module Sass::Script::Functions

def hsla(hue, saturation, lightness, alpha)

Raises:
  • (ArgumentError) - if `saturation`, `lightness`, or `alpha` are out of bounds

Other tags:
    See: #hsl -

Returns:
  • (Color) - The resulting color

Parameters:
  • alpha (Number) -- The opacity of the color.
  • lightness (Number) -- The lightness of the color.
  • saturation (Number) -- The saturation of the color.
  • hue (Number) -- The hue of the color. 
def hsla(hue, saturation, lightness, alpha)
  assert_type hue, :Number
  assert_type saturation, :Number
  assert_type lightness, :Number
  assert_type alpha, :Number
  unless (0..1).include?(alpha.value)
    raise ArgumentError.new("Alpha channel #{alpha.value} must be between 0 and 1")
  end
  original_s = saturation
  original_l = lightness
  # This algorithm is from http://www.w3.org/TR/css3-color#hsl-color
  h, s, l = [hue, saturation, lightness].map { |a| a.value }
  raise ArgumentError.new("Saturation #{s} must be between 0% and 100%") unless (0..100).include?(s)
  raise ArgumentError.new("Lightness #{l} must be between 0% and 100%") unless (0..100).include?(l)
  Color.new(:hue => h, :saturation => s, :lightness => l, :alpha => alpha.value)
end