module Sass::Script::Functions
Methods in this module are accessible from the SassScript context. For example, you can write
$color: hsl(120deg, 100%, 50%)
and it will call {Sass::Script::Functions#hsl}.
The following functions are provided:
*Note: These functions are described in more detail below.*
## RGB Functions
{#rgb rgb($red, $green, $blue)} : Creates a {Color} from red, green, and blue values.
{#rgba rgba($red, $green, $blue, $alpha)} : Creates a {Color} from red, green, blue, and alpha values.
{#red red($color)} : Gets the red component of a color.
{#green green($color)} : Gets the green component of a color.
{#blue blue($color)} : Gets the blue component of a color.
{#mix mix($color-1, $color-2, [$weight])} : Mixes two colors together.
## HSL Functions
{#hsl hsl($hue, $saturation, $lightness)} : Creates a {Color} from hue, saturation, and lightness values.
{#hsla hsla($hue, $saturation, $lightness, $alpha)} : Creates a {Color} from hue, saturation, lightness, and alpha
values.
{#hue hue($color)} : Gets the hue component of a color.
{#saturation saturation($color)} : Gets the saturation component of a color.
{#lightness lightness($color)} : Gets the lightness component of a color.
{#adjust_hue adjust-hue($color, $degrees)} : Changes the hue of a color.
{#lighten lighten($color, $amount)} : Makes a color lighter.
{#darken darken($color, $amount)} : Makes a color darker.
{#saturate saturate($color, $amount)} : Makes a color more saturated.
{#desaturate desaturate($color, $amount)} : Makes a color less saturated.
{#grayscale grayscale($color)} : Converts a color to grayscale.
{#complement complement($color)} : Returns the complement of a color.
{#invert invert($color)} : Returns the inverse of a color.
## Opacity Functions
{#alpha alpha($color)} / {#opacity opacity($color)} : Gets the alpha component (opacity) of a color.
{#rgba rgba($color, $alpha)} : Changes the alpha component for a color.
{#opacify opacify($color, $amount)} / {#fade_in fade-in($color, $amount)} : Makes a color more opaque.
{#transparentize transparentize($color, $amount)} / {#fade_out fade-out($color, $amount)} : Makes a color more transparent.
{#adjust_color adjust-color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])} : Increases or decreases one or more components of a color.
{#scale_color scale-color($color, [$red], [$green], [$blue], [$saturation], [$lightness], [$alpha])} : Fluidly scales one or more properties of a color.
{#change_color change-color($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha])} : Changes one or more properties of a color.
{#ie_hex_str ie-hex-str($color)} : Converts a color into the format understood by IE filters.
{#unquote unquote($string)} : Removes quotes from a string.
{#quote quote($string)} : Adds quotes to a string.
{#percentage percentage($value)} : Converts a unitless number to a percentage.
{#round round($value)} : Rounds a number to the nearest whole number.
{#ceil ceil($value)} : Rounds a number up to the next whole number.
{#floor floor($value)} : Rounds a number down to the previous whole number.
{#abs abs($value)} : Returns the absolute value of a number.
{#min min($numbers…)} : Finds the minimum of several numbers.
{#max max($numbers…)} : Finds the maximum of several numbers.
## List
Functions
{#list-functions}
{#length length($list)} : Returns the length of a list.
{#nth nth($list, $n)} : Returns a specific item in a list.
{#join join($list1, $list2, [$separator])} : Joins together two lists into one.
{#append append($list1, $val, [$separator])} : Appends a single value onto the end of a list.
{#zip zip($lists…)} : Combines several lists into a single multidimensional list.
{#index index($list, $value)} : Returns the position of a value within a list.
## Introspection Functions
{#type_of type-of($value)} : Returns the type of a value.
{#unit unit($number)} : Returns the unit(s) associated with a number.
{#unitless unitless($number)} : Returns whether a number has units.
{#comparable comparable($number-1, $number-2)} : Returns whether two numbers can be added, subtracted, or compared.
## Miscellaneous Functions
{#if if($condition, $if-true, $if-false)} : Returns one of two values, depending on whether or not ‘$condition` is
true.
## Adding Custom Functions
New Sass
functions can be added by adding Ruby methods to this module. For example:
module Sass::Script::Functions def reverse(string) assert_type string, :String Sass::Script::String.new(string.value.reverse) end declare :reverse, :args => [:string] end
Calling {declare} tells Sass
the argument names for your function. If omitted, the function will still work, but will not be able to accept keyword arguments. {declare} can also allow your function to take arbitrary keyword arguments.
There are a few things to keep in mind when modifying this module. First of all, the arguments passed are {Sass::Script::Literal} objects. Literal
objects are also expected to be returned. This means that Ruby values must be unwrapped and wrapped.
Most Literal
objects support the {Sass::Script::Literal#value value} accessor for getting their Ruby values. Color
objects, though, must be accessed using {Sass::Script::Color#rgb rgb}, {Sass::Script::Color#red red}, {Sass::Script::Color#blue green}, or {Sass::Script::Color#blue blue}.
Second, making Ruby functions accessible from Sass
introduces the temptation to do things like database access within stylesheets. This is generally a bad idea; since Sass
files are by default only compiled once, dynamic code is not a great fit.
If you really, really need to compile Sass
on each request, first make sure you have adequate caching set up. Then you can use {Sass::Engine} to render the code, using the {file:SASS_REFERENCE.md#custom-option ‘options` parameter} to pass in data that {EvaluationContext#options can be accessed} from your Sass
functions.
Within one of the functions in this module, methods of {EvaluationContext} can be used.
### Caveats
When creating new {Literal} objects within functions, be aware that it’s not safe to call {Literal#to_s to_s} (or other methods that use the string representation) on those objects without first setting {Node#options= the options attribute}.
Constants
- Signature
A class representing a
Sass
function signature.@attr args [Array<Symbol>] The names of the arguments to the function. @attr var_args [Boolean] Whether the function takes a variable number of arguments. @attr var_kwargs [Boolean] Whether the function takes an arbitrary set of keyword arguments.
Public Class Methods
Declare a Sass
signature for a Ruby-defined function. This includes the names of the arguments, whether the function takes a variable number of arguments, and whether the function takes an arbitrary set of keyword arguments.
It’s not necessary to declare a signature for a function. However, without a signature it won’t support keyword arguments.
A single function can have multiple signatures declared as long as each one takes a different number of arguments. It’s also possible to declare multiple signatures that all take the same number of arguments, but none of them but the first will be used unless the user uses keyword arguments.
@example
declare :rgba, [:hex, :alpha] declare :rgba, [:red, :green, :blue, :alpha] declare :accepts_anything, [], :var_args => true, :var_kwargs => true declare :some_func, [:foo, :bar, :baz], :var_kwargs => true
@param method_name [Symbol] The name of the method
whose signature is being declared.
@param args [Array<Symbol>] The names of the arguments for the function signature. @option options :var_args [Boolean] (false)
Whether the function accepts a variable number of (unnamed) arguments in addition to the named arguments.
@option options :var_kwargs [Boolean] (false)
Whether the function accepts other keyword arguments in addition to those in `:args`. If this is true, the Ruby function will be passed a hash from strings to {Sass::Script::Literal}s as the last argument. In addition, if this is true and `:var_args` is not, Sass will ensure that the last argument passed is a hash.
# File lib/sass/script/functions.rb, line 267 def self.declare(method_name, args, options = {}) @signatures[method_name] ||= [] @signatures[method_name] << Signature.new( args.map {|s| s.to_s}, options[:var_args], options[:var_kwargs]) end
Determine the correct signature for the number of arguments passed in for a given function. If no signatures match, the first signature is returned for error messaging.
@param method_name [Symbol] The name of the Ruby function to be called. @param arg_arity [Number] The number of unnamed arguments the function was passed. @param kwarg_arity [Number] The number of keyword arguments the function was passed.
@return [{Symbol => Object}, nil]
The signature options for the matching signature, or nil if no signatures are declared for this function. See {declare}.
# File lib/sass/script/functions.rb, line 286 def self.signature(method_name, arg_arity, kwarg_arity) return unless @signatures[method_name] @signatures[method_name].each do |signature| return signature if signature.args.size == arg_arity + kwarg_arity next unless signature.args.size < arg_arity + kwarg_arity # We have enough args. # Now we need to figure out which args are varargs # and if the signature allows them. t_arg_arity, t_kwarg_arity = arg_arity, kwarg_arity if signature.args.size > t_arg_arity # we transfer some kwargs arity to args arity # if it does not have enough args -- assuming the names will work out. t_kwarg_arity -= (signature.args.size - t_arg_arity) t_arg_arity = signature.args.size end if ( t_arg_arity == signature.args.size || t_arg_arity > signature.args.size && signature.var_args ) && (t_kwarg_arity == 0 || t_kwarg_arity > 0 && signature.var_kwargs) return signature end end @signatures[method_name].first end
Private Class Methods
# File lib/sass/script/functions.rb, line 356 def include(*args) r = super # We have to re-include ourselves into EvaluationContext to work around # an icky Ruby restriction. EvaluationContext.send :include, self r end
Public Instance Methods
Returns the absolute value of a number.
@example
abs(10px) => 10px abs(-10px) => 10px
@overload abs($value) @param $value [Number] @return [Number] @raise [ArgumentError] if ‘$value` isn’t a number
# File lib/sass/script/functions.rb, line 1260 def abs(value) numeric_transformation(value) {|n| n.abs} end
Increases or decreases one or more properties of a color. This can change the red, green, blue, hue, saturation, value, and alpha properties. The properties are specified as keyword arguments, and are added to or subtracted from the color’s current value for that property.
All properties are optional. You can’t specify both RGB properties (‘$red`, `$green`, `$blue`) and HSL properties (`$hue`, `$saturation`, `$value`) at the same time.
@example
adjust-color(#102030, $blue: 5) => #102035 adjust-color(#102030, $red: -5, $blue: 5) => #0b2035 adjust-color(hsl(25, 100%, 80%), $lightness: -30%, $alpha: -0.4) => hsla(25, 100%, 50%, 0.6)
@overload adjust_color
($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha]) @param $color [Color] @param $red [Number] The adjustment to make on the red component, between
-255 and 255 inclusive
@param $green [Number] The adjustment to make on the green component,
between -255 and 255 inclusive
@param $blue [Number] The adjustment to make on the blue component, between
-255 and 255 inclusive
@param $hue [Number] The adjustment to make on the hue component, in
degrees
@param $saturation [Number] The adjustment to make on the saturation
component, between `-100%` and `100%` inclusive
@param $lightness [Number] The adjustment to make on the lightness
component, between `-100%` and `100%` inclusive
@param $alpha [Number] The adjustment to make on the alpha component,
between -1 and 1 inclusive
@return [Color] @raise [ArgumentError] if any parameter is the wrong type or out-of
bounds, or if RGB properties and HSL properties are adjusted at the same time
# File lib/sass/script/functions.rb, line 828 def adjust_color(color, kwargs) assert_type color, :Color, :color with = Sass::Util.map_hash({ "red" => [-255..255, ""], "green" => [-255..255, ""], "blue" => [-255..255, ""], "hue" => nil, "saturation" => [-100..100, "%"], "lightness" => [-100..100, "%"], "alpha" => [-1..1, ""] }) do |name, (range, units)| next unless val = kwargs.delete(name) assert_type val, :Number, name Sass::Util.check_range("$#{name}: Amount", range, val, units) if range adjusted = color.send(name) + val.value adjusted = [0, Sass::Util.restrict(adjusted, range)].max if range [name.to_sym, adjusted] end unless kwargs.empty? name, val = kwargs.to_a.first raise ArgumentError.new("Unknown argument $#{name} (#{val})") end color.with(with) end
Changes the hue of a color. Takes a color and a number of degrees (usually between ‘-360deg` and `360deg`), and returns a color with the hue rotated along the color wheel by that amount.
@example
adjust-hue(hsl(120, 30%, 90%), 60deg) => hsl(180, 30%, 90%) adjust-hue(hsl(120, 30%, 90%), 060deg) => hsl(60, 30%, 90%) adjust-hue(#811, 45deg) => #886a11
@overload adjust_hue
($color, $degrees) @param $color [Color] @param $degrees [Number] The number of degrees to rotate the hue @return [Color] @raise [ArgumentError] if either parameter is the wrong type
# File lib/sass/script/functions.rb, line 771 def adjust_hue(color, degrees) assert_type color, :Color, :color assert_type degrees, :Number, :degrees color.with(:hue => color.hue + degrees.value) end
Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified.
This function also supports the proprietary Microsoft ‘alpha(opacity=20)` syntax as a special case.
@overload alpha($color) @param $color [Color] @return [Number] The alpha component, between 0 and 1 @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 604 def alpha(*args) if args.all? do |a| a.is_a?(Sass::Script::String) && a.type == :identifier && a.value =~ /^[a-zA-Z]+\s*=/ end # Support the proprietary MS alpha() function return Sass::Script::String.new("alpha(#{args.map {|a| a.to_s}.join(", ")})") end raise ArgumentError.new("wrong number of arguments (#{args.size} for 1)") if args.size != 1 assert_type args.first, :Color, :color Sass::Script::Number.new(args.first.alpha) end
Appends a single value onto the end of a list.
Unless the ‘$separator` argument is passed, if the list had only one item, the resulting list will be space-separated.
@example
append(10px 20px, 30px) => 10px 20px 30px append((blue, red), green) => blue, red, green append(10px 20px, 30px 40px) => 10px 20px (30px 40px) append(10px, 20px, comma) => 10px, 20px append((blue, red), green, space) => blue red green
@overload append($list, $val, $separator: auto) @param $list [Literal] @param $val [Literal] @param $separator [String] The list separator to use. If this is ‘comma`
or `space`, that separator will be used. If this is `auto` (the default), the separator is determined as explained above.
@return [List]
# File lib/sass/script/functions.rb, line 1398 def append(list, val, separator = Sass::Script::String.new("auto")) assert_type separator, :String, :separator unless %w[auto space comma].include?(separator.value) raise ArgumentError.new("Separator name must be space, comma, or auto") end sep = list.separator if list.is_a?(Sass::Script::List) Sass::Script::List.new( list.to_a + [val], if separator.value == 'auto' sep || :space else separator.value.to_sym end) end
Gets the blue component of a color. Calculated from HSL where necessary via [this algorithm].
[hsl-to-rgb]: www.w3.org/TR/css3-color/#hsl-color
@overload blue($color) @param $color [Color] @return [Number] The blue component, between 0 and 255 inclusive @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 537 def blue(color) assert_type color, :Color, :color Sass::Script::Number.new(color.blue) end
Rounds a number up to the next whole number.
@example
ceil(10.4px) => 11px ceil(10.6px) => 11px
@overload ceil($value) @param $value [Number] @return [Number] @raise [ArgumentError] if ‘$value` isn’t a number
# File lib/sass/script/functions.rb, line 1232 def ceil(value) numeric_transformation(value) {|n| n.ceil} end
Changes one or more properties of a color. This can change the red, green, blue, hue, saturation, value, and alpha properties. The properties are specified as keyword arguments, and replace the color’s current value for that property.
All properties are optional. You can’t specify both RGB properties (‘$red`, `$green`, `$blue`) and HSL properties (`$hue`, `$saturation`, `$value`) at the same time.
@example
change-color(#102030, $blue: 5) => #102005 change-color(#102030, $red: 120, $blue: 5) => #782005 change-color(hsl(25, 100%, 80%), $lightness: 40%, $alpha: 0.8) => hsla(25, 100%, 40%, 0.8)
@overload change_color
($color, [$red], [$green], [$blue], [$hue], [$saturation], [$lightness], [$alpha]) @param $color [Color] @param $red [Number] The new red component for the color, within 0 and 255
inclusive
@param $green [Number] The new green component for the color, within 0 and
255 inclusive
@param $blue [Number] The new blue component for the color, within 0 and
255 inclusive
@param $hue [Number] The new hue component for the color, in degrees @param $saturation [Number] The new saturation component for the color,
between `0%` and `100%` inclusive
@param $lightness [Number] The new lightness component for the color,
within `0%` and `100%` inclusive
@param $alpha [Number] The new alpha component for the color, within 0 and
1 inclusive
@return [Color] @raise [ArgumentError] if any parameter is the wrong type or out-of
bounds, or if RGB properties and HSL properties are adjusted at the same time
# File lib/sass/script/functions.rb, line 962 def change_color(color, kwargs) assert_type color, :Color, :color with = Sass::Util.map_hash(%w[red green blue hue saturation lightness alpha]) do |name, max| next unless val = kwargs.delete(name) assert_type val, :Number, name [name.to_sym, val.value] end unless kwargs.empty? name, val = kwargs.to_a.first raise ArgumentError.new("Unknown argument $#{name} (#{val})") end color.with(with) end
Returns whether two numbers can added, subtracted, or compared.
@example
comparable(2px, 1px) => true comparable(100px, 3em) => false comparable(10cm, 3mm) => true
@overload comparable($number-1, $number-2) @param $number-1 [Number] @param $number-2 [Number] @return [Bool] @raise [ArgumentError] if either parameter is the wrong type
# File lib/sass/script/functions.rb, line 1185 def comparable(number_1, number_2) assert_type number_1, :Number, :number_1 assert_type number_2, :Number, :number_2 Sass::Script::Bool.new(number_1.comparable_to?(number_2)) end
Returns the complement of a color. This is identical to ‘adjust-hue(color, 180deg)`.
@see adjust_hue
adjust-hue @overload complement($color) @param $color [Color] @return [Color] @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 1063 def complement(color) adjust_hue color, Number.new(180) end
This function only exists as a workaround for IE7’s [‘content: counter` bug]. It works identically to any other plain-CSS function, except it avoids adding spaces between the argument commas.
[bug]: jes.st/2013/ie7s-css-breaking-content-counter-bug/
@example
counter(item, ".") => counter(item,".")
@overload counter($args…) @return [String]
# File lib/sass/script/functions.rb, line 1501 def counter(*args) Sass::Script::String.new("counter(#{args.map {|a| a.to_s(options)}.join(',')})") end
This function only exists as a workaround for IE7’s [‘content: counters` bug]. It works identically to any other plain-CSS function, except it avoids adding spaces between the argument commas.
[bug]: jes.st/2013/ie7s-css-breaking-content-counter-bug/
@example
counters(item, ".") => counters(item,".")
@overload counters($args…) @return [String]
# File lib/sass/script/functions.rb, line 1516 def counters(*args) Sass::Script::String.new("counters(#{args.map {|a| a.to_s(options)}.join(',')})") end
Makes a color darker. Takes a color and a number between 0% and 100%, and returns a color with the lightness decreased by that amount.
@see lighten
@example
darken(hsl(25, 100%, 80%), 30%) => hsl(25, 100%, 50%) darken(#800, 20%) => #200
@overload darken($color, $amount) @param $color [Color] @param $amount [Number] The amount to dencrease the lightness by, between
`0%` and `100%`
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 711 def darken(color, amount) _adjust(color, amount, :lightness, 0..100, :-, "%") end
Makes a color less saturated. Takes a color and a number between 0% and 100%, and returns a color with the saturation decreased by that value.
@see saturate
@example
desaturate(hsl(120, 30%, 90%), 20%) => hsl(120, 10%, 90%) desaturate(#855, 20%) => #726b6b
@overload desaturate($color, $amount) @param $color [Color] @param $amount [Number] The amount to decrease the saturation by, between
`0%` and `100%`
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 753 def desaturate(color, amount) _adjust(color, amount, :saturation, 0..100, :-, "%") end
Rounds a number down to the previous whole number.
@example
floor(10.4px) => 10px floor(10.6px) => 10px
@overload floor($value) @param $value [Number] @return [Number] @raise [ArgumentError] if ‘$value` isn’t a number
# File lib/sass/script/functions.rb, line 1246 def floor(value) numeric_transformation(value) {|n| n.floor} end
Converts a color to grayscale. This is identical to ‘desaturate(color, 100%)`.
@see desaturate
@overload grayscale($color) @param $color [Color] @return [Color] @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 1049 def grayscale(color) return Sass::Script::String.new("grayscale(#{color})") if color.is_a?(Sass::Script::Number) desaturate color, Number.new(100) end
Gets the green component of a color. Calculated from HSL where necessary via [this algorithm].
[hsl-to-rgb]: www.w3.org/TR/css3-color/#hsl-color
@overload green($color) @param $color [Color] @return [Number] The green component, between 0 and 255 inclusive @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 522 def green(color) assert_type color, :Color, :color Sass::Script::Number.new(color.green) end
Creates a {Color} from hue, saturation, and lightness values. Uses the algorithm from the [CSS3 spec][].
[CSS3 spec]: www.w3.org/TR/css3-color/#hsl-color
@see hsla
@overload hsl($hue, $saturation, $lightness) @param $hue [Number] The hue of the color. Should be between 0 and 360
degrees, inclusive
@param $saturation [Number] The saturation of the color. Must be between
`0%` and `100%`, inclusive
@param $lightness [Number] The lightness of the color. Must be between
`0%` and `100%`, inclusive
@return [Color] @raise [ArgumentError] if ‘$saturation` or `$lightness` are out of bounds
or any parameter is the wrong type
# File lib/sass/script/functions.rb, line 459 def hsl(hue, saturation, lightness) hsla(hue, saturation, lightness, Number.new(1)) end
Creates a {Color} from hue, saturation, lightness, and alpha values. Uses the algorithm from the [CSS3 spec][].
[CSS3 spec]: www.w3.org/TR/css3-color/#hsl-color
@see hsl
@overload hsla($hue, $saturation, $lightness, $alpha) @param $hue [Number] The hue of the color. Should be between 0 and 360
degrees, inclusive
@param $saturation [Number] The saturation of the color. Must be between
`0%` and `100%`, inclusive
@param $lightness [Number] The lightness of the color. Must be between
`0%` and `100%`, inclusive
@param $alpha [Number] The opacity of the color. Must be between 0 and 1,
inclusive
@return [Color] @raise [ArgumentError] if ‘$saturation`, `$lightness`, or `$alpha` are out
of bounds or any parameter is the wrong type
# File lib/sass/script/functions.rb, line 482 def hsla(hue, saturation, lightness, alpha) assert_type hue, :Number, :hue assert_type saturation, :Number, :saturation assert_type lightness, :Number, :lightness assert_type alpha, :Number, :alpha Sass::Util.check_range('Alpha channel', 0..1, alpha) h = hue.value s = Sass::Util.check_range('Saturation', 0..100, saturation, '%') l = Sass::Util.check_range('Lightness', 0..100, lightness, '%') Color.new(:hue => h, :saturation => s, :lightness => l, :alpha => alpha.value) end
Returns the hue component of a color. See [the CSS3 HSL specification]. Calculated from RGB where necessary via [this algorithm].
[hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV [rgb-to-hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV
@overload hue($color) @param $color [Color] @return [Number] The hue component, between 0deg and 360deg @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 554 def hue(color) assert_type color, :Color, :color Sass::Script::Number.new(color.hue, ["deg"]) end
Converts a color into the format understood by IE filters.
@example
ie-hex-str(#abc) => #FFAABBCC ie-hex-str(#3322BB) => #FF3322BB ie-hex-str(rgba(0, 255, 0, 0.5)) => #8000FF00
@overload ie_hex_str
($color) @param $color [Color] @return [String] The IE-formatted string representation of the color @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 788 def ie_hex_str(color) assert_type color, :Color, :color alpha = (color.alpha * 255).round.to_s(16).rjust(2, '0') Sass::Script::String.new("##{alpha}#{color.send(:hex_str)[1..-1]}".upcase) end
Returns one of two values, depending on whether or not ‘$condition` is true. Just like in `@if`, all values other than `false` and `null` are considered to be true.
@example
if(true, 1px, 2px) => 1px if(false, 1px, 2px) => 2px
@overload if($condition, $if-true, $if-false) @param $condition [Literal] Whether the ‘$if-true` or `$if-false` will be
returned
@param $if-true [Literal] @param $if-false [Literal] @return [Literal] ‘$if-true` or `$if-false`
# File lib/sass/script/functions.rb, line 1482 def if(condition, if_true, if_false) if condition.to_bool if_true else if_false end end
Returns the position of a value within a list. If the value isn’t found, returns false instead.
Note that unlike some languages, the first item in a Sass
list is number 1, the second number 2, and so forth.
@example
index(1px solid red, solid) => 2 index(1px solid red, dashed) => false
@overload index($list, $value) @param $list [Literal] @param $value [Literal] @return [Number, Bool] The 1-based index of ‘$value` in `$list`, or
`false`
# File lib/sass/script/functions.rb, line 1459 def index(list, value) index = list.to_a.index {|e| e.eq(value).to_bool } if index Number.new(index + 1) else Bool.new(false) end end
Returns the inverse (negative) of a color. The red, green, and blue values are inverted, while the opacity is left alone.
@overload invert($color) @param $color [Color] @return [Color] @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 1075 def invert(color) return Sass::Script::String.new("invert(#{color})") if color.is_a?(Sass::Script::Number) assert_type color, :Color, :color color.with( :red => (255 - color.red), :green => (255 - color.green), :blue => (255 - color.blue)) end
Joins together two lists into one.
Unless ‘$separator` is passed, if one list is comma-separated and one is space-separated, the first parameter’s separator is used for the resulting list. If both lists have fewer than two items, spaces are used for the resulting list.
@example
join(10px 20px, 30px 40px) => 10px 20px 30px 40px join((blue, red), (#abc, #def)) => blue, red, #abc, #def join(10px, 20px) => 10px 20px join(10px, 20px, comma) => 10px, 20px join((blue, red), (#abc, #def), space) => blue red #abc #def
@overload join($list1, $list2, $separator: auto) @param $list1 [Literal] @param $list2 [Literal] @param $separator [String] The list separator to use. If this is ‘comma`
or `space`, that separator will be used. If this is `auto` (the default), the separator is determined as explained above.
@return [List]
# File lib/sass/script/functions.rb, line 1362 def join(list1, list2, separator = Sass::Script::String.new("auto")) assert_type separator, :String, :separator unless %w[auto space comma].include?(separator.value) raise ArgumentError.new("Separator name must be space, comma, or auto") end sep1 = list1.separator if list1.is_a?(Sass::Script::List) && !list1.value.empty? sep2 = list2.separator if list2.is_a?(Sass::Script::List) && !list2.value.empty? Sass::Script::List.new( list1.to_a + list2.to_a, if separator.value == 'auto' sep1 || sep2 || :space else separator.value.to_sym end) end
Return the length of a list.
@example
length(10px) => 1 length(10px 20px 30px) => 3
@overload length($list) @param $list [Literal] @return [Number]
# File lib/sass/script/functions.rb, line 1307 def length(list) Sass::Script::Number.new(list.to_a.size) end
Makes a color lighter. Takes a color and a number between ‘0%` and `100%`, and returns a color with the lightness increased by that amount.
@see darken
@example
lighten(hsl(0, 0%, 0%), 30%) => hsl(0, 0, 30) lighten(#800, 20%) => #e00
@overload lighten($color, $amount) @param $color [Color] @param $amount [Number] The amount to increase the lightness by, between
`0%` and `100%`
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 692 def lighten(color, amount) _adjust(color, amount, :lightness, 0..100, :+, "%") end
Returns the lightness component of a color. See [the CSS3 HSL specification]. Calculated from RGB where necessary via [this algorithm].
[hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV [rgb-to-hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV
@overload lightness($color) @param $color [Color] @return [Number] The lightness component, between 0% and 100% @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 588 def lightness(color) assert_type color, :Color, :color Sass::Script::Number.new(color.lightness, ["%"]) end
Finds the maximum of several numbers. This function takes any number of arguments.
@example
max(1px, 4px) => 4px max(5em, 3em, 4em) => 5em
@overload max($numbers…) @param $numbers [[Number]] @return [Number] @raise [ArgumentError] if any argument isn’t a number, or if not all of
the arguments have comparable units
# File lib/sass/script/functions.rb, line 1293 def max(*values) values.each {|v| assert_type v, :Number} values.inject {|max, val| max.gt(val).to_bool ? max : val} end
Finds the minimum of several numbers. This function takes any number of arguments.
@example
min(1px, 4px) => 1px min(5em, 3em, 4em) => 3em
@overload min($numbers…) @param $numbers [[Number]] @return [Number] @raise [ArgumentError] if any argument isn’t a number, or if not all of
the arguments have comparable units
# File lib/sass/script/functions.rb, line 1276 def min(*numbers) numbers.each {|n| assert_type n, :Number} numbers.inject {|min, num| min.lt(num).to_bool ? min : num} end
Mixes two colors together. Specifically, takes the average of each of the RGB components, optionally weighted by the given percentage. The opacity of the colors is also considered when weighting the components.
The weight specifies the amount of the first color that should be included in the returned color. The default, ‘50%`, means that half the first color and half the second color should be used. `25%` means that a quarter of the first color and three quarters of the second color should be used.
@example
mix(#f00, #00f) => #7f007f mix(#f00, #00f, 25%) => #3f00bf mix(rgba(255, 0, 0, 0.5), #00f) => rgba(63, 0, 191, 0.75)
@overload mix($color-1, $color-2, $weight: 50%) @param $color-1 [Color] @param $color-2 [Color] @param $weight [Number] The relative weight of each color. Closer to ‘0%`
gives more weight to `$color`, closer to `100%` gives more weight to `$color2`
@return [Color] @raise [ArgumentError] if ‘$weight` is out of bounds or any parameter is
the wrong type
# File lib/sass/script/functions.rb, line 1001 def mix(color_1, color_2, weight = Number.new(50)) assert_type color_1, :Color, :color_1 assert_type color_2, :Color, :color_2 assert_type weight, :Number, :weight Sass::Util.check_range("Weight", 0..100, weight, '%') # This algorithm factors in both the user-provided weight (w) and the # difference between the alpha values of the two colors (a) to decide how # to perform the weighted average of the two RGB values. # # It works by first normalizing both parameters to be within [-1, 1], # where 1 indicates "only use color_1", -1 indicates "only use color_2", and # all values in between indicated a proportionately weighted average. # # Once we have the normalized variables w and a, we apply the formula # (w + a)/(1 + w*a) to get the combined weight (in [-1, 1]) of color_1. # This formula has two especially nice properties: # # * When either w or a are -1 or 1, the combined weight is also that number # (cases where w * a == -1 are undefined, and handled as a special case). # # * When a is 0, the combined weight is w, and vice versa. # # Finally, the weight of color_1 is renormalized to be within [0, 1] # and the weight of color_2 is given by 1 minus the weight of color_1. p = (weight.value/100.0).to_f w = p*2 - 1 a = color_1.alpha - color_2.alpha w1 = (((w * a == -1) ? w : (w + a)/(1 + w*a)) + 1)/2.0 w2 = 1 - w1 rgb = color_1.rgb.zip(color_2.rgb).map {|v1, v2| v1*w1 + v2*w2} alpha = color_1.alpha*p + color_2.alpha*(1-p) Color.new(rgb + [alpha]) end
Gets the nth item in a list.
Note that unlike some languages, the first item in a Sass
list is number 1, the second number 2, and so forth.
@example
nth(10px 20px 30px, 1) => 10px nth((Helvetica, Arial, sans-serif), 3) => sans-serif
@overload nth($list, $n) @param $list [Literal] @param $n [Number] The index of the item to get @return [Literal] @raise [ArgumentError] if ‘$n` isn’t an integer between 1 and the length
of `$list`
# File lib/sass/script/functions.rb, line 1326 def nth(list, n) assert_type n, :Number, :n if !n.int? raise ArgumentError.new("List index #{n} must be an integer") elsif n.to_i < 1 raise ArgumentError.new("List index #{n} must be greater than or equal to 1") elsif list.to_a.size == 0 raise ArgumentError.new("List index is #{n} but list has no items") elsif n.to_i > (size = list.to_a.size) raise ArgumentError.new("List index is #{n} but list is only #{size} item#{'s' if size != 1} long") end list.to_a[n.to_i - 1] end
Makes a color more opaque. Takes a color and a number between 0 and 1, and returns a color with the opacity increased by that amount.
@see transparentize
@example
opacify(rgba(0, 0, 0, 0.5), 0.1) => rgba(0, 0, 0, 0.6) opacify(rgba(0, 0, 17, 0.8), 0.2) => #001
@overload opacify($color, $amount) @param $color [Color] @param $amount [Number] The amount to increase the opacity by, between 0
and 1
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 648 def opacify(color, amount) _adjust(color, amount, :alpha, 0..1, :+) end
Returns the alpha component (opacity) of a color. This is 1 unless otherwise specified.
@overload opacity($color) @param $color [Color] @return [Number] The alpha component, between 0 and 1 @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 627 def opacity(color) return Sass::Script::String.new("opacity(#{color})") if color.is_a?(Sass::Script::Number) assert_type color, :Color, :color Sass::Script::Number.new(color.alpha) end
Converts a unitless number to a percentage.
@example
percentage(0.2) => 20% percentage(100px / 50px) => 200%
@overload percentage($value) @param $value [Number] @return [Number] @raise [ArgumentError] if ‘$value` isn’t a unitless number
# File lib/sass/script/functions.rb, line 1201 def percentage(value) unless value.is_a?(Sass::Script::Number) && value.unitless? raise ArgumentError.new("$value: #{value.inspect} is not a unitless number") end Sass::Script::Number.new(value.value * 100, ['%']) end
Add quotes to a string if the string isn’t quoted, or returns the same string if it is.
@see unquote
@example
quote("foo") => "foo" quote(foo) => "foo"
@overload quote($string) @param $string [String] @return [String] @raise [ArgumentError] if ‘$string` isn’t a string
# File lib/sass/script/functions.rb, line 1117 def quote(string) assert_type string, :String, :string Sass::Script::String.new(string.value, :string) end
Gets the red component of a color. Calculated from HSL where necessary via [this algorithm].
[hsl-to-rgb]: www.w3.org/TR/css3-color/#hsl-color
@overload red($color) @param $color [Color] @return [Number] The red component, between 0 and 255 inclusive @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 507 def red(color) assert_type color, :Color, :color Sass::Script::Number.new(color.red) end
Creates a {Color} object from red, green, and blue values.
@see rgba
@overload rgb($red, $green, $blue) @param $red [Number] The amount of red in the color. Must be between 0 and
255 inclusive, or between `0%` and `100%` inclusive
@param $green [Number] The amount of green in the color. Must be between 0
and 255 inclusive, or between `0%` and `100%` inclusive
@param $blue [Number] The amount of blue in the color. Must be between 0
and 255 inclusive, or between `0%` and `100%` inclusive
@return [Color] @raise [ArgumentError] if any parameter is the wrong type or out of bounds
# File lib/sass/script/functions.rb, line 377 def rgb(red, green, blue) assert_type red, :Number, :red assert_type green, :Number, :green assert_type blue, :Number, :blue Color.new([[red, :red], [green, :green], [blue, :blue]].map do |(c, name)| v = c.value if c.numerator_units == ["%"] && c.denominator_units.empty? v = Sass::Util.check_range("$#{name}: Color value", 0..100, c, '%') v * 255 / 100.0 else Sass::Util.check_range("$#{name}: Color value", 0..255, c) end end) end
Creates a {Color} from red, green, blue, and alpha values. @see rgb
@overload rgba($red, $green, $blue, $alpha)
@param $red [Number] The amount of red in the color. Must be between 0 and 255 inclusive @param $green [Number] The amount of green in the color. Must be between 0 and 255 inclusive @param $blue [Number] The amount of blue in the color. Must be between 0 and 255 inclusive @param $alpha [Number] The opacity of the color. Must be between 0 and 1 inclusive @return [Color] @raise [ArgumentError] if any parameter is the wrong type or out of bounds
@overload rgba($color, $alpha)
Sets the opacity of an existing color. @example rgba(#102030, 0.5) => rgba(16, 32, 48, 0.5) rgba(blue, 0.2) => rgba(0, 0, 255, 0.2) @param $color [Color] The color whose opacity will be changed. @param $alpha [Number] The new opacity of the color. Must be between 0 and 1 inclusive @return [Color] @raise [ArgumentError] if `$alpha` is out of bounds or either parameter is the wrong type
# File lib/sass/script/functions.rb, line 423 def rgba(*args) case args.size when 2 color, alpha = args assert_type color, :Color, :color assert_type alpha, :Number, :alpha Sass::Util.check_range('Alpha channel', 0..1, alpha) color.with(:alpha => alpha.value) when 4 red, green, blue, alpha = args rgba(rgb(red, green, blue), alpha) else raise ArgumentError.new("wrong number of arguments (#{args.size} for 4)") end end
Rounds a number to the nearest whole number.
@example
round(10.4px) => 10px round(10.6px) => 11px
@overload round($value) @param $value [Number] @return [Number] @raise [ArgumentError] if ‘$value` isn’t a number
# File lib/sass/script/functions.rb, line 1218 def round(value) numeric_transformation(value) {|n| n.round} end
Makes a color more saturated. Takes a color and a number between 0% and 100%, and returns a color with the saturation increased by that amount.
@see desaturate
@example
saturate(hsl(120, 30%, 90%), 20%) => hsl(120, 50%, 90%) saturate(#855, 20%) => #9e3f3f
@overload saturate($color, $amount) @param $color [Color] @param $amount [Number] The amount to increase the saturation by, between
`0%` and `100%`
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 730 def saturate(color, amount = nil) # Support the filter effects definition of saturate. # https://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/index.html return Sass::Script::String.new("saturate(#{color})") if amount.nil? _adjust(color, amount, :saturation, 0..100, :+, "%") end
Returns the saturation component of a color. See [the CSS3 HSL specification]. Calculated from RGB where necessary via [this algorithm].
[hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV [rgb-to-hsl]: en.wikipedia.org/wiki/HSL_and_HSV#Conversion_from_RGB_to_HSL_or_HSV
@overload saturation($color) @param $color [Color] @return [Number] The saturation component, between 0% and 100% @raise [ArgumentError] if ‘$color` isn’t a color
# File lib/sass/script/functions.rb, line 571 def saturation(color) assert_type color, :Color, :color Sass::Script::Number.new(color.saturation, ["%"]) end
Fluidly scales one or more properties of a color. Unlike {#adjust_color adjust-color}, which changes a color’s properties by fixed amounts, {#scale_color scale-color} fluidly changes them based on how high or low they already are. That means that lightening an already-light color with {#scale_color scale-color} won’t change the lightness much, but lightening a dark color by the same amount will change it more dramatically. This has the benefit of making ‘scale-color($color, …)` have a similar effect regardless of what `$color` is.
For example, the lightness of a color can be anywhere between ‘0%` and `100%`. If `scale-color($color, $lightness: 40%)` is called, the resulting color’s lightness will be 40% of the way between its original lightness and 100. If ‘scale-color($color, $lightness: -40%)` is called instead, the lightness will be 40% of the way between the original and 0.
This can change the red, green, blue, saturation, value, and alpha properties. The properties are specified as keyword arguments. All arguments should be percentages between ‘0%` and `100%`.
All properties are optional. You can’t specify both RGB properties (‘$red`, `$green`, `$blue`) and HSL properties (`$saturation`, `$value`) at the same time.
@example
scale-color(hsl(120, 70%, 80%), $lightness: 50%) => hsl(120, 70%, 90%) scale-color(rgb(200, 150%, 170%), $green: -40%, $blue: 70%) => rgb(200, 90, 229) scale-color(hsl(200, 70%, 80%), $saturation: -90%, $alpha: -30%) => hsla(200, 7%, 80%, 0.7)
@overload scale_color
($color, [$red], [$green], [$blue], [$saturation], [$lightness], [$alpha]) @param $color [Color] @param $red [Number] @param $green [Number] @param $blue [Number] @param $saturation [Number] @param $lightness [Number] @param $alpha [Number] @return [Color] @raise [ArgumentError] if any parameter is the wrong type or out-of
bounds, or if RGB properties and HSL properties are adjusted at the same time
# File lib/sass/script/functions.rb, line 896 def scale_color(color, kwargs) assert_type color, :Color, :color with = Sass::Util.map_hash({ "red" => 255, "green" => 255, "blue" => 255, "saturation" => 100, "lightness" => 100, "alpha" => 1 }) do |name, max| next unless val = kwargs.delete(name) assert_type val, :Number, name if !(val.numerator_units == ['%'] && val.denominator_units.empty?) raise ArgumentError.new("$#{name}: Amount #{val} must be a % (e.g. #{val.value}%)") else Sass::Util.check_range("$#{name}: Amount", -100..100, val, '%') end current = color.send(name) scale = val.value/100.0 diff = scale > 0 ? max - current : current [name.to_sym, current + diff*scale] end unless kwargs.empty? name, val = kwargs.to_a.first raise ArgumentError.new("Unknown argument $#{name} (#{val})") end color.with(with) end
Makes a color more transparent. Takes a color and a number between 0 and 1, and returns a color with the opacity decreased by that amount.
@see opacify
@example
transparentize(rgba(0, 0, 0, 0.5), 0.1) => rgba(0, 0, 0, 0.4) transparentize(rgba(0, 0, 0, 0.8), 0.2) => rgba(0, 0, 0, 0.6)
@overload transparentize($color, $amount) @param $color [Color] @param $amount [Number] The amount to decrease the opacity by, between 0
and 1
@return [Color] @raise [ArgumentError] if ‘$amount` is out of bounds, or either parameter
is the wrong type
# File lib/sass/script/functions.rb, line 670 def transparentize(color, amount) _adjust(color, amount, :alpha, 0..1, :-) end
Returns the type of a value.
@example
type-of(100px) => number type-of(asdf) => string type-of("asdf") => string type-of(true) => bool type-of(#fff) => color type-of(blue) => color
@overload type_of
($value) @param $value [Literal] The value to inspect @return [String] The unquoted string name of the value’s type
# File lib/sass/script/functions.rb, line 1135 def type_of(value) Sass::Script::String.new(value.class.name.gsub(/Sass::Script::/,'').downcase) end
Returns the unit(s) associated with a number. Complex units are sorted in alphabetical order by numerator and denominator.
@example
unit(100) => "" unit(100px) => "px" unit(3em) => "em" unit(10px * 5em) => "em*px" unit(10px * 5em / 30cm / 1rem) => "em*px/cm*rem"
@overload unit($number) @param $number [Number] @return [String] The unit(s) of the number, as a quoted string @raise [ArgumentError] if ‘$number` isn’t a number
# File lib/sass/script/functions.rb, line 1153 def unit(number) assert_type number, :Number, :number Sass::Script::String.new(number.unit_str, :string) end
Returns whether a number has units.
@example
unitless(100) => true unitless(100px) => false
@overload unitless($number) @param $number [Number] @return [Bool] @raise [ArgumentError] if ‘$number` isn’t a number
# File lib/sass/script/functions.rb, line 1168 def unitless(number) assert_type number, :Number, :number Sass::Script::Bool.new(number.unitless?) end
Removes quotes from a string. If the string is already unquoted, this will return it unmodified.
@see quote
@example
unquote("foo") => foo unquote(foo) => foo
@overload unquote($string) @param $string [String] @return [String] @raise [ArgumentError] if ‘$string` isn’t a string
# File lib/sass/script/functions.rb, line 1097 def unquote(string) if string.is_a?(Sass::Script::String) Sass::Script::String.new(string.value, :identifier) else string end end
Combines several lists into a single multidimensional list. The nth value of the resulting list is a space separated list of the source lists’ nth values.
The length of the resulting list is the length of the shortest list.
@example
zip(1px 1px 3px, solid dashed solid, red green blue) => 1px solid red, 1px dashed green, 3px solid blue
@overload zip($lists…) @param $lists [[Literal]] @return [List]
# File lib/sass/script/functions.rb, line 1428 def zip(*lists) length = nil values = [] lists.each do |list| array = list.to_a values << array.dup length = length.nil? ? array.length : [length, array.length].min end values.each do |value| value.slice!(length) end new_list_value = values.first.zip(*values[1..-1]) List.new(new_list_value.map{|list| List.new(list, :space)}, :comma) end
Private Instance Methods
# File lib/sass/script/functions.rb, line 1531 def _adjust(color, amount, attr, range, op, units = "") assert_type color, :Color, :color assert_type amount, :Number, :amount Sass::Util.check_range('Amount', range, amount, units) # TODO: is it worth restricting here, # or should we do so in the Color constructor itself, # and allow clipping in rgb() et al? color.with(attr => Sass::Util.restrict( color.send(attr).send(op, amount.value), range)) end
This method implements the pattern of transforming a numeric value into another numeric value with the same units. It yields a number to a block to perform the operation and return a number
# File lib/sass/script/functions.rb, line 1526 def numeric_transformation(value) assert_type value, :Number, :value Sass::Script::Number.new(yield(value.value), value.numerator_units, value.denominator_units) end