CSS string helper

Convenience function for building CSS style declarations (i.e. the string that goes into a style attribute, or the parts that go inside curly braces in a full stylesheet).

css(..., collapse_ = "")

Arguments

...

Named style properties, where the name is the property name and the argument is the property value. See Details for conversion rules.

collapse_

(Note that the parameter name has a trailing underscore character.) Character to use to collapse properties into a single string; likely "" (the default) for style attributes, and either "\n" or NULL for style blocks.

Details

CSS uses '-' (minus) as a separator character in property names, but this is an inconvenient character to use in an R function argument name. Instead, you can use '.' (period) and/or '_' (underscore) as separator characters. For example, css(font.size = "12px") yields "font-size:12px;".

To mark a property as !important, add a '!' character to the end of the property name. (Since '!' is not normally a character that can be used in an identifier in R, you'll need to put the name in double quotes or backticks.)

Argument values will be converted to strings using paste(collapse = " "). Any property with a value of NULL or "" (after paste) will be dropped.

Examples

padding <- 6
css(
  font.family = "Helvetica, sans-serif",
  margin = paste0(c(10, 20, 10, 20), "px"),
  "padding!" = if (!is.null(padding)) padding
)
#> [1] "font-family:Helvetica, sans-serif;margin:10px 20px 10px 20px;padding:6 !important;"