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Compare PDF Files in Two Directories

Source: R/pdf.R
compare_pdf_dirs.Rd

Compare every PDF file in a baseline directory with the PDF file of the same relative path in a current directory, page by page, using compare_pdfs(). Useful for re-running a full set of outputs (for example all tables, listings and figures of a study) after an R or package upgrade and checking that nothing changed visually.

Usage

compare_pdf_dirs(
  baseline_dir,
  current_dir,
  pattern = "\\.pdf$",
  recursive = FALSE,
  pages = NULL,
  dpi = 150,
  diff_dir = NULL,
  parallel = FALSE,
  ...
)

Arguments

baseline_dir

Path to the directory containing the baseline PDFs.

current_dir

Path to the directory containing the current PDFs.

pattern

Regular expression matched (case-insensitively) against file names. Default matches .pdf files.

recursive

Logical; if TRUE, search subdirectories recursively. Default is FALSE.

pages, dpi

Passed to compare_pdfs() for every file.

diff_dir

Directory to save diff images and rendered pages. Each PDF gets its own subdirectory, named after its relative path. If NULL (default), no diff images are created.

parallel

Logical; if TRUE, compare the pages of each file in parallel. See compare_images_batch() for details.

...

Additional arguments passed to compare_pdfs() (e.g. threshold, antialiasing, ignore_regions, fail_on_layout).

Value

A tibble (if available) or data.frame with class odiffr_batch, combining the results for all files (in baseline file order) with a sequential pair_id, the columns of compare_pdfs() (including page) and a trailing file column giving the relative path of the PDF.

Details

The baseline directory is the source of truth, as in compare_image_dirs():

  • A PDF missing from current_dir triggers a warning and is reported as a single row with match = FALSE, reason = "missing", page = NA and the error "File not found in current_dir".

  • A PDF that cannot be read (e.g. corrupt or password-protected) is reported as a single row with reason = "error", page = NA and the error message, instead of aborting the whole comparison.

  • PDFs that exist only in current_dir are not compared, but a message notes how many were found.

Differences in page counts are reported per file as described in compare_pdfs().

An error is raised if baseline_dir contains no files matching pattern.

See also

compare_pdfs(), compare_image_dirs(), batch_report()

Examples

if (FALSE) { # \dontrun{
res <- compare_pdf_dirs("outputs-r4.3/", "outputs-r4.4/",
                        diff_dir = "pdf-diffs", recursive = TRUE)
summary(res)
unique(res$file[!res$match])
batch_report(res, output_file = "pdf-diffs/report.html")
} # }