title: How to add median value into the tooltip to geom_boxplot_interactive without calculating beforehand?
body: <p>I'm trying to add the median value into the tooltip in <code>geom_boxplot_interactive(tooltip = )</code>, without having to calculate it for each grouping and joining it to the dataset.</p>
  
  <p>I have tried to see if something in <code>stat_summary()</code>, stat or middle would work. But no luck so far.</p>
  
  <pre><code>library(ggplot2) 
  library(ggiraph) 
  data("mpg") 
  # View(mpg) 
  p &lt;- ggplot(mpg, aes(x = class, y = hwy, tooltip = class)) + 
    geom_boxplot_interactive() 
  
  ggiraph(code = print(p))
  # ggiraph(ggobj = p  + geom_boxplot_interactive(aes(tooltip = data$median)) 
  
  p &lt;- ggplot(mpg, aes(x = drv, y = hwy, tooltip = class, fill = class)) +
    geom_boxplot_interactive(outlier.colour = "red") + 
    guides(fill = "none") + theme_minimal()
  
  girafe(ggobj = p)
  </code></pre>
  
  <p>This works if I have the median value for each group in the dataset, but I am trying to avoid this if possible.</p>