How do you combine PDFs in ruby?

Question

This was asked in 2008. Hopefully there's a better answer now.

How can you combine PDFs in ruby?

I'm using the pdf-stamper gem to fill out a form in a PDF. I'd like to take n PDFs, fill out a form in each of them, and save the result as an n-page document.

Can you do this with a native library like prawn? Can you do this with rjb and iText? pdf-stamper is a wrapper on iText.

I'd like to avoid using two libraries (i.e. pdftk and iText), if possible.

Answer 1

As of 2013 you can use Prawn to merge pdfs. Gist: https://gist.github.com/4512859

class PdfMerger

  def merge(pdf_paths, destination)

    first_pdf_path = pdf_paths.delete_at(0)

    Prawn::Document.generate(destination, :template => first_pdf_path) do |pdf|

      pdf_paths.each do |pdf_path|
        pdf.go_to_page(pdf.page_count)

        template_page_count = count_pdf_pages(pdf_path)
        (1..template_page_count).each do |template_page_number|
          pdf.start_new_page(:template => pdf_path, :template_page => template_page_number)
        end
      end

    end

  end

  private

  def count_pdf_pages(pdf_file_path)
    pdf = Prawn::Document.new(:template => pdf_file_path)
    pdf.page_count
  end

end