dsl-html-attributes.R

html_attributes <- function(list) {
  if (length(list) == 0) {
    return("")
  }

  attr <- map2_chr(names(list), list, html_attribute)
  paste0(" ", unlist(attr), collapse = "")
}
html_attribute <- function(name, value = NULL) {
  if (length(value) == 0) {
    return(name)
  } # for attributes with no value
  if (length(value) != 1) stop("`value` must be NULL or length 1")

  if (is.logical(value)) {
    # Convert T and F to true and false
    value <- tolower(value)
  } else {
    value <- escape_attr(value)
  }
  paste0(name, "='", value, "'")
}
escape_attr <- function(x) {
  x <- escape.character(x)
  x <- gsub("\'", "&#39;", x)
  x <- gsub("\"", "&quot;", x)
  x <- gsub("\r", "&#13;", x)
  x <- gsub("\n", "&#10;", x)
  x
}