R: Parse CSS color strings

parseCssColors {htmltools} | R Documentation

## 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"
    ))

[Package htmltools version 0.5.1.1 Index]