R/utils.R

In rheroicons: A Zero Dependency 'SVG' Icon Library for 'Shiny'

#' Process CSS Classes
#'
#' In the main icon function, the optional argument 'class' can be
#' used add custom CSS classes to an icon.
#'
#' @param svg a string containing the SVG markup of an icon
#' @param class a string containing one or more CSS classes
#'
#' @noRd
.set__classnames <- function(svg, class) {

  # extract SVG's css classes
  css <- stringr::str_extract(string = svg, pattern = "class=.([\\w\\s-]+).")

  # extract positions of \"
  css_pos <- stringr::str_locate_all(string = css, pattern = "\"")[[1]]

  # set new class attribute definition
  new_css <- paste0(
    stringr::str_sub(css, start = 1, end = css_pos[[2]] - 1),
    " ",
    class,
    "\""
  )

  stringr::str_replace(string = svg, pattern = css, replacement = new_css)
}