Use CSS Vars to allow direct passthrough of tailwind variables

[The-Code-Monkey]

This is a suggestion on how to handle #36 as it sounds pretty interesting.

The way i was thinking of it was to enable the use of something like

div:scope {
  --padding: 0;
  padding: var(--padding);

 &[data-padding="--spacing-"] {}

which the parser would see this as

type BazProps = {
  children?: ReactNode,
  padding?: string,
} & JSX.IntrinsicElements['p']

export function Baz({ children, padding, ...props }: BazProps) {
  return (
    <p {...props} className="baz" style={{ "--padding": `var(--spacing-${padding})` }>
      {children}
    </p>
  )
}

I know its not the prettiest solution but it could work in terms of how simple it is, or maybe we could even remove the need for the &[data-padding] somehow and resolve this value from the --padding var directly e.g.

div:scope {
  --padding: var(--spacing-0); <-  default value
  padding: var(--padding);

this way we could infer that for padding prop to grab the first half of the assigned ts variable and then concat the prop onto the end.

[The-Code-Monkey]

I would be happy to do this solution if this is something you want to implement, either now or in the future.

[alamenai]

Hi @The-Code-Monkey ,

Thank you for the suggestions , but I guess it will add more complexity to the syntax.

[The-Code-Monkey]

It depends on which option you look at the second one is not too much syntax and follows a very similar format to how tailwind themselves do stuff.

the first one option is a little more complex but again not too complex its less complex than what im currently doing in my component lib thats using mist.

https://github.com/The-Code-Monkey/MistKit/blob/master/src/primals/flex/index.mist.css

it would make something like this so much cleaner and extendable for custom tailwind values.

as all i would have would be

  @scope (.flex) {
    div:scope {
      --direction: var(--flex-column);
      --justify: var(--justify-start);
      --items: var(--items-start);
      --content: var(--content-start);
      --gap: var(--gap-0);

     display: flex;
     gap: var(--gap);
     flex-direction: var(--direction);
     justify-content: var(--justify);
     align-items: var(--items);
     align-content: var(--content);
  }
}

This is much cleaner than current solution and more dynamic.

[alamenai]

Wow, Yep I liked it.

[The-Code-Monkey]

Wow, Yep I liked it.

Just have to get @typicode on side now ha ha

[typicode]

I've been thinking about CSS variables as well :)
For values that aren't enums (number, percent, color, ...)

So yes, MistCSS should support them. I'd like to a simple way to ignore computed CSS var or distinguish between "public"/"private".

For example:

input[type="checkbox"] {
  width: 80px;
  height: 80px;
  --i: 0;
  --hue: calc(var(--i) * 50 + 100);
  accent-color: hsl(var(--hue), 50%, 50%);
}

<div style="text-align: center">
  <input type="checkbox" checked style="--i: 0"/>
  <input type="checkbox" checked style="--i: 1"/>
  <input type="checkbox" checked style="--i: 2"/>
  <input type="checkbox" checked style="--i: 3"/>
</div>

I'd like the generated component to expose i as a prop but not hue.

[The-Code-Monkey]

Yeah I like that idea of how certain values are exposed and others aren't.

I think exposed values should be strings, numbers, CSS vars like my example above but yeah things like calc wouldn't be exposed

[The-Code-Monkey]

I'm currently working on a basic implementation for variables currently it will be finished off tomorrow morning and I'll submit it for review

[The-Code-Monkey]

I have an implementation written @alamenai typicode is working on refactoring so in the meantime i published my own so i can continue dev, don't recommend using it though as it will be removed once typicode is done with their refactor. And it is also will be buggy as i will test stuff in it.

https://github.com/The-Code-Monkey/mistcss/tree/v-andy

you can see it in action here

https://github.com/The-Code-Monkey/MistKit

[typicode]

An alternative to this, that can work with the current CSS variable implementation, could be to use the Tailwind variables in JS.

For example:

<Button color={colors.500} padding={spacing[8]}/>

https://github.com/tailwindlabs/tailwindcss/blob/master/stubs/config.full.js

This would have the benefit of having TS check that the keys used are valid.

// Error from TS
<Button color={colors.54321} padding={spacing.xl}/>

I haven't done research into exactly how this this can imported.

Edit:

Getting Tailwind variables is possible this way:

const defaultTheme = require('tailwindcss/defaultTheme')

[The-Code-Monkey]

Yeah this is what I would like to support maybe via a specific tailwind renderer. E.g. react tailwind.

But I would personally say for things like padding should be just 8 not spacing.8 as we should be able to infer the tailwind schema it belongs to. I'll have a look at supporting something next week

[typicode]

I see. I understand it could be easier but I think it could be possible with the existing code.

If you wrap Mist components in a function that would convert padding={8} to padding={theme.spaces.8} (and other properties) before passing it to Mist component, that could work.