Open a PDF document — pdf_doc

Loads a PDF from disk or from an in-memory byte buffer. The returned pdfium_doc carries an external pointer to a PDFium FPDF_DOCUMENT handle along with a finalizer that calls FPDF_CloseDocument() when the R object is garbage-collected. Call pdf_doc_close() explicitly when you need deterministic release.

Usage

pdf_doc_open(path = NULL, source = NULL, password = NULL, readwrite = FALSE)

Arguments

path: Character scalar. Path to a PDF file. The file must exist and be readable. Mutually exclusive with source.
source: Raw vector containing the PDF byte stream. PDFium keeps an internal reference to the bytes for the document's lifetime, so the wrapper makes its own copy on the C++ side and releases it when the pdfium_doc is garbage-collected. Mutually exclusive with path.
password: Optional password for encrypted PDFs. NULL (the default) passes no password to PDFium.
readwrite: Logical. If TRUE, the document is opened in read-write mode and every mutator function (pdf_save(), pdf_page_set_rotation(), the pdf_*_set_*() family, annotation authoring, form filling, …) will accept it. Defaults FALSE — a read-only handle that refuses mutations with a clear error message. See ADR-012 in dev/decisions/. PDFium itself has no read/write distinction; the flag is the R wrapper's safety net against accidental edits inside long pipelines.

Value

A pdfium_doc object.

Details

Two input forms are supported. Pass path to load from disk (via PDFium's FPDF_LoadDocument), or pass source for an in-memory raw vector (via FPDF_LoadMemDocument64). The in-memory path is useful for documents downloaded via httr2::resp_body_raw(), curl::curl_fetch_memory(), or read with readBin() straight into RAM. Exactly one of path or source must be provided.

Examples

fixture <- system.file("extdata", "fixtures", "minimal.pdf",
  package = "pdfium"
)
if (nzchar(fixture)) {
  doc <- pdf_doc_open(fixture)
  pdf_page_count(doc)
  pdf_doc_close(doc)
}

# Round-trip via raw bytes - useful for downloaded PDFs.
if (nzchar(fixture)) {
  bytes <- readBin(fixture, "raw", file.info(fixture)$size)
  doc <- pdf_doc_open(source = bytes)
  pdf_page_count(doc)
  pdf_doc_close(doc)
}