New features

• get_bookmarks_pdftools() gets pdf bookmark information using pdftools::pdf_toc() (#30).
  Note though due to poppler library limitations it can't return page numbers that correspond to each bookmark.
  Hence get_bookmarks() will try to use the following helper functions in the following order:

  1. get_bookmarks_pdftk()
  2. get_bookmarks_pdftools()

Bug fixes and minor improvements

• We can again disable old bookmarks when setting new bookmarks
  in set_bookmarks_gs() for the newest versions of ghostscript (#59).
  The new approach means we could remove some GPLv3 code and have relicensed the package under the MIT license.
• Improved support for reading/writing Unicode values in non-Unicode locales (#57).
• get_bookmarks() and get_bookmarks_pdftk() no longer returns its data frame value invisibly.

• Unit tests have been adjusted to prevent a CRAN R CMD check ERROR on
  an M1 Mac machine running macOS 14 (#58).

Bug fixes and minor improvements

• set_docinfo_exiftool() should now losslessly write all legal datetimes (#55).
  set_docinfo()'s priority order has been updated to the following:

  1. set_docinfo_exiftool()
  2. set_docinfo_gs()
  3. set_docinfo_pdftk()

• Unit tests have been adjusted to prevent CRAN R CMD check ERRORs on certain CRAN platforms
  that don't have ghostscript installed or are ran in a non-Unicode locale (#56).

Initial features

• 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.

• get_bookmarks() returns a data frame with pdf bookmarks information.
  get_bookmarks() will try to use the following helper functions in the following order:

  1. get_bookmarks_pdftk() which wraps pdftk command-line tool

• set_bookmarks() sets (replaces) pdf bookmarks information.
  set_bookmarks() will try to use the following helper functions in the following order:

  1. set_bookmarks_gs() which wraps ghostscript command-line tool
  2. set_bookmarks_pdftk() which wraps pdftk command-line tool

• docinfo() provides an {R6} object to represent pdf documentation info entries.

• as_docinfo() can coerce objects into docinfo() objects.
  In particular there is an as_docinfo.xmp() method to coerce xmp() objects.

• get_docinfo() reads in pdf documentation info entries from pdf file(s).
  get_docinfo() will try to use the following helper functions in the following order:

  1. get_docinfo_pdftk() which wraps pdftk command-line tool
  2. get_docinfo_exiftool() which wraps exiftool command-line tool
  3. get_docinfo_pdftools() which wraps pdftools::pdf_info()

• set_docinfo() sets pdf documentation info entries to a pdf file.
  set_docinfo() will try to use the following helper functions in the following order:

  1. set_docinfo_gs() which wraps ghostscript command-line tool
  2. set_docinfo_pdftk() which wraps pdftk command-line tool
  3. set_docinfo_exiftool() which wraps exiftool command-line tool

• xmp() provides an {R6} object to represent xmp metadata.

  • as_lang_alt() supports "language alternative" XMP tags.

• as_xmp() can coerce objects into xmp() objects.
  In particular there is an as_xmp.docinfo() method to coerce docinfo() objects.

• get_xmp() reads in xmp metadata from media file(s).
  get_xmp() will try to use the following helper functions in the following order:

  1. get_xmp_exiftool() which wraps exiftool command-line tool

• set_xmp() sets xmp metadata in media file(s).
  set_xmp() will try to use the following helper functions in the following order:

  1. set_xmp_exiftool() which wraps exiftool command-line tool

• cat_pages() concatenates (pdf) file(s) into a single output pdf.
  cat_pages() will try to use the following helper functions in the following order:

  1. cat_pages_qpdf() which wraps qpdf::pdf_combine()
  2. cat_pages_pdftk() which wraps pdftk command-line tool
  3. cat_pages_gs() which wraps ghostscript command-line tool

• n_pages() returns the number of pages in the (pdf) file(s).
  n_pages() will try to use the following helper functions in the following order:

  1. n_pages_qpdf() which wraps qpdf::pdf_length()
  2. n_pages_exiftool() which wraps exiftool command-line tool
  3. n_pages_pdftk() which wraps pdftk command-line tool
  4. n_pages_gs() which wraps ghostscript command-line tool

• The following functions detect support for various higher-level features:

  • supports_get_bookmarks()
  • supports_set_bookmarks()
  • supports_get_docinfo()
  • supports_set_docinfo()
  • supports_get_xmp()
  • supports_set_xmp()
  • supports_n_pages()

• The following functions detect support for various command-line tools needed for some
  lower-level helper functions:

  • supports_exiftool() detects support for exiftool
  • supports_gs() detects support for ghostscript
  • supports_pdftk() detects support for pdftk

• enable_feature_message() returns a character vector with the
  information needed to install the requested feature.
  Formatted for use with rlang::abort(), rlang::warn(), or rlang::inform().

• The spdx_licenses data set contains the SPDX License List.