cat_bookmarks {xmpdf}

Concatenate pdf bookmarks

Description

cat_bookmarks() concatenates a list of bookmarks into a single bookmarks data frame while updating the page numbers. Useful if wanting to concatenate multiple pdf files together and would like to preserve the bookmarks information.

Usage

cat_bookmarks(
  l,
  method = c("flat", "filename", "title"),
  open = NA,
  color = NA_character_,
  fontface = NA_character_
)

Arguments

l

A list of bookmark data frames as returned by get_bookmarks(). Each data frame should have a "total_pages" attribute. If method = "filename" each data frame should have a "filename" attribute. If method = "title" each data frame should have a "title" attribute.

method

If "flat" simply concatenate the bookmarks while updating page numbers. If "filename" place each file's bookmarks a level under a new bookmark matching the (base)name of the filename and then concatenate the bookmarks while updating page numbers. If "title" place each file's bookmarks a level under a new bookmark matching the title of the file and then concatenate the bookmarks while updating page numbers.

open

If method = "filename" or method = "title" a logical for whether the new top level bookmarks should start open? If missing will default to open. Note some pdf viewers quietly ignore the initially open/closed feature.

color

If method = "filename" or method = "title" the color of the new top level bookmarks. If NA_character_ will be unset (presumably defaults to "black"). Note many pdf viewers quietly ignore this feature.

fontface

If method = "filename" or method = "title" should the fontface of the new top level bookmarks. If NA_character_ or NA_integer_ will be unset (defaults to "plain"). "plain" or 1 is plain, "bold" or 2 is bold, "italic" or 3 is italic, Note many pdf viewers quietly ignore this feature.

Value

A data frame of bookmark data (as suitable for use with set_bookmarks()). A "total_pages" attribute will be set for the theoretical total pages of the concatenated document represented by the concatenated bookmarks.

See Also

get_bookmarks() and set_bookmarks() for setting bookmarks. cat_pages() for concatenating pdf files together.

Examples

if (supports_get_bookmarks() &&
    supports_set_bookmarks() &&
    supports_pdftk() &&
    require("grid", quietly = TRUE)) {
 # Create two different two-page pdf files
 make_pdf <- function(f, title) {
   pdf(f, onefile = TRUE, title = title)
   grid.text(paste(title, "Page 1"))
   grid.newpage()
   grid.text(paste(title, "Page 2"))
   invisible(dev.off())
 }
 f1 <- tempfile(fileext = "_doc1.pdf")
 on.exit(unlink(f1))
 make_pdf(f1, "Document 1")

 f2 <- tempfile(fileext = "_doc2.pdf")
 on.exit(unlink(f2))
 make_pdf(f2, "Document 2")

 # Add bookmarks to the two two-page pdf files
 bookmarks <- data.frame(title = c("Page 1", "Page 2"),
                         page = c(1L, 2L))
 set_bookmarks(bookmarks, f1)
 set_bookmarks(bookmarks, f2)
 l <- get_bookmarks(c(f1, f2))
 print(l)

 bm <- cat_bookmarks(l, method = "flat")
 cat('\nmethod = "flat":\n')
 print(bm)

 bm <- cat_bookmarks(l, method = "filename")
 cat('\nmethod = "filename":\n')
 print(bm)

 bm <- cat_bookmarks(l, method = "title")
 cat('\nmethod = "title":\n')
 print(bm)

 # `cat_bookmarks()` is useful for setting concatenated pdf files
 # created with `cat_pages()`
 if (supports_cat_pages()) {
    fc <- tempfile(fileext = "_cat.pdf")
    on.exit(unlink(fc))
    cat_pages(c(f1, f2), fc)
    set_bookmarks(bm, fc)
    unlink(fc)
 }

 unlink(f1)
 unlink(f2)
}