Feature: Hot-reload / Runtime interpretor for debug mode

[wrapperup]

Love the library, it's really nice!

This would add an optional feature that allows maud to embed a runtime parser/interpreter that can read its own macro block from Rust source code. This runtime templating is limited in scope, meaning that changes to data, bindings, etc will require a recompile, but other changes could be done by interpreting the macro block at runtime (which IMO covers a lot of iteration time). This is definitely a bigger task with multiple steps, but I think it can be a really useful feature.

This is something Dioxus has implemented as a CLI tool, and I made a proof-of-concept implementation html_hotreload! (renamed to html! in the video) macro that uses maud's parser to generate a runtime instead that also parses itself at runtime (inception...).

maud_hotreload.mp4

Is this something you'd be interested in including with maud as an optional feature, or is it out of scope for maud? I think it could be it's own crate with a small refactor to expose maud's proc-macro/parser internals.

Either way, thanks for the useful library!

[lambda-fairy]

Hi @wrapperup, thanks for sharing! That looks really cool.

I think I'm too busy right now to review major changes like this. Feel free to iterate out-of-tree!

[untitaker]

i'd definitely be interested in a version of this that works with axum and my own htmx frontend, but i can't figure out which of the dioxus crates offers this functionality, or if the code for that demo is public somewhere.

[untitaker]

Found the code: https://github.com/wrapperup/maud/commits/hotreload-prototype/

[wrapperup]

Found the code: https://github.com/wrapperup/maud/commits/hotreload-prototype/

Yeah, the code there is nowhere near finished and it pulls in some extra unneeded dependencies, so I'm not sure if it would be a good idea to use it in the current state, but feel free to use it as a reference :).

If this work is something you're interested in continuing, the main blocker is splitting out maud's proc-macro internals into a different crate, making a bit of it public and upstreaming that (you can see some of the work splitting maud_macros out into maud_macros_impl).

Ideally, the hot-reload functionality would be a separate crate/module that depends on maud_macros_impl to parse tokens at runtime instead of compile time.

[untitaker]

fixed merge conflicts with maud 0.26: https://github.com/untitaker/maud/pull/new/hotreload-prototype-v2

it works perfectly for me as-is. just swap maud::html! with maud::html_hotreload! as you said. spoke too soon 😅 a few templates are not compatible with this runtime, but by and large it seems to work.

ideally there'd be a replacement for cargo watch -x run that works with this, but i'm content manually restarting my app when the code actually has to be recompiled, for now