Q: CombinePDF vs Prawn for PDF manipulation in Ruby?

CombinePDF is best for merging, numbering, and watermarking existing PDFs with no dependencies, while Prawn excels at generating new PDFs from scratch but requires more code for modifications.

Q: How to add a logo watermark to every page of a PDF?

Load the stamp PDF, extract its first page, then iterate through the target PDF's pages and use `page << logo_page`; for example, `pdf.pages.each { |p| p << logo }` overlays the content.

Q: Does CombinePDF support encrypted PDF files?

Support is limited; it may fail silently or raise an `EncryptionError` with `raise_on_encrypted: true`. Not reliable for handling password-protected or heavily encrypted PDFs.

Q: Is CombinePDF still maintained and safe to use?

No, the project is unmaintained as per the README, with the author seeking maintainers. This means potential security issues or bugs might not be fixed, so use with caution in production.

Q: What happens to PDF forms when using CombinePDF?

Form data can be lost or unified during merging, as forms are global objects not page-specific. The README admits this is a known limitation with no complete fix.

Question 1

How to merge PDF files in Ruby without installing external tools?

Accepted Answer

Use CombinePDF's `load` method to read files and the `<<` operator to combine them; for example, `(CombinePDF.load('a.pdf') << CombinePDF.load('b.pdf')).save('merged.pdf')` does it in one line.

Question 2

CombinePDF vs Prawn for PDF manipulation in Ruby?

Accepted Answer

CombinePDF is best for merging, numbering, and watermarking existing PDFs with no dependencies, while Prawn excels at generating new PDFs from scratch but requires more code for modifications.

Question 3

How to add a logo watermark to every page of a PDF?

Accepted Answer

Load the stamp PDF, extract its first page, then iterate through the target PDF's pages and use `page << logo_page`; for example, `pdf.pages.each { |p| p << logo }` overlays the content.

Question 4

Does CombinePDF support encrypted PDF files?

Accepted Answer

Support is limited; it may fail silently or raise an `EncryptionError` with `raise_on_encrypted: true`. Not reliable for handling password-protected or heavily encrypted PDFs.

Question 5

Is CombinePDF still maintained and safe to use?

Accepted Answer

No, the project is unmaintained as per the README, with the author seeking maintainers. This means potential security issues or bugs might not be fixed, so use with caution in production.

Question 6

What happens to PDF forms when using CombinePDF?

Accepted Answer

Form data can be lost or unified during merging, as forms are global objects not page-specific. The README admits this is a known limitation with no complete fix.

CombinePDF

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