Consider making add_ggplot as an S3 generic #4743
Description
Would it be possible to make add_ggplot as an S3 generic?
Currently we have to resort to overwriting "+.gg" if we want to adopt a different method based on the class of e1, e.g. GGally is a prime example of this. This allows developers to fix issues like #4304 .
The fix, as below, will be relatively simple, but the downside is that you do have to export another function.
#' @export
add_ggplot <- function(p, object, objectname) {
UseMethod("add_ggplot")
}
#' @export
add_ggplot.ggplot <- function(p, object, objectname) {
if (is.null(object)) return(p)
p <- plot_clone(p)
p <- ggplot_add(object, p, objectname)
set_last_plot(p)
p
}