pdfOpenTagEx

BOOL32 __stdcall pdfOpenTagA(PPDF IPDF, TPDFBaseTag Tag, const char* Lang, const char* AltText, const char* Expansion);
BOOL32 __stdcall pdfOpenTagExA(PPDF IPDF, TPDFBaseTag Tag, const char* Lang, const char* AltText, const char* Expansion, const char* Attributes);

function pdfOpenTagA(const IPDF: PPDF; Tag: TPDFBaseTag; const Lang, AltText, Expansion: PAnsiChar): LongBool; stdcall;
function pdfOpenTagExA(const IPDF: PPDF; Tag: TPDFBaseTag; const Lang: PAnsiChar; const AltText, Expansion: PAnsiChar; const Attributes: PAnsiChar): LongBool; stdcall;

Purpose. Open a new structure element (push it onto a real open-tag stack) and emit the corresponding marked-content operator into the current page's content stream — the fundamental primitive behind tagged-PDF/PDF-UA accessibility structure trees. pdfOpenTagEx nominally adds custom attribute-dictionary support beyond the base form.

Description. Both are genuinely real and substantial (not a stub cluster at all, unlike what the "deferred, undocumented" history might suggest): OpenStructTagEx computes a real MCID (marked-content ID, counted per-page among already-registered structure elements), registers a full structure-element record (tag name, MCID, page index, parent linked via the current top of the open-tag stack — real parent/child structure-tree nesting, not a flat list), pushes the new element's index onto the stack, and emits the literal content-stream operator /<TagName> <</MCID n>> BDC. Tag (a TPDFBaseTag ordinal) is mapped to one of 52 real standard PDF/PDF-UA structure type names (Art, H1-H6, P, Span, Table, TD, Figure, Formula, etc. — the complete ISO 32000/PDF-UA vocabulary) via a fixed lookup table; any out-of-range ordinal silently falls back to 'Span' (a safe generic default, not a failure). MAJOR VERIFIED FINDING: pdfOpenTagEx's entire reason for existing — its Attributes parameter — is silently dropped. The wrapper's call to OpenStructTagEx is byte-for-byte identical to the plain pdfOpenTag's call, right down to hardcoding the underlying method's final Act (attributes) argument as the literal empty string '' — Attributes is never read at all. This is not merely "attributes are accepted but unused at serialization" — the internal storage array for this data, FStructAct, is real and presumably would be consumed at serialization if populated (its sibling field, FStructAlt, IS populated by AltText and genuinely serialized) — but there is no exported function anywhere in this entire SDK that ever supplies a non-empty value for it. pdfOpenTagEx is, in practice, a complete functional duplicate of pdfOpenTag — the "Ex" gives no additional capability.

Parameters.

Return value. True if a current content stream is available (i.e. a page is open) to emit the BDC operator into.

C# (P/Invoke)

[return: MarshalAs(UnmanagedType.Bool)]