Take a snapshot of an R Markdown document

This function can handle both static Rmd documents and Rmd documents with runtime: shiny.

Usage

rmdshot(
  doc,
  file = "webshot.png",
  ...,
  delay = NULL,
  rmd_args = list(),
  port = getOption("shiny.port"),
  envvars = NULL
)

Arguments

doc: The path to a Rmd document.
file: A vector of names of output files. Should end with an image file type (.png, .jpg, .jpeg, or .webp) or .pdf. If several screenshots have to be taken and only one filename is provided, then the function appends the index number of the screenshot to the file name. For PDF output, it is just like printing the page to PDF in a browser; selector, cliprect, expand, and zoom will not be used for PDFs.
...: Other arguments to pass on to webshot().
delay: Time to wait before taking screenshot, in seconds. Sometimes a longer delay is needed for all assets to display properly. If NULL (the default), then it will use 0.2 seconds for static Rmd documents, and 3 seconds for Rmd documents with runtime:shiny.
rmd_args: A list of additional arguments to pass to either rmarkdown::render() (for static Rmd documents) or rmarkdown::run() (for Rmd documents with runtime:shiny).
port: Port that Shiny will listen on.
envvars: A named character vector or named list of environment variables and values to set for the Shiny app's R process. These will be unset after the process exits. This can be used to pass configuration information to a Shiny app.

Value

Invisibly returns the normalized path to all screenshots taken. The character vector will have a class of "webshot".

Examples

if (interactive()) {
  # R Markdown file
  input_file <- system.file("examples/knitr-minimal.Rmd", package = "knitr")
  rmdshot(input_file, "minimal_rmd.png")

  # Shiny R Markdown file
  input_file <- system.file("examples/shiny.Rmd", package = "webshot")
  rmdshot(input_file, "shiny_rmd.png", delay = 5)
}