R/footnote_marker.R

#' Footnote marker
#' @export
footnote_marker_number <- function(x, format) {
  if (missing(format) || is.null(format)) {
    format <- getOption('knitr.table.format')
  }
  if (is.null(format)) {
    message("Setting footnote_marker_number format as html")
    format <- "html"
  }
  if (format == "html") {
    return(paste0("<sup>", x, "</sup>"))
  } else {
    return(paste0("\\textsuperscript{", x, "}"))
  }
}

#' @export
footnote_marker_alphabet <- function(x, format) {
  if (missing(format) || is.null(format)) {
    format <- getOption('knitr.table.format')
  }
  if (is.null(format)) {
    message("Setting footnote_marker_alphabet format as html")
    format <- "html"
  }
  if (is.numeric(x)) x <- letters[x]
  if (format == "html") {
    return(paste0("<sup>", x, "</sup>"))
  } else {
    return(paste0("\\textsuperscript{", x, "}"))
  }
}

#' @export
footnote_marker_symbol <- function(x, format) {
  if (missing(format) || is.null(format)) {
    format <- getOption('knitr.table.format')
  }
  if (is.null(format)) {
    message("Setting footnote_marker_symbol format as html")
    format <- "html"
  }
  number_index <- read.csv(system.file("symbol_index.csv",
                                       package = "kableExtra"))
  if (format == "html") {
    x <- number_index$symbol.html[x]
    return(paste0("<sup>", x, "</sup>"))
  } else {
    x <- number_index$symbol.latex[x]
    return(paste0("\\textsuperscript{", x, "}"))
  }
}