Thank you Patrick for reply!
In my scenario user fills in form, signs it digitally and clicks button 'Send'. Then webservice is invoked,
some of data is saved to database (from dataset) and at this moment I want to modify one of fields in my
form (saved on SP and from webservice level!). Promoted fields are marked as read only and I don't wan't
them to be changed by user manually.
Solution from stackoverflow works fine for me but is slow (get forms contents, parse, modify, upload).
I'm searching for something like this: open SP site -> open form library -> open form -> edit SP field
(automatically update infopath form contents). I have tried to edit in this way, but it doesn't work for fields
connected with Infopath form.
regards Jarecki