Error: unable to find an inherited method for function ‘extent’ for signature ‘x = "ggplot2::ggplot"’

[achubaty]

Trying to render the plotting vignette, specifically the Plot(ggQbj) line in:

quickPlot/vignettes/iii-plotting.Rmd

Lines 134 to 140 in 99bfafa

	if (requireNamespace("ggplot2")) {
	ggObj <- data.frame(x = stats::rnorm(1e3)) |>
	ggplot2::ggplot(ggplot2::aes(x = x)) +
	ggplot2::geom_histogram()
	clearPlot()
	Plot(caribou, axes = "L", new = TRUE)
	Plot(ggObj)

I'm hitting the extent error in .makeViewports because of hasMethod("extent", is(obj)[1]):

quickPlot/R/plotting-helpers.R

Lines 2292 to 2299 in 99bfafa

	# if the object has an extent method
	if (hasMethod("extent", is(obj)[1]) && !is.list(obj)) {
	# list has an extent method, but too general
	out <- extent(obj)
	} else {
	# for non spatial objects
	out <- list(xmin = 0, xmax = 2, ymin = 0, ymax = 2)
	}

this is likely the correct thing to check, but there is a ggplot method:

> showMethods("extent")
Function: extent (package quickPlot)
x="ANY"
x="ggplot2::ggplot"
    (inherited from: x="ANY")

this suggests that the actual problem is the incorrect use of methods here: a single 'ANY' method is defined that checks the signature of the object inside the method, rather than defining methods for each allowed signature and letting R deal with method dispatch:

quickPlot/R/plotting-helpers.R

Lines 2795 to 2826 in 99bfafa

	setMethod(
	"extent",
	signature("ANY"),
	definition = function(x, ...) {
	.ExtentToList(x)
	}
	)
	.ExtentToList <- function(x) {
	if (!is(x, "list")) {
	x <- if (inherits(x, "sf")) {
	x <- as.list(sf::st_bbox(x))
	} else { # if (isGridded(x) || inherits(x, "Spatial") || isSpat(x) ||
	# is(x, "SpatExtent") || is(x, "Extent")) {
	if (!is(x, "SpatExtent")) {
	if (isSpat(x) || isSpatial(x))
	x <- terra::ext(x)
	else {
	if (!requireNamespace("raster", quietly = TRUE)) {
	stop("Need to install.packages('raster')")
	}
	x <- raster::extent(x)
	}
	}
	list(
	xmin = terra::xmin(x), xmax = terra::xmax(x),
	ymin = terra::ymin(x), ymax = terra::ymax(x)
	)
	}
	}
	x
	}

[achubaty]

also failing in:

Failure (test-Plot.R:217:5): Plot 1 is not error-free
Expected `Plot(ggplot87654)` to run without any errors.
i Actually got a <simpleError> with text:
  unable to find an inherited method for function 'extent' for signature 'x = "ggplot2::ggplot"'

[achubaty]

resolved in ggplot2_v4 branch