Astro style css string

[JonathonRP]

Body

Summary

[vite-id]?[framework]&type=style&[astro:'index=0&']lang.css&inline - gets style css/scss string
it would be useful to have this working, currently get an error about syntax from ast parser.
also allowing this enables css retrieval for astro, svelte, ect... for container api.

svelte does this for their own styles - sveltekit

Background & Motivation

#462, #916, #533
I have been having an use with accessing css to render my component correctly and other users have expressed interest in being able to access the styles and scripts of rendered astro component with slots.

Goals

• fix error of ast parser
• concise place with info to access css or js of assets processed by vite.
• allow users access to css or js form container api rendered astro component.

Example

const { html, css, js } = astro_container.render(Component)

[JonathonRP]

@ematipico

[dwighthouse]

Such a feature would be very useful, though there should also be a corresponding way to transfer the component-generated css and/or js into whatever mechanism Astro is using to bundle css and js into the final page output under normal rendering conditions (without the container API).

[jarrp001]

Agreed. The render process is basically what I think is being asked for here, specifically around the styles and scripts. However, also having a way to access the unprocessed styles and scripts could be useful for things like preview in a visual UI tool.

[JonathonRP]

My current understanding is Astro uses vite for the preprocessing of styles and scripts. I haven't tested or tried to build access but from dev I get an error from my styles...

[dwighthouse]

Yes, I'm almost certain it's Vite.

@jarrp001 I want to make clear that there are several use cases here:

1. Render component and discard the css/js.
2. Render component and inject the css/js into regular render process (which may be another renderer calling this renderer).
3. Render component and manage the export of css/js yourself outside of the regular render process (export to file or something).

In both 2 and 3, you would have the opportunity to make manual changes to the css/js prior to sending it along to the final destination.

[JonathonRP]

Gotcha, yeah that would be good to have as part of the proposal. I was just trying to collect some useful information to get css and js exports working because currently it only renders html and sveltekit has html and head exports from components and it hands off to vite for processing too which is how it handles getting the styles from my understanding but I could be wrong.

[jarrp001]

I have tried using Card.astro?astro&type=style&index=0 inside of a Vite plugin. With the plugin returning the meta data when using something like import(Card.astro?metadata). Unfortunately Vite is stripping out the code.

While getting access to the scripts and CSS would be very useful for preview, I don't really like this solution for a final build. It would be the unprocessed scripts and CSS, from what I can tell.

So, in addition to something like what I am doing above, to access the unprocessed CSS/scripts, something like you propose would be great, something that returns the processed CSS/scripts. Only change I would make is to the names.

So:

const { content, styles, scripts } = astro_container.render(Component);

[JonathonRP]

I do like the rename, I could go either way with names only really care about gaining the functionality of getting style and scripts. My personal use needs the processed styles but it would be handy to have access to unprocessed styles. In my case I think with vite my styles could be grabbed with lang.scss but maybe your using css and don't want postcss processing, maybe that could be achieved by not supplying lang.

Currently I get an error getting my styles as mentioned above.