footnote_options {ftExtra}

Options for footnotes

Description

Configure options for footnotes.

Usage

footnote_options(
  ref = c("1", "a", "A", "i", "I", "*"),
  prefix = "",
  suffix = "",
  start = 1L,
  max = 26L,
  inline = FALSE,
  sep = "; "
)

Arguments

ref

A string or a function that defines symbols of footnote references. If the value is string, it must be one of the "1", "a", "A", "i", "I", or "*". If a function, keep in mind this is an experimental feature. It receives 3 parameters (n, part, and footer) and returns character vectors which will further be processed as markdown. See examples for the details.

prefix, suffix

Pre- and suf-fixes for ref (default: ""). These parameters are used if and only if ref is a character.

start

A starting number of footnotes.

max

A max number of footnotes used only when ref is "a" or "A".

inline

whether to add footnote on same line as previous footnote or not

sep

used only when inline = TRUE, character string to use as a separator between footnotes.

Value

An environment

Examples

# A examole flextable with unprocessed markdown footnotes
ft <- flextable(tibble::tibble(
  "header1^[note a]" = c("x^[note 1]", "y"),
  "header2" = c("a", "b^[note 2]")
))

# Render all footnotes in the same format.
if (rmarkdown::pandoc_available("2.0.6")) {
  ft %>%
    colformat_md(
      part = "all",
      .footnote_options = footnote_options("1", start = 1L)
    )
}

# Use a user-defined function to format footnote symbols
# Skipped to reduce build time
if (FALSE) {
  # a function to format symbols of footnote references
  ref <- function(n, part, footer) {
    # Change symbols by context
    # - header: letters (a, b, c, ...)
    # - body: integers (1, 2, 3, ...)
    s <- if (part == "header") {
      letters[n]
    } else {
      as.character(n)
    }

    # Suffix symbols with ": " (a colon and a space) in the footer
    if (footer) {
      return(paste0(s, ":\\ "))
    }

    # Use superscript in the header and the body
    return(paste0("^", s, "^"))
  }

  # apply custom format of symbols
  ft %>%
    # process header first
    colformat_md(
      part = "header", .footnote_options = footnote_options(ref = ref)
    ) %>%
    # process body next
    colformat_md(
      part = "body", .footnote_options = footnote_options(ref = ref)
    ) %>%
    # tweak width for visibility
    flextable::autofit(add_w = 0.2)
}