Generate CSS classes dynamically based on variables - SCSS

Question

I have color variables (example):


// _colors.scss
:root, * {
  --color-primary-50: 1,1,1;
  --color-primary-100: 2,2,2;
  --color-primary-200: 3,3,3;
}

And I want to generate classes based on the variables, for example:


// _background.scss
.bg-primary-50 {
  background: rgb(var(--color-primary-50));
}

.bg-primary-100 {
  background: rgb(var(--color-primary-100));
}

.bg-primary-200 {
  background: rgb(var(--color-primary-200));
}

I want to simplify my future modifications if I need to change or add new colors and dynamically populate my _background file with classes based on _colors variables.

It seems like a lot of monotonic work. Is there any way to get this result? Perhaps I should change my file structure?

Kunal Tanwar · Accepted Answer · 2022-05-15T19:56:29.263

use @each loop. Instead of creating the vars in :root add those in a single var (see below example)

$colors : (
  "primary-50":  "1,1,1",
  "primary-100": "2,2,2",
  "primary-200": "3,3,3",
);

@each $color, $value in $colors {
    .bg-#{$color} {
        background-color: rgb($value);
    }
}

the above code compiled into

.bg-primary-50 {
  background-color: #010101;
}
.bg-primary-100 {
  background-color: #020202;
}
.bg-primary-200 {
  background-color: #030303;
}

And for CSS --variables

:root {
    @each $color, $value in $colors {
        --color-#{$color}: rgb($value);
    }
}

and you have CSS Variables

:root {
  --color-primary-50: #010101;
  --color-primary-100: #020202;
  --color-primary-200: #030303;
}

Like you mentioned in your comment "will this solution work for the light and dark modes?" for that you can do something like this

html[data-color-mode="dark"] {
  $dark-mode-colors: (
    "primary-color-50": "0, 0, 0",
    "primary-color-100": "1, 1, 1",
    "primary-color-200": "2, 2, 2",
  )

  @each $color, $value in $colors {
    .bg-#{$color} {
        background-color: $value;
    }
  }
}

// change your color scheme as you prefer method will remain the same
html[data-color-mode="light"] {
  $light-mode-colors: (
    "primary-color-50": "0, 0, 0",
    "primary-color-100": "1, 1, 1",
    "primary-color-200": "2, 2, 2",
  )

  @each $color, $value in $colors {
    .bg-#{$color} {
        background-color: $value;
    }
  }
}

Thank you for the answer! Question, will this solution work for the light and dark modes? — Anton S., May 15 '22 at 17:59
As far as I understand this solution, we need to create SCSS variables first, then get our CSS variables. Am I right? Sorry, I just want to make sure that I understand how it works :) — Anton S., May 15 '22 at 18:07
yes first you need to create `scss` variables and then you will get your css variables then you can use those `css` variables like you mentioned in your question. — Kunal Tanwar, May 15 '22 at 18:08
That's exactly what I needed. I use hex values for colours though, and needed to use `--color-#{$color}: #{$value}` for my css variables to work. `$value`is not enough and the #{} is required here (it is not necessary for the classes) — Shautieh, May 04 '23 at 21:26

Generate CSS classes dynamically based on variables - SCSS

1 Answers1