DLI Implementation and Reference Guide - Datalogics

A.160 DLI Reference Guide
dlpdfsignaturesetdatacallback
(DLPDFSIGNATURE *signature, void (*dataCallback)(char *,
int))
Return Value: void
Concepts and Facilities: Guide to the DL Pager Composition System
Description
Parameters
Return Value
This is an optional call for clients using PKCS
#7 certificates. A callback function is supplied
for the signature.
• DLPDFSIGNATURE *signature: signature
with which PKCS #7 certificate will be
associated
• void (*dataCallback)(char *,
int): callback function, called during the
dlpdfdocwritepdf function call; see
Technical Notes below.
void
Exceptions
Header
Related Methods
Availability
dli.h
dlpdfsignaturesetpkcs7cert
dlpdfdocwritepdf
All DLI-supported platforms.
Technical Notes
1 The callback is called during the dlpdfdocwritepdf function with binary
information from the PDF file. This information will be in sequential pieces, and
may be used to generate the PDF document hash value. The information is
supplied as binary values in the character buffer; the length to read is supplied as
the second parameter.
• A length of 0 (zero) passed in the callback function indicates that no further data is
to be read, and the hash may be finalized.