Creating PDF/3-A compliant PDF and attaching ZUGFeRD invoice in Python

Attach ZUGFeRD to PDF

We recommend following steps to attach ZUGFeRD to PDF:

  1. Import the Aspose.PDF library and give it an alias of ap for convenience.
  2. Define the path to the directory where the input and output PDF files are located.
  3. Define the path to the PDF file that will be processed.
  4. Load the PDF file from the path variable and create a Document object.
  5. Create a FileSpecification object for the XML file that contains the invoice metadata. Use the path variable and a description string to create the FileSpecification object.
  6. Set the mime_type and the af_relationship properties of the FileSpecification object to text/xml and ALTERNATIVE, respectively.
  7. Add the fileSpecification object to the document object’s embedded files collection. This attaches the XML file to the PDF document as an invoice metadata file.
  8. Convert the PDF document to the PDF/A-3A format. Use the path to log file, the PdfFormat.PDF_A_3A enumeration, and the ConvertErrorAction.DELETE enumeration to convert the document object.
  9. Save the PDF document with the attached ZUGFeRD.
import sys
import os
import aspose.pdf as ap

def attach_invoice_zugferd_format(infile, invoice, outfile):
    document = ap.Document(infile)

    # Create a FileSpecification object for the XML file that contains the invoice metadata
    description = "Invoice metadata conforming to ZUGFeRD standard"
    file_specification = ap.FileSpecification(invoice, description)

    # Set the MIME type and the AFRelationship properties of the embedded file
    file_specification.mime_type = "text/xml"
    file_specification.af_relationship = ap.AFRelationship.ALTERNATIVE

    # Add the embedded file to the PDF document's embedded files collection
    document.embedded_files.add("factur", file_specification)

    # Convert the PDF document to the PDF/A-3A format
    log_path = outfile.replace(".pdf", "_log.xml")
    document.convert(log_path, ap.PdfFormat.PDF_A_3A, ap.ConvertErrorAction.DELETE)
    document.save(outfile)