BeginTagA
Tagged PDF, Accessibility
Description
The trailing A denotes the ANSI (char) DLL entry point; the ActiveX/COM surface exposes only the Unicode form. Behaviour is identical to BeginTag and string arguments are interpreted using the current SetAnsiMode code page
Opens a tagged-PDF structure element on the current page. Writes a BDC (Begin Marked Content with Dictionary) operator to the content stream and registers the element in the document's logical structure tree. The structure tree is finalised automatically when the document is saved.
Tags must be balanced: every BeginTag call must be followed by a matching EndTag call. Tags can be nested.
Syntax
Delphi
Function DLBeginTagA(InstanceID: Integer; TagType, AltText, ActualText: PAnsiChar): Integer;DLL
int DLBeginTagA(int InstanceID, const char * TagType, const char * AltText, const char * ActualText);Parameters
| TagType | PDF standard structure type: P, H1–H6, Figure, Table, TR, TH, TD, L, LI, LBody, Span, Link, Note, etc. (see ISO 32000-1 §14.8.4). |
|---|---|
| AltText | Alternative text for images and other non-text content (maps to the PDF /Alt attribute). Pass an empty string if not required. |
| ActualText | Replacement text for content whose visual representation differs from its logical meaning (maps to the PDF /ActualText attribute). Pass an empty string if not required. |
Return values
| 0 | Failed (no document is open) |
|---|---|
| 1 | Tag opened successfully |
Example
// Heading, then a paragraph
PDF.SetPDFUAMode('en-US');
PDF.BeginTag('H1', '', '');
PDF.PrintText(50, 750, 'Introduction');
PDF.EndTag;
PDF.BeginTag('P', '', '');
PDF.PrintText(50, 730, 'This document demonstrates tagged PDF.');
PDF.EndTag;
// Figure with alt text
PDF.BeginTag('Figure', 'Company logo', '');
PDF.DrawImage(50, 650, 120, 60, 'logo.png');
PDF.EndTag;Remarks
Use BeginArtifact/EndArtifact for decorative content (page headers, footers, background elements) that should not be read by screen readers.
The document must be in write mode (created or opened for modification). Call SetPDFUAMode before tagging to satisfy PDF/UA-1 requirements.