OnXfaOpenFile event

Fires when an XFA script requests a file open or save-as operation (import/export of XML or XDP), providing the file flag, URL and mode

• FileFlag mirrors FXFA_SAVEAS_XML (1) or FXFA_SAVEAS_XDP (2) for save operations
• The host cannot return a real file handler through this event (FPDF_FILEHANDLER is ABI-internal), so the event is informational — the host performs its own file side-effect
• Unassigned leaves the request declined

TPdf.OnXfaEmail, TPdf.OnXfaHttpRequest