chrome_print: Print a web page to PDF or capture a screenshot using the...
In pagedown: Paginate the HTML Output of R Markdown with CSS for Print

View source: R/chrome.R

chrome_print

R Documentation

Print a web page to PDF or capture a screenshot using the headless Chrome

Description

Print an HTML page to PDF or capture a PNG/JPEG screenshot through the Chrome DevTools Protocol. Google Chrome or Microsoft Edge (or Chromium on Linux) must be installed prior to using this function.

Usage

chrome_print(
  input,
  output = xfun::with_ext(input, format),
  wait = 2,
  browser = "google-chrome",
  format = c("pdf", "png", "jpeg"),
  options = list(),
  selector = "body",
  box_model = c("border", "content", "margin", "padding"),
  scale = 1,
  work_dir = tempfile(),
  timeout = 30,
  extra_args = c("--disable-gpu"),
  verbose = 0,
  async = FALSE,
  outline = gs_available(),
  encoding
)

Arguments

`input`	A URL or local file path to an HTML page, or a path to a local file that can be rendered to HTML via `rmarkdown::render()` (e.g., an R Markdown document or an R script). If the `input` is to be rendered via `rmarkdown::render()` and you need to pass any arguments to it, you can pass the whole `render()` call to `chrome_print()`, e.g., if you need to use the `params` argument: `pagedown::chrome_print(rmarkdown::render('input.Rmd', params = list(foo = 1:10)))`. This is because `render()` returns the HTML file, which can be passed to `chrome_print()`.
`output`	The output filename. For a local web page ‘foo/bar.html’, the default PDF output is ‘foo/bar.pdf’; for a remote URL ‘https://www.example.org/foo/bar.html’, the default output will be ‘bar.pdf’ under the current working directory. The same rules apply for screenshots.
`wait`	The number of seconds to wait for the page to load before printing (in certain cases, the page may not be immediately ready for printing, especially there are JavaScript applications on the page, so you may need to wait for a longer time).
`browser`	Path to Google Chrome, Microsoft Edge or Chromium. This function will try to find it automatically via `find_chrome()` if the path is not explicitly provided and the environment variable `PAGEDOWN_CHROME` is not set.
`format`	The output format.
`options`	A list of page options. See `https://chromedevtools.github.io/devtools-protocol/tot/Page#method-printToPDF` for the full list of options for PDF output, and `https://chromedevtools.github.io/devtools-protocol/tot/Page#method-captureScreenshot` for options for screenshots. Note that for PDF output, we have changed the defaults of `printBackground` (`TRUE`), `preferCSSPageSize` (`TRUE`) and when available `transferMode` (`ReturnAsStream`) in this function.
`selector`	A CSS selector used when capturing a screenshot.
`box_model`	The CSS box model used when capturing a screenshot.
`scale`	The scale factor used for screenshot.
`work_dir`	Name of headless Chrome working directory. If the default temporary directory doesn't work, you may try to use a subdirectory of your home directory.
`timeout`	The number of seconds before canceling the document generation. Use a larger value if the document takes longer to build.
`extra_args`	Extra command-line arguments to be passed to Chrome.
`verbose`	Level of verbosity: `0` means no messages; `1` means to print out some auxiliary messages (e.g., parameters for capturing screenshots); `2` (or `TRUE`) means all messages, including those from the Chrome processes and WebSocket connections.
`async`	Execute `chrome_print()` asynchronously? If `TRUE`, `chrome_print()` returns a `promise` value (the promises package has to be installed in this case).
`outline`	If not `FALSE`, `chrome_print()` will add the bookmarks to the generated `pdf` file, based on the table of contents informations. This feature is only available for output formats based on `html_paged`. It is enabled by default, as long as the Ghostscript executable can be detected by `find_gs_cmd`.
`encoding`	Not used. This argument is required by RStudio IDE.