Special zero value in gt tables

Question

I'm using the {gt} package to create tables in a report. I would like it so that the "$0.00" currency values are replaced with "-", which is something that's easy to do in Excel but seems surprisingly hard to do with {gt}. Here is an example of a table I would like to have the zero values replaced with something easier on the eyes. The best I can seem to do is use fmt and make a custom function that recreates the entire functionality of fmt_currency, which doesn't seem great.

library(gt)
library(magrittr)
data <- data.frame(x=c(1.23,4.56,0,0,0,0,0))
table <- gt(data) %>%
  fmt_currency(x)

Answer 1

I think that gt::text_transform() can solve your immediate problem.

library(gt)
library(magrittr)
data <- data.frame(x=c(1.23,4.56,0,0,0,50,1.5))
table <- data %>% 
  gt() %>%
  fmt_currency(x)

table

table %>% 
  text_transform(
    locations = cells_body(
      x,
      rows = x==0
    ),
    fn = function(x){
      "-"
    }
  )

Multiple Columns

If you want to do it across multiple columns, you may want to also wrap it into a function and call against specific columns.

data <- data.frame(
  x = c( 0, -0.230, 0, -0.445, 0),
  y = c( -0.230, 0.0705, 0.460, -0.686, 0),
  z = c( 0, 0, 0.07, 0.129, -0.68)
)

currency_dash <- function(gt_data, col_name) {
  text_transform(
    gt_data,
    locations = cells_body(
      columns = {{ col_name }},
      rows = {{ col_name }} == 0
    ),
    fn = function(x) {
      "-"
    }
  )
}

data %>% 
  gt() %>% 
  fmt_currency(columns = everything()) %>% 
  currency_dash(x) %>% 
  currency_dash(y) %>% 
  currency_dash(z)

General Transform

But you'd likely be better suited with just putting the logic into the text_transform().

data <- data.frame(
  x = c( 0, -0.230, 0, -0.445, 0),
  y = c( -0.230, 0.0705, 0.460, -0.686, 0),
  z = c( 0, 0, 0.07, 0.129, -0.68)
)

table_currency <- data %>% 
  gt() %>% 
  fmt_currency(everything()) 

table_currency %>% 
  text_transform(
    locations = cells_body(),
    fn = function(x) ifelse(x == "$0.00", "-", x))
  )