How to flatten some PDF form fields but not all of them

Question

I am using C# and iTextSharp for PDFs. I have a PDF template that has form fields for information and also form fields for electronic signatures. I need to be able to have staff fill our part of the form, then in code, flatten that part (leaving the signature fields alone) and then I will be passing off the PDF to DocuSign's API to have the user sign the document electronically.

I have requirements that only the fields that should be editable by the user (signature) are form fields when they reach the DocuSign API. I have to flatten all the other fields before passing it to the DocuSign API (DocuSign automatically can Tag form fields for Signature).

Does anyone know how to do this? I have thought about getting the position of the signature fields, and after flattening the whole PDF adding the form fields back in with iTextSharp, but I feel that is a hack.

Answer 1

If you would like to flatten a specific field rather than the whole document then I believe you can use the following:

Stamper.FormFlattening = true;
Stamper.PartialFormFlattening("FieldName");

The only downside to this method is that you need to list every field that needs to be flattened. I think they are required to contain a value as well (i.e. you can't flatten a blank field).

Answer 2

Yes you can specify the names of the filed you want to update just take a look at the following example.

http://www.4guysfromrolla.com/articles/030211-1.aspx

Answer 3

Please see the following page from DocuSign's REST API guide as it has some good info on what you can do with the Adobe form fields and some special cases:

http://www.docusign.com/p/RESTAPIGuide/Content/REST%20API%20References/Document%20Parameters.htm

Answer 4

For XFA form you get

Partial form flattening is not supported with XFA forms.

exception if you use PartialFormFlattening.

To flat some fields I used

stamper.AcroFields.SetFieldProperty(fieldName, "setfflags", PdfFormField.FF_READ_ONLY, null);

make sure you use full fieldName (for instance for W-9 Name field use "topmostSubform[0].Page1[0].f1_1[0]" not "f1_1") otherwise it won't work.

I also tried remove XFA with

PdfDictionary acro =
   (PdfDictionary)PdfReader.GetPdfObject(
           pdfReader.Catalog.Get(PdfName.ACROFORM));
                acro.Remove(PdfName.XFA);

as it described here but I got the same exception.