_functions.scss

// Strip Invalid Character. Use to create a valid placeholder name
// -----------------------------------------------------------------------------
// @param  String $string
// @return String
// -----------------------------------------------------------------------------

@function sf-strip-invalid-char( $string ) {
  $index-dot : 0;
  $new-string: "";
  $string: "#{$string}"; // forcing to make it a string

  @for $i from 1 through str-length($string) {
    $character: str-slice($string, $i, $i);

   // create a new string without the illegal char.
    @if $character == "." {
        $index-dot: $i;
    } @else if $character == "%" {
        $index-dot: $i;
    } @else if $character == ":" {
        $index-dot: $i;
    } @else {
      $new-string: $new-string + $character;
    }
  }
  // return new string
  @if $index-dot {
     @return $new-string;
  } @else {
     @warn "String: #{$string} doesn't have any illegal character(s).";
  }
}