Rendering math symbols in datatable

Question

How can I pass latex symbol code to a datatable in R? I found this post, but I don't know JS and have no idea how to implement something like this in R.

[Edit] I have also tried the LaTeX solution from this post but got a blank table in return.

MWE

library(DT)

df <- data.frame(var1 = c("A", "B"),
                 var2 = c("this string contains $\\alpha$", "this one $\\beta$"))

df %>%
  datatable(
    rownames = FALSE, escape = TRUE,
    colnames = c("Col1", "Col2"), 
    filter = "top"
  )

Answer 1

Then you might build a katex_htmls() that replaces the tex from between each $ with a translation to "katex html":

library(dplyr)
library(DT)
library(katex)
library(purrr)
library(stringr)

# vectorized katex_html() with sensible settings for non-interactive use
katex_html_vec <- function(
    tex, 
    displayMode = FALSE, 
    ..., 
    include_css = TRUE, 
    preview = FALSE
  ) {
  purrr::map_chr(tex, ~ {
    katex::katex_html(
      .x, 
      displayMode = displayMode,
      ..., 
      include_css = include_css, 
      preview = preview
    )
  })
}

# katex_html_vec() to process 0 or more $tex$s per string
katex_htmls <- function(
    x,
    displayMode = FALSE, 
    ..., 
    include_css = TRUE, 
    preview = FALSE
  ) {
  purrr::map_chr(x, ~ {
    stringr::str_replace_all(.x, "\\$.*?\\$", function(m) {
      m %>% 
        stringr::str_remove_all("\\$") %>% 
        katex_html_vec(
          displayMode = displayMode, 
          ..., 
          include_css = include_css, 
          preview = preview
        )
    })
  })
}

data.frame(
  var1 = c("A", "B"),
  var2 = c("this string contains $\\alpha$", "this one $\\beta$")
) %>% 
  mutate(var2 = katex_htmls(var2)) %>% 
  datatable(
    rownames = FALSE,
    colnames = c("Col1", "Col2"), 
    filter = "top",
    escape = FALSE
  )

^{Created on 2024-04-19 with reprex v2.1.0}