SASS / SCSS mixin生成css网格类 - IE 11需要额外的20px间隙列

Question

我有以下SCSS mixin，它生成从.grid1到.grid12的CSS类：

$columns: 12;
@mixin repeat($character, $n) {
    $c: "";
    @for $i from 1 through $n {
        $c: $c + $character;
    }
    -ms-grid-columns: unquote($c);
}


// classes for defining number of equally sized (sub-)grid columns
@mixin grid-x {
    @for $i from 1 through $columns {
        .grid#{$i} {
            @include repeat(" 1fr", $i);
        }
    }
}

@include grid-x;

使用libsass生成的CSS类看起来像这样：

.grid1 {
  -ms-grid-columns:  1fr;
}

.grid2 {
  -ms-grid-columns:  1fr 1fr;
}

.grid3 {
  -ms-grid-columns:  1fr 1fr 1fr;
}
...

由于IE 11不支持grid-gap，我想在代中的列之间插入20px间隙列。

预期结果如下所示：

// nothing changed for .grid1
.grid1 {
  -ms-grid-columns:  1fr;
}

.grid2 {
  -ms-grid-columns:  1fr 20px 1fr;
}

.grid3 {
  -ms-grid-columns:  1fr 20px 1fr 20px 1fr;
}
...

只需在重复字符串中添加20px列会导致不必要的尾随20px：

@include repeat(" 1fr 20px", $i);

结果是

.grid1 {
  -ms-grid-columns:  1fr 20px;
}                        ^^^^

.grid2 {
  -ms-grid-columns:  1fr 20px 1fr 20px;
}^                                ^^^^

.grid3 {
  -ms-grid-columns:  1fr 20px 1fr 20px 1fr 20px;
}                                          ^^^^
...

有关如何使用SCSS mixins获得所需结果的任何想法？

为了便于测试，只需将mixins粘贴到sassmeister上即可。

Answer 1

你可以为差距包含另一个变量，并像这样做。

$columns: 12;
@mixin repeat($character, $gap, $n) {
    $c: "";
    @if ($n != 1) {
      @for $i from 1 through ($n - 1) {
          $c: $c+" "+$character+" "+$gap ;
      }
    }
    $c: $c+" "+$character ;
    -ms-grid-columns: unquote($c);
}


// classes for defining number of equally sized (sub-)grid columns
@mixin grid-x {
    @for $i from 1 through $columns  {
        .grid#{$i} {
            @include repeat("1fr","20px", $i);
        }
    }
}

@include grid-x;

如果您在间隙中指定并清空字符串，这也会为您提供初始结果：

Answer 2

我能够使用@if () { } @else { }自己解决它：

$columns: 12;
@mixin repeat($character, $n) {
    $c: "";
    @for $i from 1 through $n {
      @if ($n == 1 or $i == $n) {
        $c: $c + $character;
      } @else {
        $c: $c + $character + " 20px";
      }  
    }
    -ms-grid-columns: unquote($c);
}


// classes for defining number of equally sized (sub-)grid columns
@mixin grid-x {
    @for $i from 1 through $columns {
        .grid#{$i} {
            @include repeat(" 1fr", $i);
        }
    }
}

@include grid-x;