Feature request: "fmt_accounting()"

[steveputman]

This was referred to in passing in #1, but it would be wonderful to be able to format negative numbers with parentheses. The formattable package had this (though I note that there are some annoyances with alignment, more so in pdf than in html).

Thanks again for the great package!

[rich-iannone]

You’re in luck because we already have this functionality. I think it’s probably badly named though: the argument negative_val can be set to parens in fmt_number() and some other functions as well.

[steveputman]

Ha! Awesome--sorry I didn't failed to track that down on my own (read all the code, Steve).

[steveputman]

I made some changes on my fork to deal with the alignment issues when using parentheses (typically you want the last digit of the positive number to line up with the last digit of the negative number rather than the parenthesis). The modification appends hphantom{(} in LaTeX or a hidden <span> with a parenthesis in HTML to all non-negative numbers to make the alignment work in fmt_number(), fmt_percent(), and fmt_currency().

Not the prettiest solution, but it seems to work. Happy to prepare PR if interested.

[rich-iannone]

@steveputman I'm looking for alignment solutions in general, so this is great! I'll reopen this issue (where you could show the API usage and outputs) and please do start a PR (and we can discuss the implementation more in there). Thanks!

[steveputman]

Great. The idea was to honor whatever was passed in cols_align, so no API changes (unless for some reason, one needed the option of aligning the paren with the digit).

With this code in an R Markdown file (varying the output parameter):

---
title: "parens_alignment"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)

library(tidyverse)
library(gt)

df <- tribble(
  ~chars, ~dates, ~curr, ~num, ~pct,
  "rowA", "2018-01-01", 1000.25, 0, .353,
  "rowB", "2018-01-02", -24.37, 10000.823, 0,
  "rowC", "2018-01-03", 0, -.7209, 0.234,
  "rowD", "2018-01-04", -24385.1, 288.21, -1.399
  ) 

rightalign <- df %>%
  gt() %>%
  tab_header(
    title = "Default alignment",
    subtitle = "-"
  ) %>%
  fmt_currency(
    columns = vars(curr),
    negative_val = "parens"
  ) %>%
  fmt_number(
    columns = vars(num),
    negative_val = "parens"
  ) %>%
  fmt_percent(
    columns = vars(pct),
    negative_val = "parens"
  ) 

leftalign <- rightalign %>%
  tab_header(
    title = "Left alignment",
    subtitle = "-"
  ) %>%
  cols_align(
    align = "left"
  )

centeralign <- rightalign %>%
  tab_header(
    title = "Center alignment",
    subtitle = "-"
  ) %>%
  cols_align(
    align = "center"
  )
```
`r rightalign`

`r leftalign`

`r centeralign`

You get this output in pdf:
parens_alignment.pdf

And this in html: