guide

> This section is optional. If there are no breaking changes, you can
delete this section.

- If this PR is a breaking change (relative to the last release of
Bevy), describe how a user might need to migrate their code to support
these changes
- Simply adding new functionality is not a breaking change.
- Fixing behavior that was definitely a bug, rather than a questionable
design choice is not a breaking change.

Co-authored-by: Volodymyr Enhelhardt <volodymyr.enhelhardt@ambr.net>
2024-11-13 20:37:50 +00:00
Rob Grindeland
a8c610a52d
Add unregister_system command (#16340)
# Objective

Fixes #16266 

## Solution

Added an `UnregisterSystem` command struct and
`Commands::unregister_system`. Also renamed `World::remove_system` and
`World::remove_system_cached` to `World::unregister_*`

## Testing

It's a fairly simple change, but I tested locally to ensure it actually
works.

---------

Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com>
2024-11-12 22:49:29 +00:00
François Mockers
4225848b0a
undeprecate component_reads_and_writes (#16357)
# Objective

- Does not correct #16339 but takes it out of the 0.15 milestone

## Solution

- Make it future us problem instead of solving it now
2024-11-11 23:28:16 +00:00
Sou1gh0st
b83c0e106e
Add EntityMut::get_mut_by_id_unchecked (#16210)
# Objective

- Fixes: #15603 

## Solution

- Add an unsafe `get_mut_by_id_unchecked` to `EntityMut` that borrows
&self instead of &mut self, thereby allowing access to multiple
components simultaneously.

## Testing

- a unit test function `get_mut_by_id_unchecked` was added.

---------

Co-authored-by: Mike <mike.hsu@gmail.com>
2024-11-11 18:46:47 +00:00
Zachary Harrold
d143da338a
Fixed issue with derive_more Display Implementations (#16298)
# Objective

- Fixed issue where `thiserror` `#[error(...)]` attributes were
improperly converted to `derive_more` `#[display(...)]` equivalents in
certain cases with a tuple struct/enum variant.

## Solution

- Used `re/#\[display\(.*\{[0-9]+\}.*\)\]/` to find occurences of using
`{0}` where `{_0}` was intended (checked for other field indexes too)and
updated accordingly.

## Testing

- `cargo check`
- CI

## Notes

This was discovered by @dtolnay in [this
comment](https://github.com/bevyengine/bevy/pull/15772#discussion_r1833730555).
2024-11-08 20:29:52 +00:00
Hennadii Chernyshchyk
e53aaddf96
Make ComponentTicks field public (#16269)
# Objective

After #12929 we no longer have methods to get component or ticks for
previously obtained table column.
It's possible to use a lower level API by indexing the slice, but then
it won't be possible to construct `ComponentTicks`.

## Solution

Make `ComponentTicks` fields public. They don't hold any invariants and
you can't get a mutable reference to the struct in Bevy.

I also removed the getters since they are no longer needed.

## Testing

- I tested the compilation

---

## Migration Guide

- Instead of using `ComponentTicks::last_changed_tick` and
`ComponentTicks::added_tick` methods, access fields directly.
2024-11-06 22:21:04 +00:00
Chris Russell
a967c75e92
Enable EntityRef tests that now pass. (#16263)
# Objective

Re-enable some tests in `entity_ref.rs` that are marked as `#[ignore]`,
but that pass after #14561.

## Solution

Remove `#[ignore]` from those tests.
2024-11-06 16:10:55 +00:00
Derick M
8d24efe60c
Remove unused debug identifiers for ComponentHooks methods (#16228)
# Objective

- Cleans up unused debug identifiers for `ComponentHooks` methods:
`on_add`, `on_insert`, `on_replace`, and `on_remove`
 
## Solution

- Simplify the expect messages by removing the unused `{:?}`

## Testing

- Currently untested


[Context](https://discord.com/channels/691052431525675048/749335865876021248/1302988180592525362)
2024-11-04 15:41:07 +00:00
urben1680
1e47604506
Adding ScheduleGraph::contains_set (#16206)
# Objective

The schedule graph can easily confirm whether a set is contained or not.

This helps me in my personal project where I write an extension trait
for `Schedule` and I want to configure a specific set in its methods.
The set in question has a run condition though and I don't want to add
that condition to the same schedule as many times as the trait methods
are called. Since the non-pub set is unknown to the schedule until then,
a `contains_set` is sufficient.

It is probably trivial to add a method that returns an `Option<NodeId>`
as well but as I personally don't need it I did not add that. If it is
desired I can do so here though. It might be unneeded to have a
`contains_set` then because one could check `is_some` on the returned id
in that case.

An argument against that is that future changes may be easier if only a
`contains_set` needs to be ported.

## Solution

Added `ScheduleGraph::contains_set`.

## Testing

I put the below showcase code into a temporary unit test and it worked.
If wanted I add it as a test too but I did not see that other more
somewhat complicated methods have tests

---

## Showcase

```rs
#[derive(ScheduleLabel, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct MySchedule;

#[derive(SystemSet, Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
struct MySet;

let mut schedule = Schedule::new(MySchedule);
assert_eq!(schedule.graph().contains_set(MySet), false);
schedule.configure_sets(MySet);
assert_eq!(schedule.graph().contains_set(MySet), true);
```
2024-11-03 16:16:24 +00:00
MiniaczQ
5edc23db41
Fix fallible param notes (#16218)
I noticed one of the reflinks doesn't work correctly
2024-11-03 16:14:26 +00:00
Benjamin Brienen
f005a96dd4
ReflectBundle::remove improvement (#16139)
# Objective

Fixes #15676

## Solution

`remove` returns the removed item

Add `take`

## Testing

None yet

## Migration Guide

If you don't need the returned value from `remove`, discard it.
2024-10-28 22:29:05 +00:00
Tau Gärtli
a644ac73f7
More #[doc(fake_variadic)] goodness (#16108)
This PR adds `#[doc(fake_variadic)]` to that were previously not
supported by rustdoc.

Thanks to an [upstream
contribution](https://github.com/rust-lang/rust/pull/132115) by yours
truly, `#[doc(fake_variadic)]` is now supported on impls such as `impl
QueryData for AnyOf<(T, ...)>` 🎉
Requires the latest nightly compiler (2024-10-25) which is already
available on [docs.rs](https://docs.rs/about/builds).


![image](https://github.com/user-attachments/assets/68589c7e-f68f-44fb-9a7b-09d24ccf19c9)

![image](https://github.com/user-attachments/assets/f09d20d6-d89b-471b-9a81-4a72c8968178)

This means that the impl sections for `QueryData` and `QueryFilter` are
now nice and tidy 

---

I also added `fake_variadic` to some impls that use
`all_tuples_with_size`, however I'm not entirely happy because the docs
are slightly misleading now:


![image](https://github.com/user-attachments/assets/fac93d08-dc02-430f-9f34-c97456256c56)

Note that the docs say `IntoBindGroupLayoutEntryBuilderArray<1>` instead
of
`IntoBindGroupLayoutEntryBuilderArray<N>`.
2024-10-27 19:01:50 +00:00
Rob Parrett
30d84519a2
Use en-us locale for typos (#16037)
# Objective

Bevy seems to want to standardize on "American English" spellings. Not
sure if this is laid out anywhere in writing, but see also #15947.

While perusing the docs for `typos`, I noticed that it has a `locale`
config option and tried it out.

## Solution

Switch to `en-us` locale in the `typos` config and run `typos -w`

## Migration Guide

The following methods or fields have been renamed from `*dependants*` to
`*dependents*`.

- `ProcessorAssetInfo::dependants`
- `ProcessorAssetInfos::add_dependant`
- `ProcessorAssetInfos::non_existent_dependants`
- `AssetInfo::dependants_waiting_on_load`
- `AssetInfo::dependants_waiting_on_recursive_dep_load`
- `AssetInfos::loader_dependants`
- `AssetInfos::remove_dependants_and_labels`
2024-10-20 18:55:17 +00:00
SpecificProtagonist
3eec0f0a77
QueryEntityError: Use short name for components (#16032)
Use the new `disqualified` crate in `QueryEntityError` to make the error
message more readable.

---

## Showcase

Old:
QueryDoesNotMatch(0v1 with components my_game::main::foo::A,
my_game::main::foo::B, bevy_pbr::light::point_light::PointLight,
bevy_render::primitives::CubemapFrusta,
bevy_pbr::bundle::CubemapVisibleEntities,
bevy_transform::components::transform::Transform,
bevy_transform::components::global_transform::GlobalTransform,
bevy_render::view::visibility::Visibility,
bevy_render::view::visibility::InheritedVisibility,
bevy_render::view::visibility::ViewVisibility,
bevy_render::sync_world::SyncToRenderWorld)

New:
QueryDoesNotMatch(0v1 with components A, B, PointLight, CubemapFrusta,
CubemapVisibleEntities, Transform, GlobalTransform, Visibility,
InheritedVisibility, ViewVisibility, SyncToRenderWorld)

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-10-20 17:56:43 +00:00
Peter Hayman
75096fbf97
fix: add reflect to SceneInstanceReady and other observers/events (#16018)
# Objective

Built-in observers & events should be `Reflect` so that components that
interact with them can be serialized in scenes. This is a similar pr to
#14259.
2024-10-20 13:51:41 +00:00
Rob Parrett
da5d2fccf5
Fix some duplicate words in docs/comments (#15980)
# Objective

Stumbled upon one of these, and set off in search of more, armed with my
trusty `\b(\w+)\s+\1\b`.

## Solution

Remove ~one~ one of them.
2024-10-20 01:03:27 +00:00
Carter Anderson
015f2c69ca
Merge Style properties into Node. Use ComputedNode for computed properties. (#15975)
# Objective

Continue improving the user experience of our UI Node API in the
direction specified by [Bevy's Next Generation Scene / UI
System](https://github.com/bevyengine/bevy/discussions/14437)

## Solution

As specified in the document above, merge `Style` fields into `Node`,
and move "computed Node fields" into `ComputedNode` (I chose this name
over something like `ComputedNodeLayout` because it currently contains
more than just layout info. If we want to break this up / rename these
concepts, lets do that in a separate PR). `Style` has been removed.

This accomplishes a number of goals:

## Ergonomics wins

Specifying both `Node` and `Style` is now no longer required for
non-default styles

Before:
```rust
commands.spawn((
    Node::default(),
    Style {
        width:  Val::Px(100.),
        ..default()
    },
));
```

After:

```rust
commands.spawn(Node {
    width:  Val::Px(100.),
    ..default()
});
```

## Conceptual clarity

`Style` was never a comprehensive "style sheet". It only defined "core"
style properties that all `Nodes` shared. Any "styled property" that
couldn't fit that mold had to be in a separate component. A "real" style
system would style properties _across_ components (`Node`, `Button`,
etc). We have plans to build a true style system (see the doc linked
above).

By moving the `Style` fields to `Node`, we fully embrace `Node` as the
driving concept and remove the "style system" confusion.

## Next Steps

* Consider identifying and splitting out "style properties that aren't
core to Node". This should not happen for Bevy 0.15.

---

## Migration Guide

Move any fields set on `Style` into `Node` and replace all `Style`
component usage with `Node`.

Before:
```rust
commands.spawn((
    Node::default(),
    Style {
        width:  Val::Px(100.),
        ..default()
    },
));
```

After:

```rust
commands.spawn(Node {
    width:  Val::Px(100.),
    ..default()
});
```

For any usage of the "computed node properties" that used to live on
`Node`, use `ComputedNode` instead:

Before:
```rust
fn system(nodes: Query<&Node>) {
    for node in &nodes {
        let computed_size = node.size();
    }
}
```

After:
```rust
fn system(computed_nodes: Query<&ComputedNode>) {
    for computed_node in &computed_nodes {
        let computed_size = computed_node.size();
    }
}
```
2024-10-18 22:25:33 +00:00
Christian Hughes
345f935b1a
Add Trigger::components, which lists the component targets that were triggered (#15811)
# Objective

- Closes #14774 

## Solution

Added:

```rust
impl<'w, E, B: Bundle> Trigger<'w, E, B> {
    pub fn components(&self) -> &[ComponentId];
}
```

I went with storing it in the trigger as a `SmallVec<[Component; 1]>`
because a singular target component will be the most common case, and it
remains the same size as `Vec<ComponentId>`.

## Testing

Added a test.
2024-10-15 02:17:03 +00:00
Clar Fon
e79bc7811d
Fix *most* clippy lints (#15906)
# Objective

Another clippy-lint fix: the goal is so that `ci lints` actually
displays the problems that a contributor caused, and not a bunch of
existing stuff in the repo. (when run on nightly)

## Solution

This fixes all but the `clippy::needless_lifetimes` lint, which will
result in substantially more fixes and be in other PR(s). I also
explicitly allow `non_local_definitions` since it is [not working
correctly, but will be
fixed](https://github.com/rust-lang/rust/issues/131643).

A few things were manually fixed: for example, some places had an
explicitly defined `div_ceil` function that was used, which is no longer
needed since this function is stable on unsigned integers. Also, empty
lines in doc comments were handled individually.

## Testing

I ran `cargo clippy --workspace --all-targets --all-features --fix
--allow-staged` with the `clippy::needless_lifetimes` lint marked as
`allow` in `Cargo.toml` to avoid fixing that too. It now passes with all
but the listed lint.
2024-10-14 20:52:35 +00:00
Alice Cecile
a7e9330af9
Implement WorldQuery for MainWorld and RenderWorld components (#15745)
# Objective

#15320 is a particularly painful breaking change, and the new
`RenderEntity` in particular is very noisy, with a lot of `let entity =
entity.id()` spam.

## Solution

Implement `WorldQuery`, `QueryData` and `ReadOnlyQueryData` for
`RenderEntity` and `WorldEntity`.

These work the same as the `Entity` impls from a user-facing
perspective: they simply return an owned (copied) `Entity` identifier.
This dramatically reduces noise and eases migration.

Under the hood, these impls defer to the implementations for `&T` for
everything other than the "call .id() for the user" bit, as they involve
read-only access to component data. Doing it this way (as opposed to
implementing a custom fetch, as tried in the first commit) dramatically
reduces the maintenance risk of complex unsafe code outside of
`bevy_ecs`.

To make this easier (and encourage users to do this themselves!), I've
made `ReadFetch` and `WriteFetch` slightly more public: they're no
longer `doc(hidden)`. This is a good change, since trying to vendor the
logic is much worse than just deferring to the existing tested impls.

## Testing

I've run a handful of rendering examples (breakout, alien_cake_addict,
auto_exposure, fog_volumes, box_shadow) and nothing broke.

## Follow-up

We should lint for the uses of `&RenderEntity` and `&MainEntity` in
queries: this is just less nice for no reason.

---------

Co-authored-by: Trashtalk217 <trashtalk217@gmail.com>
2024-10-13 20:58:46 +00:00
Pablo Reinhardt
d96a9d15f6
Migrate from Query::single and friends to Single (#15872)
# Objective

- closes #15866

## Solution

- Simply migrate where possible.

## Testing

- Expect that CI will do most of the work. Examples is another way of
testing this, as most of the work is in that area.
---

## Notes
For now, this PR doesn't migrate `QueryState::single` and friends as for
now, this look like another issue. So for example, QueryBuilders that
used single or `World::query` that used single wasn't migrated. If there
is a easy way to migrate those, please let me know.

Most of the uses of `Query::single` were removed, the only other uses
that I found was related to tests of said methods, so will probably be
removed when we remove `Query::single`.
2024-10-13 20:32:06 +00:00
JaySpruce
3d6b24880e
Add insert_batch and variations (#15702)
# Objective

`insert_or_spawn_batch` exists, but a version for just inserting doesn't
- Closes #2693 
- Closes #8384 
- Adopts/supersedes #8600 

## Solution

Add `insert_batch`, along with the most common `insert` variations:
- `World::insert_batch`
- `World::insert_batch_if_new`
- `World::try_insert_batch`
- `World::try_insert_batch_if_new`
- `Commands::insert_batch`
- `Commands::insert_batch_if_new`
- `Commands::try_insert_batch`
- `Commands::try_insert_batch_if_new`

## Testing

Added tests, and added a benchmark for `insert_batch`.
Performance is slightly better than `insert_or_spawn_batch` when only
inserting:


![Code_HPnUN0QeWe](https://github.com/user-attachments/assets/53091e4f-6518-43f4-a63f-ae57d5470c66)

<details>
<summary>old benchmark</summary>

This was before reworking it to remove the `UnsafeWorldCell`:


![Code_QhXJb8sjlJ](https://github.com/user-attachments/assets/1061e2a7-a521-48e1-a799-1b6b8d1c0b93)
</details>

---

## Showcase

Usage is the same as `insert_or_spawn_batch`:
```
use bevy_ecs::{entity::Entity, world::World, component::Component};
#[derive(Component)]
struct A(&'static str);
#[derive(Component, PartialEq, Debug)]
struct B(f32);

let mut world = World::new();
let entity_a = world.spawn_empty().id();
let entity_b = world.spawn_empty().id();
world.insert_batch([
    (entity_a, (A("a"), B(0.0))),
    (entity_b, (A("b"), B(1.0))),
]);

assert_eq!(world.get::<B>(entity_a), Some(&B(0.0)));

```
2024-10-13 18:14:16 +00:00
Andrew
6a39c33d49
Use oslog for ios (#13364)
# Objective

On mobile devices, it's best to use the OS's native logging due to the
difficulty of accessing the console. This is already done for Android.

This is an updated version of
https://github.com/bevyengine/bevy/pull/4462.

## Solution

This PR uses Absolucy's
[tracing-oslog](https://github.com/Absolucy/tracing-oslog) ([ZLib
license](https://github.com/Absolucy/tracing-oslog/blob/main/LICENSE.md))
for iOS in order to use Apple's `os_log`.

## Testing

I ran `examples/mobile` with the logging from `examples/app/logs.rs` on
an iOS device, I then checked the logs could be filtered in the MacOS
Console.app.

## Changelog

 - Change bevy_log to use Apple's os_log on iOS.

## Questions for Reviewers
It's worth noting that the dependency this adds hasn't had bug fixes
released in a few years, so we may want to consider one or more of:
 1. a feature flag to opt-in, and it would also allow `os_log` on MacOS
 2. merge as-is and have some (minor?) upstream bugs
 3. hold off on this PR until a suitable alternative dependency arises
 4. maintain our own implementation

## Future work

In a follow-up PR it might be good to make the `subsystem` field have a
better default value, like [this
one](https://github.com/bevyengine/bevy/blob/main/examples/mobile/bevy_mobile_example.xcodeproj/project.pbxproj#L363).
That value can be retrieved programmatically if we bind another system
API (For posterity in Swift this is `Bundle.main.bundleIdentifier`, but
the C/ObjC equivalent is likely easier to bind). This would almost
always be the correct value, while the current default is unlikely to
ever be correct.

---------

Co-authored-by: Dusty DeWeese <dustin.deweese@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2024-10-11 08:58:14 +00:00
Gino Valente
da4e7769ad
bevy_ecs: Special-case Entity::PLACEHOLDER formatting (#15839)
# Objective

Oftentimes, users will store an entity on a component or resource. To
make this component/resource `Default`-able, they might initialize it
with `Entity::PLACEHOLDER`. This is sometimes done to avoid the need for
an `Option<Entity>`, especially if it complicates other logic.

For example, it's used in this `Selection` resource to denote "no
selection":

```rust
#[derive(Resource, Debug)]
struct Selection(Entity);

impl Default for Selection {
    fn default() -> Self {
        Self(Entity::PLACEHOLDER)
    }
}
```

The problem is that if we try to `Debug` the current `Selection`, we get
back: `4294967295v1#8589934591`. It's not immediately obvious whether or
not the entity is an actual entity or the placeholder.

Now while it doesn't take long to realize that this is in fact just the
value of `Entity::PLACEHOLDER`, it would be a lot clearer if this was
made explicit, especially for these particular use cases.

## Solution

This PR makes the `Debug` and `Display` impls for `Entity` return
`PLACEHOLDER` for the `Entity::PLACEHOLDER` constant.

~~Feel free to bikeshed the actual value returned here. I think
`PLACEHOLDER` on its own could work too.~~ Swapped to `PLACEHOLDER` from
`Entity::PLACEHOLDER`.

## Testing

You can test locally by running:

```
cargo test --package bevy_ecs
```

---

## Migration Guide

The `Debug` and `Display` impls for `Entity` now return `PLACEHOLDER`
for the `Entity::PLACEHOLDER` constant. If you had any code relying on
these values, you may need to account for this change.
2024-10-11 03:12:01 +00:00
Christian Hughes
b4071ca370
Add World::get_resource_or_init as an alternative to World::get_resource_or_insert_with (#15758)
# Objective

If a `Resource` implements `FromWorld` or `Default`, it's nicer to be
able to write:

```rust
let foo = world.get_resource_or_init::<Foo>();
```

Rather than:

```rust
let foo = world.get_resource_or_insert_with(Foo::default);
```

The latter is also not possible if a type implements `FromWorld` only,
and not `Default`.

## Solution

Added:

```rust
impl World {
    pub fn get_resource_or_init<R: Resource + FromWorld>(&mut self) -> Mut<'_, R>;
}
```

Turns out all current in-engine uses of `get_resource_or_insert_with`
are exactly the above, so they've also been replaced.

## Testing

- Added a doc-test.
- Also added a doc-test for `World::get_resource_or_insert_with`.
2024-10-09 20:56:26 +00:00
UkoeHB
c2c19e5ae4
Text rework (#15591)
**Ready for review. Examples migration progress: 100%.**

# Objective

- Implement https://github.com/bevyengine/bevy/discussions/15014

## Solution

This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.

Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.

## Testing

- [x] Text examples all work.

---

## Showcase

TODO: showcase-worthy

## Migration Guide

TODO: very breaking

### Accessing text spans by index

Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.

Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
    let text = query.single_mut();
    text.sections[1].value = format_time(time.elapsed());
}
```

After:
```rust
fn refresh_text(
    query: Query<Entity, With<TimeText>>,
    mut writer: UiTextWriter,
    time: Res<Time>
) {
    let entity = query.single();
    *writer.text(entity, 1) = format_time(time.elapsed());
}
```

### Iterating text spans

Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.

---------

Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-09 18:35:36 +00:00
Emerson Coskey
7d40e3ec87
Migrate bevy_sprite to required components (#15489)
# Objective

Continue migration of bevy APIs to required components, following
guidance of https://hackmd.io/@bevy/required_components/

## Solution

- Make `Sprite` require `Transform` and `Visibility` and
`SyncToRenderWorld`
- move image and texture atlas handles into `Sprite`
- deprecate `SpriteBundle`
- remove engine uses of `SpriteBundle`

## Testing

ran cargo tests on bevy_sprite and tested several sprite examples.

---

## Migration Guide

Replace all uses of `SpriteBundle` with `Sprite`. There are several new
convenience constructors: `Sprite::from_image`,
`Sprite::from_atlas_image`, `Sprite::from_color`.

WARNING: use of `Handle<Image>` and `TextureAtlas` as components on
sprite entities will NO LONGER WORK. Use the fields on `Sprite` instead.
I would have removed the `Component` impls from `TextureAtlas` and
`Handle<Image>` except it is still used within ui. We should fix this
moving forward with the migration.
2024-10-09 16:17:26 +00:00
Christian Hughes
219b5930f1
Rename App/World::observe to add_observer, EntityWorldMut::observe_entity to observe. (#15754)
# Objective

- Closes #15752

Calling the functions `App::observe` and `World::observe` doesn't make
sense because you're not "observing" the `App` or `World`, you're adding
an observer that listens for an event that occurs *within* the `World`.
We should rename them to better fit this.

## Solution

Renames:
- `App::observe` -> `App::add_observer`
- `World::observe` -> `World::add_observer`
- `Commands::observe` -> `Commands::add_observer`
- `EntityWorldMut::observe_entity` -> `EntityWorldMut::observe`

(Note this isn't a breaking change as the original rename was introduced
earlier this cycle.)

## Testing

Reusing current tests.
2024-10-09 15:39:29 +00:00
Zachary Harrold
0a61f04d9b
Remove thiserror from bevy_ecs (#15774)
# Objective

- Contributes to #15460

## Solution

- Removed `thiserror` from `bevy_ecs`
2024-10-09 14:20:58 +00:00
Gino Valente
8039f34b0d
bevy_ecs: Replace panics in QueryData derive compile errors (#15691)
# Objective

The current `QueryData` derive panics when it encounters an error.
Additionally, it doesn't provide the clearest error message:

```rust
#[derive(QueryData)]
#[query_data(mut)]
struct Foo {
    // ...
}
```

```
error: proc-macro derive panicked
  --> src/foo.rs:16:10
   |
16 | #[derive(QueryData)]
   |          ^^^^^^^^^
   |
   = help: message: Invalid `query_data` attribute format
```

## Solution

Updated the derive logic to not panic and gave a bit more detail in the
error message.

This is makes the error message just a bit clearer and maintains the
correct span:

```
error: invalid attribute, expected `mutable` or `derive`
  --> src/foo.rs:17:14
   |
17 | #[query_data(mut)]
   |              ^^^
```

## Testing

You can test locally by running the following in
`crates/bevy_ecs/compile_fail`:

```
cargo test --target-dir ../../../target
```
2024-10-07 16:30:34 +00:00
Trashtalk217
d1bd46d45e
Deprecate get_or_spawn (#15652)
# Objective

After merging retained rendering world #15320, we now have a good way of
creating a link between worlds (*HIYAA intensifies*). This means that
`get_or_spawn` is no longer necessary for that function. Entity should
be opaque as the warning above `get_or_spawn` says. This is also part of
#15459.

I'm deprecating `get_or_spawn_batch` in a different PR in order to keep
the PR small in size.

## Solution

Deprecate `get_or_spawn` and replace it with `get_entity` in most
contexts. If it's possible to query `&RenderEntity`, then the entity is
synced and `render_entity.id()` is initialized in the render world.

## Migration Guide

If you are given an `Entity` and you want to do something with it, use
`Commands.entity(...)` or `World.entity(...)`. If instead you want to
spawn something use `Commands.spawn(...)` or `World.spawn(...)`. If you
are not sure if an entity exists, you can always use `get_entity` and
match on the `Option<...>` that is returned.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-10-07 16:08:22 +00:00
Christian Hughes
584d14808a
Allow World::entity family of functions to take multiple entities and get multiple references back (#15614)
# Objective

Following the pattern established in #15593, we can reduce the API
surface of `World` by providing a single function to grab both a
singular entity reference, or multiple entity references.

## Solution

The following functions can now also take multiple entity IDs and will
return multiple entity references back:
- `World::entity`
- `World::get_entity`
- `World::entity_mut`
- `World::get_entity_mut`
- `DeferredWorld::entity_mut`
- `DeferredWorld::get_entity_mut`

If you pass in X, you receive Y:
- give a single `Entity`, receive a single `EntityRef`/`EntityWorldMut`
(matches current behavior)
- give a `[Entity; N]`/`&[Entity; N]` (array), receive an equally-sized
`[EntityRef; N]`/`[EntityMut; N]`
- give a `&[Entity]` (slice), receive a
`Vec<EntityRef>`/`Vec<EntityMut>`
- give a `&EntityHashSet`, receive a
`EntityHashMap<EntityRef>`/`EntityHashMap<EntityMut>`

Note that `EntityWorldMut` is only returned in the single-entity case,
because having multiple at the same time would lead to UB. Also,
`DeferredWorld` receives an `EntityMut` in the single-entity case
because it does not allow structural access.

## Testing

- Added doc-tests on `World::entity`, `World::entity_mut`, and
`DeferredWorld::entity_mut`
- Added tests for aliased mutability and entity existence

---

## Showcase

<details>
  <summary>Click to view showcase</summary>

The APIs for fetching `EntityRef`s and `EntityMut`s from the `World`
have been unified.

```rust
// This code will be referred to by subsequent code blocks.
let world = World::new();
let e1 = world.spawn_empty().id();
let e2 = world.spawn_empty().id();
let e3 = world.spawn_empty().id();
```

Querying for a single entity remains mostly the same:

```rust
// 0.14
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Option<EntityRef> = world.get_entity(e1);
let emut: Option<EntityWorldMut> = world.get_entity_mut(e1);

// 0.15
let eref: EntityRef = world.entity(e1);
let emut: EntityWorldMut = world.entity_mut(e1);
let eref: Result<EntityRef, Entity> = world.get_entity(e1);
let emut: Result<EntityWorldMut, Entity> = world.get_entity_mut(e1);
```

Querying for multiple entities with an array has changed:

```rust
// 0.14
let erefs: [EntityRef; 2] = world.many_entities([e1, e2]);
let emuts: [EntityMut; 2] = world.many_entities_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_many_entities([e1, e2]);
let emuts: Result<[EntityMut; 2], QueryEntityError> = world.get_many_entities_mut([e1, e2]);

// 0.15
let erefs: [EntityRef; 2] = world.entity([e1, e2]);
let emuts: [EntityMut; 2] = world.entity_mut([e1, e2]);
let erefs: Result<[EntityRef; 2], Entity> = world.get_entity([e1, e2]);
let emuts: Result<[EntityMut; 2], EntityFetchError> = world.get_entity_mut([e1, e2]);
```

Querying for multiple entities with a slice has changed:

```rust
let ids = vec![e1, e2, e3]);

// 0.14
let erefs: Result<Vec<EntityRef>, Entity> = world.get_many_entities_dynamic(&ids[..]);
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_dynamic_mut(&ids[..]);

// 0.15
let erefs: Result<Vec<EntityRef>, Entity> = world.get_entity(&ids[..]);
let emuts: Result<Vec<EntityMut>, EntityFetchError> = world.get_entity_mut(&ids[..]);
let erefs: Vec<EntityRef> = world.entity(&ids[..]); // Newly possible!
let emuts: Vec<EntityMut> = world.entity_mut(&ids[..]); // Newly possible!
```

Querying for multiple entities with an `EntityHashSet` has changed:

```rust
let set = EntityHashSet::from_iter([e1, e2, e3]);

// 0.14
let emuts: Result<Vec<EntityMut>, QueryEntityError> = world.get_many_entities_from_set_mut(&set);

// 0.15
let emuts: Result<EntityHashMap<EntityMut>, EntityFetchError> = world.get_entity_mut(&set);
let erefs: Result<EntityHashMap<EntityRef>, EntityFetchError> = world.get_entity(&set); // Newly possible!
let emuts: EntityHashMap<EntityMut> = world.entity_mut(&set); // Newly possible!
let erefs: EntityHashMap<EntityRef> = world.entity(&set); // Newly possible!
```

</details>

## Migration Guide

- `World::get_entity` now returns `Result<_, Entity>` instead of
`Option<_>`.
- Use `world.get_entity(..).ok()` to return to the previous behavior.
- `World::get_entity_mut` and `DeferredWorld::get_entity_mut` now return
`Result<_, EntityFetchError>` instead of `Option<_>`.
- Use `world.get_entity_mut(..).ok()` to return to the previous
behavior.
- Type inference for `World::entity`, `World::entity_mut`,
`World::get_entity`, `World::get_entity_mut`,
`DeferredWorld::entity_mut`, and `DeferredWorld::get_entity_mut` has
changed, and might now require the input argument's type to be
explicitly written when inside closures.
- The following functions have been deprecated, and should be replaced
as such:
    - `World::many_entities` -> `World::entity::<[Entity; N]>`
    - `World::many_entities_mut` -> `World::entity_mut::<[Entity; N]>`
    - `World::get_many_entities` -> `World::get_entity::<[Entity; N]>`
- `World::get_many_entities_dynamic` -> `World::get_entity::<&[Entity]>`
- `World::get_many_entities_mut` -> `World::get_entity_mut::<[Entity;
N]>`
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_dynamic_mut` ->
`World::get_entity_mut::<&[Entity]>1
- The equivalent return type has changed from `Result<_,
QueryEntityError>` to `Result<_, EntityFetchError>`
- `World::get_many_entities_from_set_mut` ->
`World::get_entity_mut::<&EntityHashSet>`
- The equivalent return type has changed from `Result<Vec<EntityMut>,
QueryEntityError>` to `Result<EntityHashMap<EntityMut>,
EntityFetchError>`. If necessary, you can still convert the
`EntityHashMap` into a `Vec`.
2024-10-07 15:21:40 +00:00
Vlady Veselinov
856cab56f9
Fix wrong link in error (#15672)
Hi y'all, I got an error that leads to a wrong link:
https://bevyengine.org/learn/errors/#b0002

It should be: https://bevyengine.org/learn/errors/b0002


![image](https://github.com/user-attachments/assets/863ae8cd-6a3b-4830-b125-2944a211a737)
2024-10-06 08:14:50 +00:00
Joona Aalto
25bfa80e60
Migrate cameras to required components (#15641)
# Objective

Yet another PR for migrating stuff to required components. This time,
cameras!

## Solution

As per the [selected
proposal](https://hackmd.io/tsYID4CGRiWxzsgawzxG_g#Combined-Proposal-1-Selected),
deprecate `Camera2dBundle` and `Camera3dBundle` in favor of `Camera2d`
and `Camera3d`.

Adding a `Camera` without `Camera2d` or `Camera3d` now logs a warning,
as suggested by Cart [on
Discord](https://discord.com/channels/691052431525675048/1264881140007702558/1291506402832945273).
I would personally like cameras to work a bit differently and be split
into a few more components, to avoid some footguns and confusing
semantics, but that is more controversial, and shouldn't block this core
migration.

## Testing

I ran a few 2D and 3D examples, and tried cameras with and without
render graphs.

---

## Migration Guide

`Camera2dBundle` and `Camera3dBundle` have been deprecated in favor of
`Camera2d` and `Camera3d`. Inserting them will now also insert the other
components required by them automatically.
2024-10-05 01:59:52 +00:00
urben1680
2e89e98931
Deprecate Events::oldest_id (#15658)
# Objective

Fixes #15617 

## Solution

The original author confirmed it was not intentional that both these
methods exist.

They do the same, one has the better implementation and the other the
better name.

## Testing

I just ran the unit tests of the module.

---

## Migration Guide

- Change usages of `Events::oldest_id` to `Events::oldest_event_count`
- If `Events::oldest_id` was used to get the actual oldest
`EventId::id`, note that the deprecated method never reliably did that
in the first place as the buffers may contain no id currently.
2024-10-05 01:35:44 +00:00
fluffiac
f0704cffa4
Allow a closure to be used as a required component default (#15269)
# Objective

Allow required component default values to be provided in-line.

```rust
#[derive(Component)]
#[require(
    FocusPolicy(block_focus_policy)
)]
struct SomeComponent;

fn block_focus_policy() -> FocusPolicy {
    FocusPolicy::Block
}
```

May now be expressed as:

```rust
#[derive(Component)]
#[require(
    FocusPolicy(|| FocusPolicy::Block)
)]
struct SomeComponent;
```

## Solution

Modified the #[require] proc macro to accept a closure. 

## Testing

Tested using my branch as a dependency, and switching between the inline
closure syntax and function syntax for a bunch of different components.
2024-10-04 00:34:39 +00:00
rewin
8bf5d99d86
Add method to remove component and all required components for removed component (#15026)
## Objective
The new Required Components feature (#14791) in Bevy allows spawning a
fixed set of components with a single method with cool require macro.
However, there's currently no corresponding method to remove all those
components together. This makes it challenging to keep insertion and
removal code in sync, especially for simple using cases.
```rust
#[derive(Component)]
#[require(Y)]
struct X;

#[derive(Component, Default)]
struct Y;

world.entity_mut(e).insert(X); // Spawns both X and Y
world.entity_mut(e).remove::<X>(); 
world.entity_mut(e).remove::<Y>(); // We need to manually remove dependencies without any sync with the `require` macro
```
## Solution
Simplifies component management by providing operations for removal
required components.
This PR introduces simple 'footgun' methods to removes all components of
this bundle and its required components.

Two new methods are introduced:
For Commands:
```rust
commands.entity(e).remove_with_requires::<B>();
```
For World:
```rust
world.entity_mut(e).remove_with_requires::<B>();
```

For performance I created new field in Bundels struct. This new field
"contributed_bundle_ids" contains cached ids for dynamic bundles
constructed from bundle_info.cintributed_components()

## Testing
The PR includes three test cases:

1. Removing a single component with requirements using World.
2. Removing a bundle with requirements using World.
3. Removing a single component with requirements using Commands.
4. Removing a single component with **runtime** requirements using
Commands

These tests ensure the feature works as expected across different
scenarios.

## Showcase
Example:
```rust
use bevy_ecs::prelude::*;

#[derive(Component)]
#[require(Y)]
struct X;

#[derive(Component, Default)]
#[require(Z)]
struct Y;

#[derive(Component, Default)]
struct Z;

#[derive(Component)]
struct W;

let mut world = World::new();

// Spawn an entity with X, Y, Z, and W components
let entity = world.spawn((X, W)).id();

assert!(world.entity(entity).contains::<X>());
assert!(world.entity(entity).contains::<Y>());
assert!(world.entity(entity).contains::<Z>());
assert!(world.entity(entity).contains::<W>());

// Remove X and required components Y, Z
world.entity_mut(entity).remove_with_requires::<X>();

assert!(!world.entity(entity).contains::<X>());
assert!(!world.entity(entity).contains::<Y>());
assert!(!world.entity(entity).contains::<Z>());

assert!(world.entity(entity).contains::<W>());
```

## Motivation for PR
#15580 

## Performance

I made simple benchmark
```rust
let mut world = World::default();
let entity = world.spawn_empty().id();

let steps = 100_000_000;

let start = std::time::Instant::now();
for _ in 0..steps {
    world.entity_mut(entity).insert(X);
    world.entity_mut(entity).remove::<(X, Y, Z, W)>();
}
let end = std::time::Instant::now();
println!("normal remove: {:?} ", (end - start).as_secs_f32());
println!("one remove: {:?} micros", (end - start).as_secs_f64() / steps as f64 * 1_000_000.0);

let start = std::time::Instant::now();
for _ in 0..steps {
    world.entity_mut(entity).insert(X);
    world.entity_mut(entity).remove_with_requires::<X>();
}
let end = std::time::Instant::now();
println!("remove_with_requires: {:?} ", (end - start).as_secs_f32());
println!("one remove_with_requires: {:?} micros", (end - start).as_secs_f64() / steps as f64 * 1_000_000.0);
```

Output:

CPU: Amd Ryzen 7 2700x

```bash
normal remove: 17.36135 
one remove: 0.17361348299999999 micros
remove_with_requires: 17.534006 
one remove_with_requires: 0.17534005400000002 micros
```

NOTE: I didn't find any tests or mechanism in the repository to update
BundleInfo after creating new runtime requirements with an existing
BundleInfo. So this PR also does not contain such logic.

## Future work (outside this PR)

Create cache system for fast removing components in "safe" mode, where
"safe" mode is remove only required components that will be no longer
required after removing root component.

---------

Co-authored-by: a.yamaev <a.yamaev@smartengines.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-10-03 20:35:08 +00:00
Chris Russell
46180a75f8
System param for dynamic resources (#15189)
# Objective

Support accessing dynamic resources in a dynamic system, including
accessing them by component id. This is similar to how dynamic
components can be queried using `Query<FilteredEntityMut>`.

## Solution

Create `FilteredResources` and `FilteredResourcesMut` types that act
similar to `FilteredEntityRef` and `FilteredEntityMut` and that can be
used as system parameters.

## Example

```rust
// Use `FilteredResourcesParamBuilder` to declare access to resources.
let system = (FilteredResourcesParamBuilder::new(|builder| {
    builder.add_read::<B>().add_read::<C>();
}),)
    .build_state(&mut world)
    .build_system(resource_system);

world.init_resource::<A>();
world.init_resource::<C>();

fn resource_system(res: FilteredResources) {
    // The resource exists, but we have no access, so we can't read it.
    assert!(res.get::<A>().is_none());
    // The resource doesn't exist, so we can't read it.
    assert!(res.get::<B>().is_none());
    // The resource exists and we have access, so we can read it.
    let c = res.get::<C>().unwrap();
    // The type parameter can be left out if it can be determined from use.
    let c: Res<C> = res.get().unwrap();
}
```

## Future Work

As a follow-up PR, `ReflectResource` can be modified to take `impl
Into<FilteredResources>`, similar to how `ReflectComponent` takes `impl
Into<FilteredEntityRef>`. That will allow dynamic resources to be
accessed using reflection.
2024-10-03 18:20:34 +00:00
Kristoffer Søholm
336c23c1aa
Rename observe to observe_entity on EntityWorldMut (#15616)
# Objective

The current observers have some unfortunate footguns where you can end
up confused about what is actually being observed. For apps you can
chain observe like `app.observe(..).observe(..)` which works like you
would expect, but if you try the same with world the first `observe()`
will return the `EntityWorldMut` for the created observer, and the
second `observe()` will only observe on the observer entity. It took
several hours for multiple people on discord to figure this out, which
is not a great experience.

## Solution

Rename `observe` on entities to `observe_entity`. It's slightly more
verbose when you know you have an entity, but it feels right to me that
observers for specific things have more specific naming, and it prevents
this issue completely.

Another possible solution would be to unify `observe` on `App` and
`World` to have the same kind of return type, but I'm not sure exactly
what that would look like.

## Testing

Simple name change, so only concern is docs really.

---


## Migration Guide

The `observe()` method on entities has been renamed to
`observe_entity()` to prevent confusion about what is being observed in
some cases.
2024-10-03 17:05:26 +00:00