# Objective
Ability to use `ReflectComponent` methods in dynamic type contexts with no access to `&World`.
This problem occurred to me when wanting to apply reflected types to an entity where the `&World` reference was already consumed by query iterator leaving only `EntityMut`.
## Solution
- Remove redundant `EntityMut` or `EntityRef` lookup from `World` and `Entity` in favor of taking `EntityMut` directly in `ReflectComponentFns`.
- Added `RefectComponent::contains` to determine without panic whether `apply` can be used.
## Changelog
- Changed function signatures of `ReflectComponent` methods, `apply`, `remove`, `contains`, and `reflect`.
## Migration Guide
- Call `World::entity` before calling into the changed `ReflectComponent` methods, most likely user already has a `EntityRef` or `EntityMut` which was being queried redundantly.
# Objective
- Dynamic scene builder can build scenes without components, if they didn't have any matching the type registry
- Those entities are not really useful in the final `DynamicScene`
## Solution
- Add a method `remove_empty_entities` that will remove empty entities. It's not called by default when calling `build`, I'm not sure if that's a good idea or not.
# Objective
Fixes#6059, changing all incorrect occurrences of ``id`` in the ``entity`` module to ``index``:
* struct level documentation,
* ``id`` struct field,
* ``id`` method and its documentation.
## Solution
Renaming and verifying using CI.
Co-authored-by: Edvin Kjell <43633999+Edwox@users.noreply.github.com>
# Objective
Currently, `DynamicSceneBuilder` keeps track of entities via a `HashMap`. This has an unintended side-effect in that, when building the full `DynamicScene`, we aren't guaranteed any particular order.
In other words, inserting Entity A then Entity B can result in either `[A, B]` or `[B, A]`. This can be rather annoying when running tests on scenes generated via the builder as it will work sometimes but not other times. There's also the potential that this might unnecessarily clutter up VCS diffs for scene files (assuming they had an intentional order).
## Solution
Store `DynamicSceneBuilder`'s entities in a `Vec` rather than a `HashMap`.
---
## Changelog
* Stablized entity order in `DynamicSceneBuilder` (0.9.0-dev)
# Objective
- make it easier to build dynamic scenes
## Solution
- add a builder to create a dynamic scene from a world. it can extract an entity or an iterator of entities
- alternative to #6013, leaving the "hierarchy iteration" part to #6185 which does it better
- alternative to #6004
- using a builder makes it easier to chain several extractions
