# Objective
Currently, `FromReflect` makes a couple assumptions:
* Ignored fields must implement `Default`
* Active fields must implement `FromReflect`
* The reflected must be fully populated for active fields (can't use an empty `DynamicStruct`)
However, one or both of these requirements might be unachievable, such as for external types. In these cases, it might be nice to tell `FromReflect` to use a custom default.
## Solution
Added the `#[reflect(default)]` derive helper attribute. This attribute can be applied to any field (ignored or not) and will allow a default value to be specified in place of the regular `from_reflect()` call.
It takes two forms: `#[reflect(default)]` and `#[reflect(default = "some_func")]`. The former specifies that `Default::default()` should be used while the latter specifies that `some_func()` should be used. This is pretty much [how serde does it](https://serde.rs/field-attrs.html#default).
### Example
```rust
#[derive(Reflect, FromReflect)]
struct MyStruct {
// Use `Default::default()`
#[reflect(default)]
foo: String,
// Use `get_bar_default()`
#[reflect(default = "get_bar_default")]
#[reflect(ignore)]
bar: usize,
}
fn get_bar_default() -> usize {
123
}
```
### Active Fields
As an added benefit, this also allows active fields to be completely missing from their dynamic object. This is because the attribute tells `FromReflect` how to handle missing active fields (it still tries to use `from_reflect` first so the `FromReflect` trait is still required).
```rust
let dyn_struct = DynamicStruct::default();
// We can do this without actually including the active fields since they have `#[reflect(default)]`
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
```
### Container Defaults
Also, with the addition of #3733, people will likely start adding `#[reflect(Default)]` to their types now. Just like with the fields, we can use this to mark the entire container as "defaultable". This grants us the ability to completely remove the field markers altogether if our type implements `Default` (and we're okay with fields using that instead of their own `Default` impls):
```rust
#[derive(Reflect, FromReflect)]
#[reflect(Default)]
struct MyStruct {
foo: String,
#[reflect(ignore)]
bar: usize,
}
impl Default for MyStruct {
fn default() -> Self {
Self {
foo: String::from("Hello"),
bar: 123,
}
}
}
// Again, we can now construct this from nothing pretty much
let dyn_struct = DynamicStruct::default();
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
```
Now if _any_ field is missing when using `FromReflect`, we simply fallback onto the container's `Default` implementation.
This behavior can be completely overridden on a per-field basis, of course, by simply defining those same field attributes like before.
### Related
* #3733
* #1395
* #2377
---
## Changelog
* Added `#[reflect(default)]` field attribute for `FromReflect`
* Allows missing fields to be given a default value when using `FromReflect`
* `#[reflect(default)]` - Use the field's `Default` implementation
* `#[reflect(default = "some_fn")]` - Use a custom function to get the default value
* Allow `#[reflect(Default)]` to have a secondary usage as a container attribute
* Allows missing fields to be given a default value based on the container's `Default` impl when using `FromReflect`
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Fixes#4353. Fixes#4431. Picks up fixes for a panic for `gilrs` when `getGamepads()` is not available.
## Solution
Update the `gilrs` to `v0.9.0`. Changelog can be seen here: dba36f9186
EDIT: Updated `uuid` to 1.1 to avoid duplicate dependencies. Added `nix`'s two dependencies as exceptions until `rodio` updates their deps.
# Objective
Debugging reflected types can be somewhat frustrating since all `dyn Reflect` trait objects return something like `Reflect(core::option::Option<alloc::string::String>)`.
It would be much nicer to be able to see the actual value— or even use a custom `Debug` implementation.
## Solution
Added `Reflect::debug` which allows users to customize the debug output. It sets defaults for all `ReflectRef` subtraits and falls back to `Reflect(type_name)` if no `Debug` implementation was registered.
To register a custom `Debug` impl, users can add `#[reflect(Debug)]` like they can with other traits.
### Example
Using the following structs:
```rust
#[derive(Reflect)]
pub struct Foo {
a: usize,
nested: Bar,
#[reflect(ignore)]
_ignored: NonReflectedValue,
}
#[derive(Reflect)]
pub struct Bar {
value: Vec2,
tuple_value: (i32, String),
list_value: Vec<usize>,
// We can't determine debug formatting for Option<T> yet
unknown_value: Option<String>,
custom_debug: CustomDebug
}
#[derive(Reflect)]
#[reflect(Debug)]
struct CustomDebug;
impl Debug for CustomDebug {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "This is a custom debug!")
}
}
pub struct NonReflectedValue {
_a: usize,
}
```
We can do:
```rust
let value = Foo {
a: 1,
_ignored: NonReflectedValue { _a: 10 },
nested: Bar {
value: Vec2::new(1.23, 3.21),
tuple_value: (123, String::from("Hello")),
list_value: vec![1, 2, 3],
unknown_value: Some(String::from("World")),
custom_debug: CustomDebug
},
};
let reflected_value: &dyn Reflect = &value;
println!("{:#?}", reflected_value)
```
Which results in:
```rust
Foo {
a: 2,
nested: Bar {
value: Vec2(
1.23,
3.21,
),
tuple_value: (
123,
"Hello",
),
list_value: [
1,
2,
3,
],
unknown_value: Reflect(core::option::Option<alloc::string::String>),
custom_debug: This is a custom debug!,
},
}
```
Notice that neither `Foo` nor `Bar` implement `Debug`, yet we can still deduce it. This might be a concern if we're worried about leaking internal values. If it is, we might want to consider a way to exclude fields (possibly with a `#[reflect(hide)]` macro) or make it purely opt in (as opposed to the default implementation automatically handled by ReflectRef subtraits).
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Allow `Box<dyn Reflect>` to be converted into a `Box<dyn MyTrait>` using the `#[reflect_trait]` macro. The other methods `get` and `get_mut` only provide a reference to the reflected object.
## Solution
Add a `get_boxed` method to the `Reflect***` struct generated by the `#[reflect_trait]` macro. This method takes in a `Box<dyn Reflect>` and returns a `Box<dyn MyTrait>`.
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
Quick followup to #4712.
While updating some [other PRs](https://github.com/bevyengine/bevy/pull/4218), I realized the `ReflectTraits` struct could be improved. The issue with the current implementation is that `ReflectTraits::get_xxx_impl(...)` returns just the _logic_ to the corresponding `Reflect` trait method, rather than the entire function.
This makes it slightly more annoying to manage since the variable names need to be consistent across files. For example, `get_partial_eq_impl` uses a `value` variable. But the name "value" isn't defined in the `get_partial_eq_impl` method, it's defined in three other methods in a completely separate file.
It's not likely to cause any bugs if we keep it as it is since differing variable names will probably just result in a compile error (except in very particular cases). But it would be useful to someone who wanted to edit/add/remove a method.
## Solution
Made `get_hash_impl`, `get_partial_eq_impl` and `get_serialize_impl` return the entire method implementation for `reflect_hash`, `reflect_partial_eq`, and `serializable`, respectively.
As a result of this, those three `Reflect` methods were also given default implementations. This was fairly simple to do since all three could just be made to return `None`.
---
## Changelog
* Small cleanup/refactor to `ReflectTraits` in `bevy_reflect_derive`
* Gave `Reflect::reflect_hash`, `Reflect::reflect_partial_eq`, and `Reflect::serializable` default implementations
# Objective
The `bevy_reflect_derive` crate is not the cleanest or easiest to follow/maintain. The `lib.rs` file is especially difficult with over 1000 lines of code written in a confusing order. This is just a result of growth within the crate and it would be nice to clean it up for future work.
## Solution
Split `bevy_reflect_derive` into many more submodules. The submodules include:
* `container_attributes` - Code relating to container attributes
* `derive_data` - Code relating to reflection-based derive metadata
* `field_attributes` - Code relating to field attributes
* `impls` - Code containing actual reflection implementations
* `reflect_value` - Code relating to reflection-based value metadata
* `registration` - Code relating to type registration
* `utility` - General-purpose utility functions
This leaves the `lib.rs` file to contain only the public macros, making it much easier to digest (and fewer than 200 lines).
By breaking up the code into smaller modules, we make it easier for future contributors to find the code they're looking for or identify which module best fits their own additions.
### Metadata Structs
This cleanup also adds two big metadata structs: `ReflectFieldAttr` and `ReflectDeriveData`. The former is used to store all attributes for a struct field (if any). The latter is used to store all metadata for struct-based derive inputs.
Both significantly reduce code duplication and make editing these macros much simpler. The tradeoff is that we may collect more metadata than needed. However, this is usually a small thing (such as checking for attributes when they're not really needed or creating a `ReflectFieldAttr` for every field regardless of whether they actually have an attribute).
We could try to remove these tradeoffs and squeeze some more performance out, but doing so might come at the cost of developer experience. Personally, I think it's much nicer to create a `ReflectFieldAttr` for every field since it means I don't have to do two `Option` checks. Others may disagree, though, and so we can discuss changing this either in this PR or in a future one.
### Out of Scope
_Some_ documentation has been added or improved, but ultimately good docs are probably best saved for a dedicated PR.
## 🔍 Focus Points (for reviewers)
I know it's a lot to sift through, so here is a list of **key points for reviewers**:
- The following files contain code that was mostly just relocated:
- `reflect_value.rs`
- `registration.rs`
- `container_attributes.rs` was also mostly moved but features some general cleanup (reducing nesting, removing hardcoded strings, etc.) and lots of doc comments
- Most impl logic was moved from `lib.rs` to `impls.rs`, but they have been significantly modified to use the new `ReflectDeriveData` metadata struct in order to reduce duplication.
- `derive_data.rs` and `field_attributes.rs` contain almost entirely new code and should probably be given the most attention.
- Likewise, `from_reflect.rs` saw major changes using `ReflectDeriveData` so it should also be given focus.
- There was no change to the `lib.rs` exports so the end-user API should be the same.
## Prior Work
This task was initially tackled by @NathanSWard in #2377 (which was closed in favor of this PR), so hats off to them for beating me to the punch by nearly a year!
---
## Changelog
* **[INTERNAL]** Split `bevy_reflect_derive` into smaller submodules
* **[INTERNAL]** Add `ReflectFieldAttr`
* **[INTERNAL]** Add `ReflectDeriveData`
* Add `BevyManifest::get_path_direct()` method (`bevy_macro_utils`)
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
Relevant issue: #4474
Currently glam types implement Reflect as a value, which is problematic for reflection, making scripting/editor work much more difficult. This PR re-implements them as structs.
## Solution
Added a new proc macro, `impl_reflect_struct`, which replaces `impl_reflect_value` and `impl_from_reflect_value` for glam types. This macro could also be used for other types, but I don't know of any that would require it. It's specifically useful for foreign types that cannot derive Reflect normally.
---
## Changelog
### Added
- `impl_reflect_struct` proc macro
### Changed
- Glam reflect impls have been replaced with `impl_reflect_struct`
- from_reflect's `impl_struct` altered to take an optional custom constructor, allowing non-default non-constructible foreign types to use it
- Calls to `impl_struct` altered to conform to new signature
- Altered glam types (All vec/mat combinations) have a different serialization structure, as they are reflected differently now.
## Migration Guide
This will break altered glam types serialized to RON scenes, as they will expect to be serialized/deserialized as structs rather than values now. A future PR to add custom serialization for non-value types is likely on the way to restore previous behavior. Additionally, calls to `impl_struct` must add a `None` parameter to the end of the call to restore previous behavior.
Co-authored-by: PROMETHIA-27 <42193387+PROMETHIA-27@users.noreply.github.com>
# Objective
Reduce from scratch build time.
## Solution
Reduce the size of the critical path by removing dependencies between crates where not necessary. For `cargo check --no-default-features` this reduced build time from ~51s to ~45s. For some commits I am not completely sure if the tradeoff between build time reduction and convenience caused by the commit is acceptable. If not, I can drop them.
Support for deriving `TypeUuid` for types with generics was initially added in https://github.com/bevyengine/bevy/pull/2044 but later reverted https://github.com/bevyengine/bevy/pull/2204 because it lead to `MyStruct<A>` and `MyStruct<B>` having the same type uuid.
This PR fixes this by generating code like
```rust
#[derive(TypeUuid)]
#[uuid = "69b09733-a21a-4dab-a444-d472986bd672"]
struct Type<T>(T);
impl<T: TypeUuid> TypeUuid for Type<T> {
const TYPE_UUID: TypeUuid = generate_compound_uuid(Uuid::from_bytes([/* 69b0 uuid */]), T::TYPE_UUID);
}
```
where `generate_compound_uuid` will XOR the non-metadata bits of the two UUIDs.
Co-authored-by: XBagon <xbagon@outlook.de>
Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
# Objective
Trait objects that have `Reflect` as a supertrait cannot be upcast to a `dyn Reflect`.
Attempting something like:
```rust
trait MyTrait: Reflect {
// ...
}
fn foo(value: &dyn MyTrait) {
let reflected = value as &dyn Reflect; // Error!
// ...
}
```
Results in `error[E0658]: trait upcasting coercion is experimental`.
The reason this is important is that a lot of `bevy_reflect` methods require a `&dyn Reflect`. This is trivial with concrete types, but if we don't know the concrete type (we only have the trait object), we can't use these methods. For example, we couldn't create a `ReflectSerializer` for the type since it expects a `&dyn Reflect` value— even though we should be able to.
## Solution
Add `as_reflect` and `as_reflect_mut` to `Reflect` to allow upcasting to a `dyn Reflect`:
```rust
trait MyTrait: Reflect {
// ...
}
fn foo(value: &dyn MyTrait) {
let reflected = value.as_reflect();
// ...
}
```
## Alternatives
We could defer this type of logic to the crate/user. They can add these methods to their trait in the same exact way we do here. The main benefit of doing it ourselves is it makes things convenient for them (especially when using the derive macro).
We could also create an `AsReflect` trait with a blanket impl over all reflected types, however, I could not get that to work for trait objects since they aren't sized.
---
## Changelog
- Added trait method `Reflect::as_reflect(&self)`
- Added trait method `Reflect::as_reflect_mut(&mut self)`
## Migration Guide
- Manual implementors of `Reflect` will need to add implementations for the methods above (this should be pretty easy as most cases just need to return `self`)
A couple more uncontroversial changes extracted from #3886.
* Enable full feature of syn
It is necessary for the ItemFn and ItemTrait type. Currently it is indirectly
enabled through the tracing dependency of bevy_utils, but this may no
longer be the case in the future.
* Remove unused function from bevy_macro_utils
# Objective
The `#[reflect_trait]` macro did not maintain the visibility of its trait. It also did not make its accessor methods public, which made them inaccessible outside the current module.
## Solution
Made the `Reflect***` struct match the visibility of its trait and made both the `get` and `get_mut` methods always public.
What is says on the tin.
This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance.
that said, deriving `Default` for a couple of structs is a nice easy win
Dynamic types (`DynamicStruct`, `DynamicTupleStruct`, `DynamicTuple`, `DynamicList` and `DynamicMap`) are used when deserializing scenes, but currently they can only be applied to existing concrete types. This leads to issues when trying to spawn non trivial deserialized scene.
For components, the issue is avoided by requiring that reflected components implement ~~`FromResources`~~ `FromWorld` (or `Default`). When spawning, a new concrete type is created that way, and the dynamic type is applied to it. Unfortunately, some components don't have any valid implementation of these traits.
In addition, any `Vec` or `HashMap` inside a component will panic when a dynamic type is pushed into it (for instance, `Text` panics when adding a text section).
To solve this issue, this PR adds the `FromReflect` trait that creates a concrete type from a dynamic type that represent it, derives the trait alongside the `Reflect` trait, drops the ~~`FromResources`~~ `FromWorld` requirement on reflected components, ~~and enables reflection for UI and Text bundles~~. It also adds the requirement that fields ignored with `#[reflect(ignore)]` implement `Default`, since we need to initialize them somehow.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Objective
During work on #3009 I've found that not all jobs use actions-rs, and therefore, an previous version of Rust is used for them. So while compilation and other stuff can pass, checking markup and Android build may fail with compilation errors.
Solution
This PR adds `action-rs` for any job running cargo, and updates the edition to 2021.
A few minor changes to fix warnings emitted from clippy on the nightly toolchain, including redundant_allocation, unwrap_or_else_default, and collapsible_match, fixes#2698
This relicenses Bevy under the dual MIT or Apache-2.0 license. For rationale, see #2373.
* Changes the LICENSE file to describe the dual license. Moved the MIT license to docs/LICENSE-MIT. Added the Apache-2.0 license to docs/LICENSE-APACHE. I opted for this approach over dumping both license files at the root (the more common approach) for a number of reasons:
* Github links to the "first" license file (LICENSE-APACHE) in its license links (you can see this in the wgpu and rust-analyzer repos). People clicking these links might erroneously think that the apache license is the only option. Rust and Amethyst both use COPYRIGHT or COPYING files to solve this problem, but this creates more file noise (if you do everything at the root) and the naming feels way less intuitive.
* People have a reflex to look for a LICENSE file. By providing a single license file at the root, we make it easy for them to understand our licensing approach.
* I like keeping the root clean and noise free
* There is precedent for putting the apache and mit license text in sub folders (amethyst)
* Removed the `Copyright (c) 2020 Carter Anderson` copyright notice from the MIT license. I don't care about this attribution, it might make license compliance more difficult in some cases, and it didn't properly attribute other contributors. We shoudn't replace it with something like "Copyright (c) 2021 Bevy Contributors" because "Bevy Contributors" is not a legal entity. Instead, we just won't include the copyright line (which has precedent ... Rust also uses this approach).
* Updates crates to use the new "MIT OR Apache-2.0" license value
* Removes the old legion-transform license file from bevy_transform. bevy_transform has been its own, fully custom implementation for a long time and that license no longer applies.
* Added a License section to the main readme
* Updated our Bevy Plugin licensing guidelines.
As a follow-up we should update the website to properly describe the new license.
Closes#2373
Fixes#2037 (and then some)
Problem:
- `TypeUuid`, `RenderResource`, and `Bytes` derive macros did not properly handle generic structs.
Solution:
- Rework the derive macro implementations to handle the generics.
Fixes#1100
Implementors must make sure that `Reflect::any` and `Reflect::any_mut` both return the `self` reference passed in (both for logical correctness and downcast safety).
* Rename reflect 'hash' method to 'reflect_hash' to avoid colliding with std:#️⃣:Hash::hash to resolve#943.
* Rename partial_eq to reflect_partial_eq to avoid collisions with implementations of PartialEq on primitives.
