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.

Answer 1

Via iText, this will work... though you should flatten the forms before you merge them to avoid field name conflicts. That or rename the fields one page at a time.

Within PDF, fields with the same name share a value. This is usually not the desired behavior, though it comes in handy from time to time.

Something along the lines of (in java):

PdfCopy mergedPDF = new PdfCopy( new Document(), new FileOutputStream( outPath );

for (String path : paths ) {
  PdfReader reader = new PdfReader( path );
  ByteArrayOutputStream curFormOut = new ByteArrayOutputStream();
  PdfStamper stamper = new PdfStamper( reader, curFormOut );

  stamper.setField( name, value ); // ad nauseum

  stamper.setFlattening(true); // flattening setting only takes effect during close()
  stamper.close();

  byte curFormBytes = curFormOut.toByteArray();
  PdfReader combineMe = new PdfReader( curFormBytes );

  int pages = combineMe .getNumberOfPages();
  for (int i = 1; i <= pages; ++i) { // "1" is the first page
    mergedForms.addPage( mergedForms.getImportedPage( combineMe, i );
  }
}

mergedForms.close();