Sass IE filters helper.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.18)
// ----

//
// Sass IE filters helper.
//


// Join `$list` into a string.
// -----------------------------------------------------------------------------
// @param [list] $list
// @param [string] $glue
// -----------------------------------------------------------------------------
// @return [string]

@function _join($list, $glue: "") {
  $result: "";
  $length: length($list);

  @if $length < 1 {
    @return $result;
  }

  @for $i from 1 through $length {
    $result: $result
             + nth($list, $i)
             + if($i != $length, $glue, "");
  }

  @return $result;
}


// Capitalize string
// --------------------------------------------------------------------------------
// @param [string] $string
// --------------------------------------------------------------------------------
// @return [string]

@function capitalize($string) {
  @return to-upper-case(str-slice($string, 1, 1)) + str-slice($string, 2);
}


// IE filter formatting helper
// -----------------------------------------------------------------------------
// @param [filter] $string: filter name
// @param [arglist] $args: filter properties
// -----------------------------------------------------------------------------
// @dependencies `_join()`, `capitalize()`
// -----------------------------------------------------------------------------
// @return [string]

@function _ie-filter(
  $filter,
  $args...
) {
  $properties: ();
  $parts: (
    "progid:DXImageTransform.Microsoft.",
    "#{capitalize($filter)}",
    "(",
    "properties",
    ")"
  );

  @each $key, $value in keywords($args) {
    @if type-of($value) == color {
      $value: "'#{ie-hex-str($value)}'";
    }
    $properties: append($properties, "#{$key}=#{$value}");
  }

  $parts: set-nth(
            $parts,
            index($parts, "properties"),
            _join($properties, ", ")
          );

  @return _join($parts);
}


@mixin ie-filter($filter, $args...) {
  -ms-filter: quote(_ie-filter($filter, $args...));  // IE 8+
  filter: unquote(_ie-filter($filter, $args...));    // IE < 8
}


// Test
sass {
  @include ie-filter(Light);
  @include ie-filter(Blur, $pixelRadius: 5);
  @include ie-filter(DropShadow, $OffX: 5px, $OffY: 5px, $Color: rgba(0, 0, 0, .5));
}

SassMeister-output.css

sass {
  -ms-filter: "progid:DXImageTransform.Microsoft.Light()";
  filter: progid:DXImageTransform.Microsoft.Light();
  -ms-filter: "progid:DXImageTransform.Microsoft.Blur(pixelRadius=5)";
  filter: progid:DXImageTransform.Microsoft.Blur(pixelRadius=5);
  -ms-filter: "progid:DXImageTransform.Microsoft.DropShadow(OffX=5px, OffY=5px, Color='#80000000')";
  filter: progid:DXImageTransform.Microsoft.DropShadow(OffX=5px, OffY=5px, Color='#80000000');
}