Should plot with no layers add geom_blank() ?

[hadley]

Instead of current (not very useful behaviour)

[wch]

I think this would be useful in Shiny apps, where layers are added in response to some user input. Right now, if no layers are added, you'd need to do an explicit check for that, and then add geom_blank(). If this automatically happens, then that's less work for the developer, and there's not really any drawbacks that I can think of.

This would happen in the build phase, right?

[hadley]

Yeah, I'd just change:

if (length(plot$layers) == 0) stop("No layers in plot", call. = FALSE)

to

if (length(plot$layers) == 0) {
  plot <- plot + geom_blank()
}

[hadley]

Fixed in 1ab70de