# Objective
Current way to wire `Layer`s together using `layer.with(new_layer)` in
the `bevy_log` plugin is brittle and not flexible. As #17722
demonstrated, the current solution makes it very hard to do any kind of
advanced wiring, as the type system of `tracing::Subscriber` gets in the
way very quickly (the type of each new layer depends on the type of the
previous ones). We want to make it easier to have more complex wiring of
`Layers`. It would be hard to solve #19085 without it
## Solution
It aims to be functionally equivalent.
- Replace of using `layer.with(new_layer)` . We now add `layer.boxed()`
to a `Vec<BoxedLayer>`. It is a solution recommended by
`tracing_subscriber::Layer` for complex wiring cases (See
https://docs.rs/tracing-subscriber/latest/tracing_subscriber/layer/index.html#runtime-configuration-with-layers)
- Do some refactoring and clean up that is now enabled by the new
solution
## Testing
- Ran CI locally on Linux
- Ran the logs examples
- Need people familiar with the features `trace`, `tracing-chrome`,
`tracing-tracy` to check that it still works as expected
- Need people with access to `ios`, `android` and `wasm` to check it as
well.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
The LogPlugin now allows overriding the default
`tracing_subscriber::fmt::Layer` through a new `fmt_layer` option. This
enables customization of the default log output format without having to
replace the entire logging system.
For example, to disable timestamps in the log output:
```rust
fn fmt_layer(_app: &mut App) -> Option<bevy::log::BoxedFmtLayer> {
Some(Box::new(
bevy::log::tracing_subscriber::fmt::Layer::default()
.without_time()
.with_writer(std::io::stderr),
))
}
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(bevy::log::LogPlugin {
fmt_layer,
..default()
}))
.run();
}
```
This is different from the existing `custom_layer` option, because that
option _adds_ additional layers to the subscriber, but can't modify the
default formatter layer (at least, not to my knowledge).
I almost always disable timestamps in my Bevy logs, and usually also
tweak other default log formatting (such as `with_span_events`), which
made it so that I always had to disable the default logger. This allows
me to use everything the Bevy logger supports (including tracy support),
while still formatting the default logs the way I like them.
---------
Signed-off-by: Jean Mertz <git@jeanmertz.com>
# Objective
- Contributes to #11478
## Solution
- Made `bevy_utils::tracing` `doc(hidden)`
- Re-exported `tracing` from `bevy_log` for end-users
- Added `tracing` directly to crates that need it.
## Testing
- CI
---
## Migration Guide
If you were importing `tracing` via `bevy::utils::tracing`, instead use
`bevy::log::tracing`. Note that many items within `tracing` are also
directly re-exported from `bevy::log` as well, so you may only need
`bevy::log` for the most common items (e.g., `warn!`, `trace!`, etc.).
This also applies to the `log_once!` family of macros.
## Notes
- While this doesn't reduce the line-count in `bevy_utils`, it further
decouples the internal crates from `bevy_utils`, making its eventual
removal more feasible in the future.
- I have just imported `tracing` as we do for all dependencies. However,
a workspace dependency may be more appropriate for version management.
# Objective
Fixes#16104
## Solution
I removed all instances of `:?` and put them back one by one where it
caused an error.
I removed some bevy_utils helper functions that were only used in 2
places and don't add value. See: #11478
## Testing
CI should catch the mistakes
## Migration Guide
`bevy::utils::{dbg,info,warn,error}` were removed. Use
`bevy::utils::tracing::{debug,info,warn,error}` instead.
---------
Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net>
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/12597
The current tracing customization option (the `update_subscriber` field)
was basically unusable because it provides a `dyn Subscriber` and most
layers require a `Subscriber` that also implements `for<'a>
LookupSpan<'a, Data=Data<'a>>`, so it was impossible to add a layer on
top of the `dyn Subscriber`.
This PR provides an alternative way of adding additional tracing layers
to the LogPlugin by instead creating an `Option<Layer>`.
This is enough for most situations because `Option<Layer>` and
`Vec<Layer>` both implement `Layer`.
## Solution
- Replace the `update_subscriber` field of `LogPlugin` with a
`custom_layer` field which is function pointer returning an
`Option<BoxedLayer>`
- Update the examples to showcase that this works:
- with multiple additional layers
- with Layers that were previously problematic, such as
`bevy::log::tracing_subscriber::fmt::layer().with_file(true)` (mentioned
in the issue)
Note that in the example this results in duplicate logs, since we have
our own layer on top of the default `fmt_layer` added in the LogPlugin;
maybe in the future we might want to provide a single one? Or to let the
user customize the default `fmt_layer` ? I still think this change is an
improvement upon the previous solution, which was basically broken.
---
## Changelog
> This section is optional. If this was a trivial fix, or has no
externally-visible impact, you can delete this section.
- The `LogPlugin`'s `update_subscriber` field has been replaced with
`custom_layer` to allow the user to flexibly add a `tracing::Layer` to
the layer stack
## Migration Guide
- The `LogPlugin`'s `update_subscriber` field has been replaced with
`custom_layer`
---------
Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com>
# Objective
In my library,
[`bevy_dev_console`](https://github.com/doonv/bevy_dev_console) I need
access to `App` within `LogPlugin::update_subscriber` in order to
communicate with the `App` from my custom `Layer`.
## Solution
Give access to `App`.
---
## Changelog
- Added access to `App` within `LogPlugin::update_subscriber`
## Migration Guide
`LogPlugin::update_subscriber` now has a `&mut App` parameter. If you
don't need access to `App`, you can ignore the parameter with an
underscore (`_`).
```diff,rust
- fn update_subscriber(subscriber: BoxedSubscriber) -> BoxedSubscriber {
+ fn update_subscriber(_: &mut App, subscriber: BoxedSubscriber) -> BoxedSubscriber {
Box::new(subscriber.with(CustomLayer))
}
```
# Objective
This PR is heavily inspired by
https://github.com/bevyengine/bevy/pull/7682
It aims to solve the same problem: allowing the user to extend the
tracing subscriber with extra layers.
(in my case, I'd like to use `use
metrics_tracing_context::{MetricsLayer, TracingContextLayer};`)
## Solution
I'm proposing a different api where the user has the opportunity to take
the existing `subscriber` and apply any transformations on it.
---
## Changelog
- Added a `update_subscriber` option on the `LogPlugin` that lets the
user modify the `subscriber` (for example to extend it with more tracing
`Layers`
## Migration Guide
> This section is optional. If there are no breaking changes, you can
delete this section.
- Added a new field `update_subscriber` in the `LogPlugin`
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
