Reflection for External Crates

[jnhyatt]

I've got a component I'm trying to reflect (I want to modify its contents at runtime through bevy_editor_pls), but #[derive(Reflect)] fails because the struct has a chrono::DateTime<Utc> member. I can't manually implement Reflect for it because of Rust's coherence rules. Here are the options I see:

1. Replace usages of chrono types in my struct with something that can be reflected
2. Derive Reflect in the chrono crate and lock it behind a bevy_reflect feature and pull request
3. Derive Reflect in the bevy_reflect crate and lock it behind a chrono feature and pull request
4. Ask for guidance on Bevy's GitHub discussions page

Options 1-3 seem overly intrusive:

1. I shouldn't have to sacrifice features for functionality
2. Bevy is unrelated to chrono
3. Bevy does not depend on chrono

So I opted for option 4 in the hopes that Bevy has some other way to do this that I haven't yet happened upon. Any advice would be appreciated!

[nicopap]

You can't currently reflect a foreign type, you would need to #[reflect(ignore)] it. Although there is some work toward it, as seen in #6042.

A workaround is possible using the bevy_mod_component_mirror crate (disclaimer: am the author)

[jnhyatt]

Thanks, not sure why my searching didn't turn up that issue. I'll take a look at your crate, is it exclusively for rapier?

[nicopap]

It's not exclusive to rapier. Only the pre-made ready-to-use stuff. For your components, you'll have to follow the instructions in the "Implement your own mirrors" section

[jnhyatt]

Thanks, very much appreciated!