This internal function facilitates creating a formatter that uses a specific device for rendering.
Usage
device_formatter(dev_open, dev_close = grDevices::dev.off())Arguments
- dev_open
The function that opens the device
- dev_close
The function closing the device. Usually this would be
grDevices::dev.off()
Examples
# Create a png formatter using the default png device
device_formatter(png)
#> function (...)
#> {
#> provided_args <- names(enquos(...))
#> dev_args <- fn_fmls_names(dev_open)
#> extra_args <- setdiff(provided_args, dev_args)
#> if (length(extra_args) != 0 && !"..." %in% dev_args) {
#> cli::cli_abort("Provided arguments does not match arguments in {.fun {dev_name}}")
#> }
#> init_dev <- function() {
#> output_file <- tempfile()
#> dev_open(filename = output_file, ...)
#> dev_id <- grDevices::dev.cur()
#> list(path = output_file, dev = dev_id)
#> }
#> close_dev <- function(info) {
#> grDevices::dev.set(info$dev)
#> grDevices::dev.off()
#> if (!file.exists(info$path)) {
#> return(NULL)
#> }
#> con <- file(info$path, "rb")
#> on.exit({
#> close(con)
#> unlink(info$path)
#> }, add = TRUE)
#> readBin(con, "raw", file.info(info$path)$size)
#> }
#> clean_dev <- function(info) {
#> grDevices::dev.set(info$dev)
#> grDevices::dev.off()
#> unlink(info$path)
#> }
#> with_dev <- function(x, info) {
#> promises::with_promise_domain(create_graphics_device_promise_domain(info$dev),
#> x)
#> }
#> structure(identity, init = init_dev, close = close_dev, clean = clean_dev,
#> with = with_dev, class = "device_formatter")
#> }
#> <bytecode: 0x5647afc06778>
#> <environment: 0x5647afc04420>
#> attr(,"class")
#> [1] "device_constructor"