为什么 (xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px) 在 Sassmeister 中不是有效的 CSS 值？

Question

我正在尝试在https://www.sassmeister.com/上处理以下 Sass，但出现错误：

(xs: 0, sm: 576px, md: 768px, lg: 992px, xl: 1200px) 不是有效的 CSS 值。

$grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
) !default;
$utilities: () !default;

$utilities: map-merge(
  (
    "align": (
      property: vertical-align,
      class: align,
      values: baseline top middle bottom text-bottom text-top
    ),
    "float": (
      responsive: true,
      property: float,
      values: left right none
    )
), $utilities);


// Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
// Makes the @content apply to the given breakpoint and wider.
@mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
  $min: breakpoint-min($name, $breakpoints);
  @if $min {
    @media (min-width: $min) {
      @content;
    }
  } @else {
    @content;
  }
}


// Loop over each breakpoint
@each $breakpoint in map-keys($grid-breakpoints) {

  // Generate media query if needed
  @include media-breakpoint-up($breakpoint) {
    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);

    // Loop over each utility property
    @each $key, $utility in $utilities {
      // The utility can be disabled with `false`, thus check if the utility is a map first
      // Only proceed if responsive media queries are enabled or if it's the base media query
      @if type-of($utility) == "map" and (map-get($utility, responsive) or $infix == "") {
        @include generate-utility($utility, $infix);
      }
    }
  }
}


// Print utilities
@media print {
  @each $key, $utility in $utilities {
    // The utility can be disabled with `false`, thus check if the utility is a map first
    // Then check if the utility needs print styles
    @if type-of($utility) == "map" and map-get($utility, print) == true {
      @include generate-utility($utility, "-print");
    }
  }
}

知道这里有什么问题吗？

Answer 1

您正在调用一系列未定义的函数： breakpoint-infix() 、 breakpoint-min()以及 mixin generate-utility() ......它们在哪里？

它们是你必须包含的Bootstrap函数和 mixin（你在你的项目中使用 Bootstrap 吗？也许你可以更简单地导入它，而不仅仅是 2 个文件或函数）。

你可以在这里找到这两个函数： https : //github.com/twbs/bootstrap/blob/master/scss/mixins/_breakpoints.scss

和这里的混合： https : //github.com/twbs/bootstrap/blob/master/scss/mixins/_utilities.scss

包含它们后，您的代码运行良好：

/*https://github.com/twbs/bootstrap-rubygem/blob/master/assets/stylesheets/bootstrap/mixins/_breakpoints.scss*/


@function breakpoint-min($name, $breakpoints: $grid-breakpoints) {
  $min: map-get($breakpoints, $name);
  @return if($min != 0, $min, null);
}

@function breakpoint-infix($name, $breakpoints: $grid-breakpoints) {
  @return if(breakpoint-min($name, $breakpoints) == null, "", "-#{$name}");
}

/*https://github.com/twbs/bootstrap/blob/master/scss/mixins/_utilities.scss*/

@mixin generate-utility($utility, $infix) {
  $values: map-get($utility, values);

  // If the values are a list or string, convert it into a map
  @if type-of($values) == "string" or type-of(nth($values, 1)) != "list" {
    $values: zip($values, $values);
  }

  @each $key, $value in $values {
    $properties: map-get($utility, property);

    // Multiple properties are possible, for example with vertical or horizontal margins or paddings
    @if type-of($properties) == "string" {
      $properties: append((), $properties);
    }

    // Use custom class if present
    $property-class: if(map-has-key($utility, class), map-get($utility, class), nth($properties, 1));
    $property-class: if($property-class == null, "", $property-class);

    $infix: if($property-class == "" and str-slice($infix, 1, 1) == "-", str-slice($infix, 2), $infix);

    // Don't prefix if value key is null (eg. with shadow class)
    $property-class-modifier: if($key, if($property-class == "" and $infix == "", "", "-") + $key, "");

    .#{$property-class + $infix + $property-class-modifier} {
      @each $property in $properties {
        // stylelint-disable-next-line declaration-no-important
        #{$property}: $value !important;
      }
    }
  }
}

/*your code */



$grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
);
$utilities: () !default;

$utilities: map-merge(
  (
    "align": (
      property: vertical-align,
      class: align,
      values: baseline top middle bottom text-bottom text-top
    ),
    "float": (
      responsive: true,
      property: float,
      values: left right none
    )
), $utilities);


// Media of at least the minimum breakpoint width. No query for the smallest breakpoint.
// Makes the @content apply to the given breakpoint and wider.
@mixin media-breakpoint-up($name, $breakpoints: $grid-breakpoints) {
  $min: breakpoint-min($name, $breakpoints);
  @if $min {
    @media (min-width: $min) {
      @content;
    }
  } @else {
    @content;
  }
}


// Loop over each breakpoint
@each $breakpoint in map-keys($grid-breakpoints) {

  // Generate media query if needed
  @include media-breakpoint-up($breakpoint) {
    $infix: breakpoint-infix($breakpoint, $grid-breakpoints);

    // Loop over each utility property
    @each $key, $utility in $utilities {
      // The utility can be disabled with `false`, thus check if the utility is a map first
      // Only proceed if responsive media queries are enabled or if it's the base media query
      @if type-of($utility) == "map" and (map-get($utility, responsive) or $infix == "") {
        @include generate-utility($utility, $infix);
      }
    }
  }
}


// Print utilities
@media print {
  @each $key, $utility in $utilities {
    // The utility can be disabled with `false`, thus check if the utility is a map first
    // Then check if the utility needs print styles
    @if type-of($utility) == "map" and map-get($utility, print) == true {
      @include generate-utility($utility, "-print");
    }
  }
}

这是输出：

.align-baseline {
  vertical-align: baseline !important;
}

.align-top {
  vertical-align: top !important;
}

.align-middle {
  vertical-align: middle !important;
}

.align-bottom {
  vertical-align: bottom !important;
}

.align-text-bottom {
  vertical-align: text-bottom !important;
}

.align-text-top {
  vertical-align: text-top !important;
}

.float-left {
  float: left !important;
}

.float-right {
  float: right !important;
}

.float-none {
  float: none !important;
}

@media (min-width: 576px) {
  .float-sm-left {
    float: left !important;
  }

  .float-sm-right {
    float: right !important;
  }

  .float-sm-none {
    float: none !important;
  }
}
@media (min-width: 768px) {
  .float-md-left {
    float: left !important;
  }

  .float-md-right {
    float: right !important;
  }

  .float-md-none {
    float: none !important;
  }
}
@media (min-width: 992px) {
  .float-lg-left {
    float: left !important;
  }

  .float-lg-right {
    float: right !important;
  }

  .float-lg-none {
    float: none !important;
  }
}
@media (min-width: 1200px) {
  .float-xl-left {
    float: left !important;
  }

  .float-xl-right {
    float: right !important;
  }

  .float-xl-none {
    float: none !important;
  }
}

Answer 2

您可以尝试使用

 $grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
);

$container-max-widths: (
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
);

请包括引导程序