# 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`.
# Objective
- Fixes#15106
## Solution
- Trivial refactor to rename the method. The duplicate method `push` was
removed as well. This will simpify the API and make the semantics more
clear. `Add` implies that the action happens immediately, whereas in
reality, the command is queued to be run eventually.
- `ChildBuilder::add_command` has similarly been renamed to
`queue_command`.
## Testing
Unit tests should suffice for this simple refactor.
---
## Migration Guide
- `Commands::add` and `Commands::push` have been replaced with
`Commnads::queue`.
- `ChildBuilder::add_command` has been renamed to
`ChildBuilder::queue_command`.
# Objective
- Makes naming between add_child and add_children more consistent
- Fixes#15101
## Solution
renamed push_children to add_children
## Testing
- Did you test these changes? If so, how?
Ran tests + grep search for any instance of `push_child`
- Are there any parts that need more testing?
- How can other people (reviewers) test your changes? Is there anything
specific they need to know?
- If relevant, what platforms did you test these changes on, and are
there any important ones you can't test?
ran tests on WSL2
---
## 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
rename any use of `push_children()` to the updated `add_children()`
# Objective
Implement `BuildChildrenTransformExt` for `EntityWorldMut`, which is
useful when working directly with a mutable `World` ref.
## Solution
I realize this isn't the most optimal implementation in that it doesn't
reuse the existing entity location for the child, but it is terse and
reuses the existing code. I can address that if needed.
## Testing
I only tested locally. There are no tests for `set_parent_in_place` and
`remove_parent_in_place` currently, but I can add some.
---
## Changelog
`BuildChildrenTransformExt` implemented for `EntityWorldMut`.
# Objective
Part of https://github.com/bevyengine/bevy/issues/13529
Helps https://github.com/bevyengine/bevy/pull/13533
Splitting up `bevy_transform` makes it easier to selectively include or
exclude parts of it in such a way that it's possible to include only a
small part with a small dependency tree.
## Solution
Make the crate more modular.
---------
Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
# Objective
Fixes https://github.com/bevyengine/bevy/issues/11628
## Migration Guide
`Command` and `CommandQueue` have migrated from `bevy_ecs::system` to
`bevy_ecs::world`, so `use bevy_ecs::world::{Command, CommandQueue};`
when necessary.
# Objective
It would be convenient to be able to call functions with `Commands` as a
parameter without having to move your own instance of `Commands`. Since
this struct is composed entirely of references, we can easily get an
owned instance of `Commands` by shortening the lifetime.
## Solution
Add `Commands::reborrow`, `EntiyCommands::reborrow`, and
`Deferred::reborrow`, which returns an owned version of themselves with
a shorter lifetime.
Remove unnecessary lifetimes from `EntityCommands`. The `'w` and `'s`
lifetimes only have to be separate for `Commands` because it's used as a
`SystemParam` -- this is not the case for `EntityCommands`.
---
## Changelog
Added `Commands::reborrow`. This is useful if you have `&mut Commands`
but need `Commands`. Also added `EntityCommands::reborrow` and
`Deferred:reborrow` which serve the same purpose.
## Migration Guide
The lifetimes for `EntityCommands` have been simplified.
```rust
// Before (Bevy 0.12)
struct MyStruct<'w, 's, 'a> {
commands: EntityCommands<'w, 's, 'a>,
}
// After (Bevy 0.13)
struct MyStruct<'a> {
commands: EntityCommands<'a>,
}
```
The method `EntityCommands::commands` now returns `Commands` rather than
`&mut Commands`.
```rust
// Before (Bevy 0.12)
let commands = entity_commands.commands();
commands.spawn(...);
// After (Bevy 0.13)
let mut commands = entity_commands.commands();
commands.spawn(...);
```
# Objective
- Fixes#11187
## Solution
- Rename the `AddChild` struct to `PushChild`
- Rename the `AddChildInPlace` struct to `PushChildInPlace`
## Migration Guide
The struct `AddChild` has been renamed to `PushChild`, and the struct
`AddChildInPlace` has been renamed to `PushChildInPlace`.
# Objective
- Make the implementation order consistent between all sources to fit
the order in the trait.
## Solution
- Change the implementation order.
# Objective
I've been collecting some mistakes in the documentation and fixed them
---------
Co-authored-by: Emi <emanuel.boehm@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
- Fixes#8811 .
## Solution
- Rename "write" method to "apply" in Command trait definition.
- Rename other implementations of command trait throughout bevy's code
base.
---
## Changelog
- Changed: `Command::write` has been changed to `Command::apply`
- Changed: `EntityCommand::write` has been changed to
`EntityCommand::apply`
## Migration Guide
- `Command::write` implementations need to be changed to implement
`Command::apply` instead. This is a mere name change, with no further
actions needed.
- `EntityCommand::write` implementations need to be changed to implement
`EntityCommand::apply` instead. This is a mere name change, with no
further actions needed.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- `apply_system_buffers` is an unhelpful name: it introduces a new
internal-only concept
- this is particularly rough for beginners as reasoning about how
commands work is a critical stumbling block
## Solution
- rename `apply_system_buffers` to the more descriptive `apply_deferred`
- rename related fields, arguments and methods in the internals fo
bevy_ecs for consistency
- update the docs
## Changelog
`apply_system_buffers` has been renamed to `apply_deferred`, to more
clearly communicate its intent and relation to `Deferred` system
parameters like `Commands`.
## Migration Guide
- `apply_system_buffers` has been renamed to `apply_deferred`
- the `apply_system_buffers` method on the `System` trait has been
renamed to `apply_deferred`
- the `is_apply_system_buffers` function has been replaced by
`is_apply_deferred`
- `Executor::set_apply_final_buffers` is now
`Executor::set_apply_final_deferred`
- `Schedule::apply_system_buffers` is now `Schedule::apply_deferred`
---------
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
Links in the api docs are nice. I noticed that there were several places
where structs / functions and other things were referenced in the docs,
but weren't linked. I added the links where possible / logical.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
Documentation should no longer be using pre-stageless terminology to
avoid confusion.
## Solution
- update all docs referring to stages to instead refer to sets/schedules
where appropriate
- also mention `apply_system_buffers` for anything system-buffer-related
that previously referred to buffers being applied "at the end of a
stage"
# Objective
It is often necessary to update an entity's parent
while keeping its GlobalTransform static. Currently
it is cumbersome and error-prone (two questions in
the discord `#help` channel in the past week)
- Part 2, resolves#5475
- Builds on: #7020.
## Solution
- Added the `BuildChildrenTransformExt` trait, it is part
of `bevy::prelude` and adds the following methods to `EntityCommands`:
- `set_parent_in_place`: Change the parent of an entity and
update its `Transform` in order to preserve its `GlobalTransform` after the parent change
- `remove_parent_in_place`: Remove an entity from a hierarchy,
while preserving its `GlobalTransform`.
---
## Changelog
- Added the `BuildChildrenTransformExt` trait, it is part
of `bevy::prelude` and adds the following methods to `EntityCommands`:
- `set_parent_in_place`: Change the parent of an entity and
update its `Transform` in order to preserve its `GlobalTransform` after the parent change
- `remove_parent_in_place`: Remove an entity from a hierarchy,
while preserving its `GlobalTransform`.
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
