Sass Modifiers Mixin

modifiers.scss

// ----
// Sass (v3.4.21)
// Compass (v1.0.3)
// ----

// Sass modifiers mixin by Sarah Dayan
// Generate All Your Utility Classes with Sass Maps: frontstuff.io/generate-all-your-utility-classes-with-sass-maps
// http://frontstuff.io
// https://github.com/sarahdayan

$colors: (
  red: #ff3538,
  grey: (
    base: #404145,
    light: #c7c7cd
  ),
  yellow: (
    base: #ecaf2d
  ),
  green: (
    base: #5ad864
  )
);

$font-sizes: (
  small: 12px,
  medium: 14px,
  large: 16px,
  x-large: 18px,
  xx-large: 20px
);

@mixin modifiers($map, $attribute, $prefix: '-', $separator: '-', $base: 'base') {
  @each $key, $value in $map {
    &#{if($key != $base, #{$prefix}#{$key}, '')} {
      @if type-of($value) == 'map' {
        @include modifiers($value, $attribute, $separator);
      }
      @else {
        #{$attribute}: $value;
      }
    }
  }
}

.text {
  @include modifiers($colors, 'color', $separator: ':');
  @include modifiers($font-sizes, 'font-size', '--');
}

undefined

.text-red {
  color: #ff3538;
}
.text-grey {
  color: #404145;
}
.text-grey:light {
  color: #c7c7cd;
}
.text-yellow {
  color: #ecaf2d;
}
.text-green {
  color: #5ad864;
}
.text--small {
  font-size: 12px;
}
.text--medium {
  font-size: 14px;
}
.text--large {
  font-size: 16px;
}
.text--x-large {
  font-size: 18px;
}
.text--xx-large {
  font-size: 20px;
}

Why isn't separator used in the modifiers mixin?

@sarahdayan, this is awesome. Could you please explain how negative values (eg. -4px) can be supported? Is there a way to handle @media queries in the @mixin for handy breakpoint changes?

@sarahdayan Amazing gist, I've built something nice with it.

@raphaelobene check how I'm using this to generate negative margin. For media I think you can use some condition as I'm doing here in the case of default. Also you can try wrapping the the class with media queries and passing different sizes but I'm not sure if it will generate the css you want but you can try it.

/** Custom CSS Variables **/
:root {
  --ion-space-xs: 4px;
  --ion-space-sm: calc(var(--ion-space-xs) * 2);
  --ion-space-md: calc(var(--ion-space-xs) * 3);
  --ion-space: calc(var(--ion-space-xs) * 4);

  --ion-negative-space-xs: calc(var(--ion-space-xs) * -1);
  --ion-negative-space-sm: calc(var(--ion-space-md) * -1);
  --ion-negative-space-md: calc(var(--ion-space-md) * -1);
  --ion-negative-space: calc(var(--ion-space) * -1);
}

$spaces: (
  xs: var(--ion-space-xs),
  sm: var(--ion-space-sm),
  md: var(--ion-space-md)
);

$negative-spaces: (
  xs: var(--ion-negative-space-xs),
  sm: var(--ion-negative-space-sm),
  md: var(--ion-negative-space-md),
  default: var(--ion-negative-space)
);

@mixin class-variations($args, $attribute: 'padding', $prefix: '') {
  @each $key, $value in $args {
    @if $key == 'default' {
      &#{$prefix} {
        #{$attribute}: $value;
      }
    } @else {
      &#{$prefix}-#{$key} {
        #{$attribute}: $value;
      }
    }
  }
}

// Generate padding variations
.ion-padding {
  @include class-variations($args: $spaces);
  @include class-variations($args: $spaces, $attribute: 'padding-top', $prefix: '-top');
  @include class-variations($args: $spaces, $attribute: 'padding-left', $prefix: '-start');
  @include class-variations($args: $spaces, $attribute: 'padding-right', $prefix: '-end');
  @include class-variations($args: $spaces, $attribute: 'padding-bottom', $prefix: '-bottom');
}

// Generate margin variations
.ion-margin {
  @include class-variations($args: $spaces);
  @include class-variations($args: $spaces, $attribute: 'margin-top', $prefix: '-top');
  @include class-variations($args: $spaces, $attribute: 'margin-left', $prefix: '-start');
  @include class-variations($args: $spaces, $attribute: 'margin-right', $prefix: '-end');
  @include class-variations($args: $spaces, $attribute: 'margin-bottom', $prefix: '-bottom');
}

.ion-negative-margin {
  @include class-variations($args: $negative-spaces, $attribute: 'margin-top', $prefix: '-top');
  @include class-variations($args: $negative-spaces, $attribute: 'margin-left', $prefix: '-start');
  @include class-variations($args: $negative-spaces, $attribute: 'margin-right', $prefix: '-end');
  @include class-variations($args: $negative-spaces, $attribute: 'margin-bottom', $prefix: '-bottom');
}

Thanks for the article, very well explained!