使用 pagedown::chrome_print（R 包）将页码添加到 pdf？

Question

I am using pagedown::chrome_print() to convert slidy presentations created with Rmarkdown to pdf -- it does a better job than saving as PDF from Chrome. However, despite studying the help file, I cannot figure out how to add page numbers. Is there a way to do this?

(Note that pagedown here refers to the R package, not the JavaScript markdown previewer.)

Answer 1

Sorry if the help page is not clear on this point.

It is possible to pass header/footer options to Chrome using pagedown::chrome_print() .

These options are the ones defined by the Chrome DevTools Protocol for the Page.printToPDF method .

You can customise the header and the footer with an HTML template. Chrome also offers the following values: date , title , url , pageNumber and totalPages .

Following the explanations on this help page, here is an example to print the page numbers:

library(htmltools)

footer <- div(
  style = "font-size: 8pt; text-align: right; width: 100%; padding-right: 12pt;", 
  span(class = "pageNumber"), "/", span(class = "totalPages")
)

pagedown::chrome_print(
  "slidy.Rmd", 
  options = list(
    landscape = TRUE, 
    displayHeaderFooter = TRUE, 
    footerTemplate = format(footer, indent = FALSE),
    marginTop = 0,
    marginBottom = 0.4
  )
)

Answer 2

I got it to work with a custom CSS file. I created a file called custom.css and included in that file was

@page  {
  @bottom-right {
    content: counter(page);
  }
}

Then I used that along with the other pagedown defaults with a header like this

title: "My Report"
output:
  pagedown::html_paged: 
    css: ["custom.css", "default-fonts", "default"]