I have a case in which I grab the attachments through service in nintex workflow, and get the xml data, what I want now is to fill this data to the attachment control in nintex, so the user can add more attachments or delete from the existing ones, is that possible in nintex workflow??
Attachments isn't a site column and are treated as documents via SharePoint so its not available. When you look at the site column for attachments it is a yes or no trigger only.
So using the add attachment method is kinda the only way :-).