Applying text_transform() to row groups in R gt - r

Question

In the {gt} package I want to use text_transform() on the row group titles in order to render the HTML but I'm getting the `no applicable method for 'resolve_location' error.
In my example below, you can see that text_transform() works if the locations argument is cells_body() (which is not what I actually want) but not if it's cells_row_groups() which is what I want.
Thoughts?
Zev
# As an experiment, I put HTML in both a value and in the groups, though
# in the real data there is only HTML in groups.
tbl <- tibble(values = c("test<sup>2</sup>", 2:4), groups = c("x<sup>2</sup>", "x<sup>2</sup>", "y", "y"))
unescape_html <- function(str){
xml2::xml_text(xml2::read_html(paste0("<x>", str, "</x>")))
}
# Error, no applicable method for resolve_location
tbl |>
gt::gt(groupname_col = "b") |>
gt::text_transform(
locations = gt::cells_row_groups(),
fn = function(x){
x <- purrr::map_chr(x, unescape_html)
paste("<span style=color:red;>", x, "</span>")
}
)
# This works so it shows that I'm close :)
tbl |>
gt::gt(groupname_col = "b") |>
gt::text_transform(
locations = gt::cells_body(columns = 1),
fn = function(x){
x <- purrr::map_chr(x, unescape_html)
paste("<span style=color:red;>", x, "</span>")
}
)

Answer 1

After some trial and error and a look at the rendered html code I figured out a solution using gt::html:
tbl <- tibble::tibble(values = c("test<sup>2</sup>", 2:4), groups = c("x<sup>2</sup>", "x<sup>2</sup>", "y", "y"))
unescape_html <- function(str){
xml2::xml_text(xml2::read_html(paste0("<x>", str, "</x>")))
}
tbl |>
gt::gt(groupname_col = "groups") |>
gt::text_transform(
locations = gt::cells_row_groups(),
fn = function(x) {
purrr::map(x, ~ gt::html(paste("<span style=color:blue;>", .x, "</span>")))
}
) |>
gt::text_transform(
locations = gt::cells_body(columns = 1),
fn = function(x){
x <- purrr::map_chr(x, unescape_html)
paste("<span style=color:red;>", x, "</span>")
}
)