if TRUE, extract font-data for each box. Be careful, this
requires a very recent version of poppler and will error otherwise.
Details
The pdf_text function renders all textboxes on a text canvas
and returns a character vector of equal length to the number of pages in the
PDF file. On the other hand, pdf_data is more low level and
returns one data frame per page, containing one row for each textbox in the PDF.
Note that pdf_data requires a recent version of libpoppler
which might not be available on all Linux systems.
When using pdf_data in R packages, condition use on
poppler_config()$has_pdf_data which shows if this function can be
used on the current system. For Ubuntu 16.04 (Xenial) and 18.04 (Bionic)
you can use the PPA
with backports of Poppler 0.74.0.
Poppler is pretty verbose when encountering minor errors in PDF files,
in especially pdf_text. These messages are usually safe
to ignore, use suppressMessages to hide them altogether.
# Just a random pdf filepdf_file <- file.path(R.home("doc"), "NEWS.pdf")
info <- pdf_info(pdf_file)
text <- pdf_text(pdf_file)
fonts <- pdf_fonts(pdf_file)
files <- pdf_attachments(pdf_file)