Not able to update variable in custom css

[rohitspawar2911]

Hello
I have used this theme switcher and it's working. But the issue is when I have to write a custom CSS class and want to use Bootstrap variable its not reflecting.
ex:
In custom.scss
body{
background: $primary;
}

dark.scss
$primary: #000000;

light.scss
$primary: #ff0000;

CSS after compilation:
For Both Theme:
custom.css
body{
background:#007bff; // Bootstrap default Variable
}

If Dark Theme
bootstrap.css
body{
background:#00000;
}

If light theme:
body{
background:#ff0000;
}

Can you please help me to solve this issue?
Thanks

[jfhr]

Yea, this is because of how angular creates stylesheets. The code in custom.scss is compiled once, using the variable values that are set for that file at build time. In your case, custom.scss uses the bootstrap default variables.

One workaround is to use CSS variables instead of bootstrap variables. CSS variables can change at runtime when you select a different theme. I've created a pull request #8 to demonstrate how it could work, but the short version is:

In custom.scss:

body{
  // use the CSS variable --primary
  background: var(--primary);
}

In dark.scss:

$primary: #000000;
// Create a CSS variable --primary with the same value as the bootstrap variable $primary
* {
  --primary: #{$primary};
}

In light.scss:

$primary: #ff0000;
// Create a CSS variable --primary with the same value as the bootstrap variable $primary
* {
  --primary: #{$primary};
}

CSS variables are supported in all modern browsers.

Hope this helps!