R DT::datatables formatting multiple columns simultaneously - r

Question

I wish to implement formatCurrency() and formatPercentage() (both from DT package) across multiple columns simultaneously in a shiny dashboard. I am using shinymaterial for the given example.
I am currently doing the following:
# The packages to load.
required_packages <- c("shiny", "shinymaterial", "DT", "tidyverse")
# This function will load in all the packages needed.
lapply(required_packages, require, character.only = TRUE)
# A table example.
ui <- material_page(
title = "Example table",
tags$h1("Table example"),
material_card(
title = "Table",
material_row(
DT::dataTableOutput("data_table_example")
),
depth = 1
)
)
server <- function(input, output) {
data_table_example_data = tibble(
Person = paste0("Person ", c(1:100)),
`Price $` = rnorm(100, 50000, 500),
`Cost $` = rnorm(100, 30000, 300),
`Probability %` = rnorm(100, 0.6, 0.1),
`Win %` = rnorm(100, 0.5, 0.2)
)
# This will create an output summary table
output$data_table_example = renderDataTable({
result = datatable(data_table_example_data, options = list(pageLength = 100, scrollX = TRUE),
class = 'cell-border stripe compact', rownames = FALSE) %>%
formatCurrency("Price $") %>%
formatCurrency("Cost $") %>%
formatPercentage("Probability %", digits = 1) %>%
formatPercentage("Win %", digits = 1)
})
}
shinyApp(ui = ui, server = server)
However, what I wish to do is, within the renderDataTable() function, to simplify the format functions into fewer lines. For example, implement formatCurrency() in any column with a "$" and formatPercentage() in any column with a "%".
I have done a fair bit of searching for an appropriate but could not find a solution, but I assume I am just missing a fairly simple solution.
Something like:
# This will create an output summary table
output$data_table_example = renderDataTable({
result = datatable(data_table_example_data, options = list(pageLength = 100, scrollX = TRUE),
class = 'cell-border stripe compact', rownames = FALSE) %>%
formatCurrency(grepl("$", colnames()) %>%
formatPercentage(grepl("%", colnames()), digits = 1)
})
A few additional points:
The tibble will actually be a reactive
This example is a very trivial version of a rather more complex table and set of reactives
I do not want to implement the formatting in the reactive part since I find this then messes with the DT sorting function, since it assumes the column is a character string
Any help will be greatly appreciated

Answer 1

Try:
# This will create an output summary table
output$data_table_example = renderDataTable({
result = datatable(data_table_example_data, options = list(pageLength = 100, scrollX = TRUE),
class = 'cell-border stripe compact', rownames = FALSE) %>%
formatCurrency(grepl("$", colnames(data_table_example_data)) %>%
formatPercentage(grepl("%", colnames(data_table_example_data)), digits = 1)
})
It seems you need to be explicit with the data so colnames() doesn't work - you need colnames(data_table_example_data).
I noticed during testing if you use grepl with rownames = TRUE that rownames becomes the first column name which means all the formatting is out by one. grep seems to not have this issue.