README
¶
Go Language CSS Color Parser Library
Go library for parsing CSS color string as defined in the W3C's CSS Color Module Level 4. It supports parsing for absolute and relative color formats.
Supported Color Format
- Named colors
- RGB hexadecimal (with and without
#prefix)- Short format
#rgb - Short format with alpha
#rgba - Long format
#rrggbb - Long format with alpha
#rrggbbaa
- Short format
rgb()andrgba()hsl()andhsla()hwb()lab()lch()oklab()oklch()color(srgb ...)color(srgb-linear ...)color(xyz ...)color(xyz-d50 ...)color(xyz-d65 ...)hwba(),hsv(),hsva()- not in CSS standard.
Usage Examples
import "github.com/mazznoer/csscolorparser"
Parse Single Color
c, err := csscolorparser.Parse("gold")
if err != nil {
panic(err)
}
fmt.Printf("R:%.3f, G:%.3f, B:%.3f, A:%.3f", c.R, c.G, c.B, c.A) // R:1.000, G:0.843, B:0.000, A:1.000
fmt.Println(c.RGBA255()) // 255 215 0 255
fmt.Println(c.HexString()) // #ffd700
fmt.Println(c.RGBString()) // rgb(255 215 0)
Parse Multiple Colors
for c, err := range csscolorparser.ParseColors("red, #00ff00, rgb(0, 0, 255)") {
if err != nil {
fmt.Println(err)
continue
}
fmt.Println(c.HexString())
}
Try It Online
Similar Projects
- csscolorparser (Rust)
- csscolorparser (Javascript)
Documentation
¶
Overview ¶
Package csscolorparser provides function for parsing CSS color string as defined in the W3C's CSS color module level 4.
Example ¶
package main
import (
"fmt"
"github.com/mazznoer/csscolorparser"
)
func main() {
c, err := csscolorparser.Parse("rgb(100% 0% 0% / 50%)")
if err != nil {
panic(err)
}
fmt.Printf("R:%.3f, G:%.3f, B:%.3f, A:%.3f\n", c.R, c.G, c.B, c.A)
fmt.Println(c.RGBA255())
fmt.Println(c.HexString())
fmt.Println(c.RGBString())
}
Output: R:1.000, G:0.000, B:0.000, A:0.500 255 0 0 128 #ff000080 rgb(255 0 0 / 50%)
Index ¶
- Variables
- func ParseColors(s string) iter.Seq2[Color, error]
- type Color
- func FromHsl(h, s, l, a float64) Color
- func FromHsv(h, s, v, a float64) Color
- func FromHwb(h, w, b, a float64) Color
- func FromLab(l, a, b, alpha float64) Color
- func FromLch(l, c, h, alpha float64) Color
- func FromLinearRGB(r, g, b, a float64) Color
- func FromOklab(l, a, b, alpha float64) Color
- func FromOklch(l, c, h, alpha float64) Color
- func FromXyzD50(x, y, z, alpha float64) Color
- func FromXyzD65(x, y, z, alpha float64) Color
- func Parse(s string) (Color, error)
- func (c Color) Clamp() Color
- func (c Color) HexString() string
- func (c Color) Hsl() [4]float64
- func (c Color) Hwb() [4]float64
- func (c Color) Lab() [4]float64
- func (col Color) Lch() [4]float64
- func (c Color) LinearRgb() [4]float64
- func (c Color) MarshalText() ([]byte, error)
- func (c Color) Name() (string, bool)
- func (col Color) Oklab() [4]float64
- func (col Color) Oklch() [4]float64
- func (c Color) RGBA() (r, g, b, a uint32)
- func (c Color) RGBA255() (r, g, b, a uint8)
- func (c Color) RGBString() string
- func (c *Color) UnmarshalText(text []byte) error
- func (c Color) XyzD50() [4]float64
- func (c Color) XyzD65() [4]float64
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrInvalidHex = errors.New("invalid hex") ErrInvalidRgb = errors.New("invalid rgb") ErrInvalidHsl = errors.New("invalid hsl") ErrInvalidHwb = errors.New("invalid hwb") ErrInvalidHsv = errors.New("invalid hsv") ErrInvalidLab = errors.New("invalid lab") ErrInvalidLch = errors.New("invalid lch") ErrInvalidOklab = errors.New("invalid oklab") ErrInvalidOklch = errors.New("invalid oklch") ErrInvalidColor = errors.New("invalid color") ErrInvalidFunction = errors.New("invalid function") ErrInvalidUnknown = errors.New("invalid unknown") )
var NamedColors = map[string][3]uint8{}/* 148 elements not displayed */
Functions ¶
func ParseColors ¶ added in v0.2.0
ParseColors returns an iterator that lazily parses a comma-separated list of CSS colors.
Commas inside parentheses are not treated as separators, so functional notations such as "rgb(255, 0, 0)" or "hsl(120, 100%, 50%)" stay intact. Empty entries (e.g. from a trailing comma) are skipped.
Each iteration yields the parsed color and an error. If a color fails to parse, the error includes the offending token and iteration continues, letting the caller decide whether to stop (break) or skip.
Example:
for c, err := range csscolorparser.ParseColors("red, #00ff00, rgb(0, 0, 255)") {
if err != nil {
log.Println(err)
continue
}
fmt.Println(c.HexString())
}
Types ¶
type Color ¶
type Color struct {
R, G, B, A float64
}
R, G, B, A values in the range 0..1
func FromHsl ¶ added in v0.1.4
FromHsl creates a Color from HSL colors.
Arguments:
- h: Hue angle [0..360]
- s: Saturation [0..1]
- l: Lightness [0..1]
- a: Alpha [0..1]
func FromHsv ¶ added in v0.1.4
FromHsv creates a Color from HSV colors.
Arguments:
- h: Hue angle [0..360]
- s: Saturation [0..1]
- v: Value [0..1]
- a: Alpha [0..1]
func FromHwb ¶ added in v0.1.4
FromHwb creates a Color from HWB colors.
Arguments:
- h: Hue angle [0..360]
- w: Whiteness [0..1]
- b: Blackness [0..1]
- a: Alpha [0..1]
func FromLinearRGB ¶ added in v0.1.4
FromLinearRGB creates a Color from linear-light RGB colors.
Arguments:
- r: Red value [0..1]
- g: Green value [0..1]
- b: Blue value [0..1]
- a: Alpha value [0..1]
func FromOklab ¶ added in v0.1.4
FromOklab creates a Color from Oklab colors.
Arguments:
- l: Perceived lightness
- a: How green/red the color is
- b: How blue/yellow the color is
- alpha: Alpha [0..1]
func FromOklch ¶ added in v0.1.4
FromOklch creates a Color from OKLCh colors.
Arguments:
- l: Perceived lightness
- c: Chroma
- h: Hue angle in radians
- alpha: Alpha [0..1]
func FromXyzD50 ¶ added in v0.2.0
func FromXyzD65 ¶ added in v0.2.0
func (Color) MarshalText ¶ added in v0.1.3
Implement the Go TextMarshaler interface
func (Color) Name ¶ added in v0.1.3
Name returns name of this color if its available.
Example ¶
package main
import (
"fmt"
"github.com/mazznoer/csscolorparser"
)
func main() {
c, err := csscolorparser.Parse("#ffd700")
if err != nil {
panic(err)
}
fmt.Println(c.RGBString())
name, _ := c.Name()
fmt.Println(name)
}
Output: rgb(255 215 0) gold
func (*Color) UnmarshalText ¶ added in v0.1.3
Implement the Go TextUnmarshaler interface
Source Files