Appendix A: Supported HTML tags

The HTML renderer accepts a bounded subset for rich text, structured blocks, tables, and explicitly mapped images

Structure and inline formatting

CSS cascade

Rules may appear in <style> elements or inline style attributes

Selectors support tag, class, ID, tag.class, and whitespace descendant combinations; unsupported attribute selectors, pseudo selectors, and sibling or child combinators are ignored

Matching declarations use CSS specificity and source order, inline declarations take priority, and !important is honored within the supported subset

Supported properties include the text, background, font, decoration, alignment, line-height, margin, padding, border, width, height, display and vertical-alignment properties listed below, plus the Flexbox, Grid and footnote properties in their respective sections

Lengths accept points, pixels at 0.75 points per pixel, em units, percentages, and unitless point values; font sizes also accept the standard keyword scale from xx-small through xx-large

Flexbox

display:flex and display:inline-flex support flex-direction, flex-wrap, flex, flex-grow, flex-shrink, flex-basis, justify-content, align-items, align-self, align-content, gap, row-gap and column-gap

Row containers distribute positive and negative free space per flex line, wrapped rows are measured independently, and column containers distribute an explicit or content-derived height

CSS Grid

display:grid and display:inline-grid support grid-template-columns, grid-template-rows, fixed, percentage and fr tracks, simple repeat() and minmax(), grid-column, grid-row, start and end properties, spans, gaps, row or column auto-placement, and per-item alignment

One container accepts at most 256 direct items and 64 rows or columns; nested content uses the same HTML renderer and layout cache

Footnotes

<footnote>, <aside style="float:footnote">, and <aside role="doc-footnote"> create numbered notes

Finite text boxes reserve the note area at the bottom before laying out later body lines; a reference and note that do not fit together continue to the next frame, and the continuation state preserves numbering

Tables

<table>, <tr>, <td>, and <th> render measured rows with backgrounds, padding, borders, text styles, and colspan up to 64 columns

Columns divide the explicit table width or available width equally, header cells default to bold text with a light background, and a row continues as one atomic unit in the next HTML text box

Nested tables, rowspan, border collapsing, and automatic content-driven column sizing are not part of this subset

Images

<img src="name"> draws an image previously bound with SetHTMLImage

The renderer supports width, height, margin, padding, border, background, and left, center, or right alignment; one missing dimension preserves the natural aspect ratio, and omitted dimensions use 0.75 points per source pixel

Image sources never trigger network or file access, measurement does not register resources, and repeated use reuses the bound image XObject

Bounds and recovery

One HTML input accepts at most 2048 stylesheet rules, 256 bytes per selector, 4096 bytes per declaration block, 4096 table rows, and 4096 table cells

Unknown properties, selectors, tags, and attributes are ignored while surrounding text is preserved; character references are decoded and malformed nesting is closed conservatively

Example

var
  LogoID: Integer;
begin
  LogoID := PDF.AddImageFromFile('logo.png');
  PDF.SetHTMLImage('brand-logo', LogoID);
  PDF.DrawHTMLTextBox(50, 750, 420, 180,
    '<style>.report h2 { color:#204080; } table { border:1pt solid #808080; }</style>' +
    '<section class="report"><h2>Quarterly report</h2>' +
    '<img src="brand-logo" width="72pt">' +
    '<table><tr><th>Region</th><th>Total</th></tr>' +
    '<tr><td>North</td><td>125</td></tr></table></section>');
end;