THPDFHeadlessDocument.SaveFDFDifferencesToFile

Applies one FDF Differences payload as a cumulative append to the explicitly selected complete PDF base revision and writes the result file

function SaveFDFDifferencesToFile(const FileName: string;
  const Bytes: SysUtils.TBytes; BaseBytes: Int64; const BaseSHA256: AnsiString;
  const Selection: THPDFFDFChildSelections;
  const Options: THPDFFDFPackageOptions): THPDFHeadlessFDFDifferencesResult;

BaseBytes is the exact byte length of the selected base revision and BaseSHA256 is its hexadecimal SHA-256; the loaded document must still be byte-identical to that base when the append is published

Bytes carries the decoded Differences stream, for example from THPDFFDFPackage.DecodeDifferences; Selection and Options reuse the embedded-FDF package selection and limit controls

Result

The method returns THPDFHeadlessFDFDifferencesResult with base, prior-append, total-append and added byte counts plus an exact no-op flag

An equivalent repeated apply preserves the exact current PDF bytes and reports NoOp as True with zero added bytes

Transport rules

The FDF container itself is never treated as an incremental PDF history; each apply is one bounded append after the complete selected base revision

The operation never fetches the FDF file specification and never executes JavaScript or actions; see FDF Differences transport

Parsing, cancellation, policy, budget and publication failures preserve the loaded document and the existing output file

THPDFFDFPackage.DecodeDifferences · FDF Differences transport · THPDFHeadlessDocument