parseCssColors: Parse CSS color strings

In htmltools: Tools for HTML

Parse CSS color strings

Description

Parses/normalizes CSS color strings, and returns them as strings in "#RRGGBB" and/or "#RRGGBBAA" format. Understands hex colors in 3, 4, 6, and 8 digit forms, rgb()/rgba(), hsl()/hsla(), and color keywords.

Usage

parseCssColors(str, mustWork = TRUE)

Arguments

str	CSS color strings
mustWork	If true, invalid color strings will cause an error; if false, then the result will contain NA for invalid colors.

Details

Note that parseCssColors may return colors in ⁠#RRGGBBAA⁠ format. Such values are not understood by Internet Explorer, and must be converted to rgba(red, green, blue, alpha) format to be safe for the web.

Value

A vector of strings in ⁠#RRGGBB⁠ or ⁠#RRGGBBAA⁠ format (the latter is only used for colors whose alpha values are less than FF), or NA for invalid colors when mustWork is false. Such strings are suitable for use in plots, or parsing with col2rgb() (be sure to pass alpha = TRUE to prevent the alpha channel from being discarded).

Examples

parseCssColors(c(
  "#0d6efd",
  "#DC35457F",
  "rgb(32,201,151)",
  "  rgba( 23 , 162 , 184 , 0.5 )  ",
  "hsl(261, 51%, 51%)",
  "cornflowerblue"
))

htmltools documentation built on Nov. 3, 2023, 5:07 p.m.