Create PDF from Selected Pages

PDF files may have tens or hundreds of pages depending on the nature of their content. An effective way to handle specific information from these files is to gather it in a separate file. Robomotion's PDF nodes enable users to extract any possible combination of pages and save them in different files for further manipulation.

What Create PDF from Selected Pages can do

• Build defaults (Core.Programming.Function) — seeds msg.default_pdf (fixtures/sample.pdf) and msg.default_dest (fixtures/output) from $Home$.
• Input Dialog (Core.Dialog.InputBox) titled Create new PDF from selected PDF pages, prompt Select the PDF to extract pages from:, default msg.default_pdf → msg.pdf_path.
• Input Dialog with prompt Page number(s) e.g. 1,3,5-7:, default 1,3,5-7 → msg.pages_text.
• Input Dialog with prompt Select a folder to save the new PDF file..., default msg.default_dest → msg.destination_folder.
• Validate and parse (Core.Programming.Function, outputs: 2) — checks that msg.pdf_path ends in .pdf, expands msg.pages_text (singles + a-b ranges) into a deduped, sorted msg.selected_pages array, and seeds msg.pages_dir, msg.candidate_path, msg.suffix_idx = 0; invalid input short-circuits to Core.Flow.Stop.
• Prepare dirs (Core.FileSystem.Create on msg.destination_folder, then Core.FileSystem.Delete + Core.FileSystem.Create on msg.pages_dir, all continueOnError).
• Split per page (Robomotion.PDFBox.Split, optPerPage: 1, prefix p) — writes one PDF per source page into msg.pages_dir.
• List pages (Core.FileSystem.List, ascending) → msg.page_files, then pick selected paths (Core.Programming.Function, outputs: 2) — maps msg.selected_pages to the ascending file list into msg.picked_paths; empty selection goes to Core.Flow.Stop.
• Suffix loop (Core.Flow.Label + Core.FileSystem.PathExists on msg.candidate_path + Core.Programming.Function, outputs: 2) — if the candidate exists, bump msg.suffix_idx and retry (NewPDFfile_2.pdf, _3, ...); otherwise commit to msg.output_path.
• Merge selected (Robomotion.PDFBox.Merge) — joins msg.picked_paths into msg.output_path, then Core.FileSystem.Delete the pages scratch dir.
• Build done text (Core.Programming.Function) sets msg.dialog_text = 'The new file has been saved in: ' + msg.output_path, then a Message Dialog (Core.Dialog.MessageBox, optType: info) titled Done! shows it and the flow stops.

Behind the scenes

• The page-selection grammar (1,3,5-7 — mixed singles and ranges) is expanded inside the Function node: comma split, \d+-\d+ regex, dedupe, sort ascending. Pages outside the document range are silently dropped when mapping into msg.picked_paths.
• Suffix handling is explicit: the loop tests Core.FileSystem.PathExists on NewPDFfile.pdf, then NewPDFfile_2.pdf, NewPDFfile_3.pdf, ... so an existing output is never overwritten.
• Split-then-merge (one PDF per page, then merge the chosen subset) is used instead of a single range-extract call so arbitrary non-contiguous selections (1,3,5-7) work uniformly.
• Scratch pages under msg.pages_dir are cleared both before the split (stale run) and after the merge (cleanup).