htmltools: parseCssColors – R documentation

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parseCssColors

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

Tools for HTML

v0.5.1.1

GPL (>= 2)

Authors

Joe Cheng [aut], Carson Sievert [aut, cre] (<https://orcid.org/0000-0002-4958-2844>), Winston Chang [aut], Yihui Xie [aut], Jeff Allen [aut], RStudio [cph]

Initial release