问Plumber R渲染svg文件

EN

library(plumber)

device_size <- function() {
  h_ <- 7
  w_ <- 7
  list(
    h = function() h_,
    w = function() w_,
    set_h = function(h) if (!is.null(h)) {h_ <<- as.numeric(h)},
    set_w = function(w) if (!is.null(w)) {w_ <<- as.numeric(w)}
  )
}

output_size <- device_size()

serializer_dynamic_svg <- function(..., type = "image/svg+xml") {
  serializer_device(
    type = type,
    dev_on = function(filename) {
      grDevices::svg(filename,
                     width = output_size$w(),
                     height = output_size$h())
    }
  )
}
register_serializer("svg", serializer_dynamic_svg)

#* @filter dynamic_size
function(req) {
  if (req$PATH_INFO == "/plot") {
    output_size$set_w(req$args$width)
    output_size$set_h(req$args$height)
  }
  plumber::forward()
}

#* @get /plot
#* @param width
#* @param height
#* @serializer svg
function() {
  plot(iris)
}