R - upload current ggplot2 to imgur - r

Question

The imguR package seems to be exactly what I want, but a scan of the docs makes it seem like it only uploads files. Can I upload the current plot device without outputting to a file? Specifically I'm interested in uploading plots created with ggplot2. Here is what I tried:
> token = imgur_login()
> ggplot(dstat, aes(x=obs,y=tcp)) + geom_line() + theme_bw()
> upload_image(token=token)
Error in file.exists(file) : argument "file" is missing, with no default
EDIT: I should add, I'm comfortable with a method that invisibly creates a file in the background then uploads it, this is just for quick showcasing of plots not for perfect presentation
EDIT: Here is the code I have created so far. It does not work well because there seems to be a cache used inside of account_albums that is not easily disabled. Any help finalizing this would be appreciated
get_or_create_album = function(token) {
# I can find no way to disable the cache inside
# account_albums - it always returns the first
# result unless you login again.
# So if this function creates the album, then
# the user must manually log out and log back in
# or this function will happily continue creating the album
albums = account_albums(ids=F,token=token)
albums = data.frame(t(sapply(albums,c)))
album = albums$id[albums$title == "R ggplot2"]
if (length(album) >= 1)
return(album[[1]])
album = create_album(title='R ggplot2',description='Automatic uploads from ggplot2',privacy='public', token=token)
return(album$id)
}
ggupload = function(token) {
albumID = get_or_create_album(token)
x = tempfile(fileext = '.pdf')
ggsave(filename=x)
p = last_plot()
title = ""
desc = ""
labels = names(p$labels)
if ("x" %in% labels && "y" %in% labels)
title = paste(p$labels$x,"vs",p$labels$y)
desc = title
if ("title" %in% labels)
title = p$labels$title
imgur_upload(file = x, album = albumID, title=title, description = desc, token = token)
}
This works as follows
> token = imgur_login()
> ggplot(dstat, aes(x=obs,y=tcp)) + geom_line() + theme_bw()
> ggupload(token)