Adding an image in tooltip of ggRadar

Goal

I want to display images based on a column containing local/external url of images in a radar chart.

Reproducible Example

This is possible for a bar chart with ggiraph as shown below:

require(ggplot2)
require(ggiraph)
require(ggiraphExtra)

# Sample image
mtcars$gif_link <-"https://media.giphy.com/media/rrmf3fICPZWg1MMXOW/giphy.gif" 
mtcars$model <- row.names(mtcars)

# Create a ggplot object with interactivity using ggiraph
gg <- ggplot(mtcars, aes(y = as.factor(am), x = mpg)) +
  geom_bar_interactive(aes(tooltip = paste(model, "<img src=", shQuote(gif_link), " height='100'>")), stat = "identity") +
  theme_minimal()

# Display the ggiraph object
girafe(ggobj = gg)  

But it doesn't work with ggRadar:

ggRadar(data  =mtcars, aes(colour=am,
                           tooltip = paste(model, "<img src=", shQuote(gif_link), " height='100'>")),
        interactive=TRUE)
Error in `[.data.frame`(data, groupvar) : undefined columns selected  

I am open to using any other package/method that would achieve my goal.

One option would be to build your radar chart from scratch which requires some effort including some data wrangling but gives you all the flexibility of ggiraph:

library(ggplot2)
library(ggiraph)
library(ggiraphExtra)
library(dplyr)

mtcars2 <- mtcars

gg <- mtcars2 |>
  mutate(
    across(-am, ~ (.x - min(.x)) / diff(range(.x)))
  ) |>
  group_by(am) |>
  summarise(across(everything(), mean), .groups = "drop") |>
  tidyr::pivot_longer(-am, names_to = "variable") |>
  arrange(am, variable) |>
  mutate(gif_link = "https://media.giphy.com/media/rrmf3fICPZWg1MMXOW/giphy.gif") |>
  ggplot(aes(
    x = variable, y = value,
    colour = factor(am), fill = factor(am), group = factor(am)
  )) +
  geom_polygon_interactive(alpha = 0.3) +
  geom_point_interactive(
    aes(tooltip = paste0(
      "<i>am:</i> ", am,
      "<br>",
      "<i>", variable, ":</i> ", round(value, 1),
      "<br>",
      "<img src=", shQuote(gif_link), " height='100'>"
    )),
    size = 3
  ) +
  coord_radar()

girafe(ggobj = gg)

EDIT Following this answer we could add local images by wrapping in base64enc::dataURI(). In the code below I download the R logo and add it as local image:

path <- tempdir()
download.file(
  "https://www.r-project.org/logo/Rlogo.png",
  file.path(path, "RLogo.png")
)
gg <- mtcars2 |>
  mutate(
    across(-am, ~ (.x - min(.x)) / diff(range(.x)))
  ) |>
  group_by(am) |>
  summarise(across(everything(), mean), .groups = "drop") |>
  tidyr::pivot_longer(-am, names_to = "variable") |>
  arrange(am, variable) |>
  ggplot(aes(
    x = variable, y = value,
    colour = factor(am), fill = factor(am), group = factor(am)
  )) +
  geom_polygon_interactive(alpha = 0.3) +
  geom_point_interactive(
    aes(tooltip = paste0(
      "<i>am:</i> ", am,
      "<br>",
      "<i>", variable, ":</i> ", round(value, 1),
      "<br>",
      "<img src=", base64enc::dataURI(file = file.path(path, "RLogo.png")),
      " height='100'>"
    )),
    size = 3
  ) +
  coord_radar()

girafe(ggobj = gg)