The first significant changes to the table syntax are already available in version 6.2.1.

1. Introduction

Introduce a flexible markup for data tables. Any kind of tables allowed by HTML5 can be created using this markup, from the most basic examples (e.g. simple rows of cells) to complex tables with full support for accessibility options.

Backport and adaption of WikkaWiki Table Markup. Requires evaluation and changes, not all features are reasonable to implement.

2. Implementation Notes

2.1. HTML5 Table Cell Attributes

HTML5 table cells, defined by the <td> element, support several attributes for controlling layout, accessibility, and relationships with header cells. Many presentational attributes from earlier HTML versions are now deprecated in favor of CSS.

2.1.1. Core Supported Attributes

These attributes are valid in HTML5 and should be used for modern web development:

• colspan: Specifies how many columns a cell should span.
  • Example: <td colspan="2"> makes the cell span two columns.
• rowspan: Specifies how many rows a cell should span.
  • Example: <td rowspan="3"> makes the cell span three rows.
• headers: Associates a data cell with one or more header cells (<th>) by referencing their id values. This improves accessibility for screen readers.
  • Example: <td headers="header1 header2">.

2.1.2. Deprecated Attributes (Use CSS Instead)

The following attributes are obsolete in HTML5. Their functionality should be achieved using CSS:

• align → text-align or margin
• valign → vertical-align
• bgcolor → background-color
• width → width
• height → height
• nowrap → white-space: nowrap

2.1.3. Global Attributes

The <td> element also supports all global HTML attributes, such as class, id, style, data-*, and aria-* attributes for styling, scripting, and enhanced accessibility.

2.2. Considerations

1. use WackoWiki parameter pattern used by actions and formatters
   • (x=1 y=name)
2. ^ conflicts with ^^superscript^^ or ^C in cell content
   • The table cell separator is of utmost importance and should never conflict with other wiki markups.
   • I like the use of the caret ^ (CIRCUMFLEX ACCENT) here, maybe there is a simple workaround to mitigate the conflict with other syntax.
     • (?<!\^)\^(?!\^) ensures the ^ is not preceded or followed by another ^, matches only isolated ^ characters
3. use of full parameter names
   • e.g. id=tbl1_header or rowspan=2
4. support only indirect inline CSS (see Wrappers around formatters)
   • add parameter width= and support px as well as %
   • align= parameter issues and CSS shortcomings with dynamic tables
     • td:nth-child(2) { text-align: center; } is delightful for static tables
   • mainly a sanitization and validation issue

   •  <td class="[ ' class ' ][ ' bgcolor ' ][ ' align ' ]" style="width: [ ' width ' ];">	

5. current regex supports quotes like align="left" or class="style-1 style-2"
6. to keep it modest, omit some attributes
   • title
   • height
   • headers
   • for full HTML support use <# HTML here #>
7. add attributes also to table and caption
   • use table_attr() function to avoid spaghetti code
     • table: align, bgcolor, class, id, width
     • col: bgcolor, class, id, span, width
     • caption: align, bgcolor, class, id, side
     • cell: align, bgcolor, class, colspan, id, rowspan, scope, width, valign
   • table: #|(align=right)
     • float (same as wrapper- CSS classes), class, id
   • caption: ?|(side=bottom) Caption |?
     • id, side (caption-side: top | bottom)
   • col: !|(width=20%) |(width=20%) |(width=40% bgcolor=green) |(width=20% span=2) |!
     • id, class, span, width, align, valign, bgcolor
8. additional attributes are thinkable for font-size, nowrap and others all translating in adding an additional CSS class to syle="style1 sytyle2 ..."
9. add different table styles, default is usertable or dtable, replace table syle via #|(type=mytable)
10. add a popup for to WikiEdit to create a table with the provided column and rows, as well header and other options
11. catch logical errors and mitigate them
    • there can be only one caption and only at the top of the table
12. error sources
    • mistakenly using the wrong attribute name, row instead of col
    • writing the attribute name wrong, leaving out a letter or messing up letters when writing
    • data cells in the wrong column (e.g. broken legacy tables) due to missing cell spans

2.3. Rational

The parser breaks down the pipe syntax by row and then each cell. The row and cell syntax delimiter | determines each element and process it recursively.

row 1
→ cell 1 → content
→ cell 2 → content
row 2
→ cell 1 → content
→ cell 2 → content

To avoid syntax conflicts, the delimiter | is always on the inside.

#|
?| Fruit production in 2026 |?
*| | Apples | Pears |*
^| Mary | 300Kg | 320Kg ||
^| John | 400Kg | 630Kg ||
|#	

2.4. Syntax

2.4.1. Attributes

• thead / tfoot / tbody
• colgroup / col
• CSS: color, styles, width
  • via predefined classes
• Global Attributes: id, class, title, lang, data-*

2.4.2. Colors

1. background colors
   • table header
   • row highlighting
   • subtle background colors
   • web-safe color

2.4.3. Linebreaks

2.4.4. Spaces

|| cell ||
||(pattern) cell ||

2.4.4.1. Table Space Ignored

HTML and CSS whitespace handling explains why browsers ignore leading spaces in table cells. HTML preserves all whitespace in the source code as text nodes in the DOM, but CSS applies a default whitespace processing algorithm that collapses multiple spaces, tabs, and line breaks into a single space. This behavior is consistent across all inline content, including table cells.

When you have leading spaces in a <td> element, such as <td> Hello</td>, the browser processes the whitespace as follows:

• Leading and trailing whitespace (spaces, tabs, line breaks) before and after text is ignored in rendering.
• Consecutive whitespace characters (spaces, tabs, line feeds) are collapsed into a single space.
• Only the first space between words is preserved; extra spaces are discarded.

This is not a bug—it's by design. The goal is to ensure readable text formatting without requiring developers to worry about code indentation affecting the displayed layout. For example, the following HTML:

<td>   Hello World!</td>

is rendered as:

Hello World!	

with only a single space between "Hello" and "World!".

2.4.4.2. Solutions to preserve spacing

If you need to display multiple spaces (e.g., for monospaced text or formatting), use one of these methods:

• Use white-space: pre in CSS to preserve all whitespace:

  td {
    white-space: pre;
  }

• Use non-breaking spaces ( ) to force visible spacing:

  <td>&nbsp;&nbsp;Hello</td>

• Wrap text in a <pre> tag if you want to preserve all formatting exactly as written.

This behavior applies uniformly across modern browsers and is part of the standard HTML and CSS specification.

2.5. Issues

1. CSS specificity prevents bgcolor in <th> cells
   • .usertable th { background-color: #eee; }
   • highlight color for hovering above a table row
2. Currently, there is no way to apply a style to a table row using wiki syntax.
3. It is not possible to align the text of an entire column via the <col> element but possible via CSS selectors for the <table> element, you must use style=“text-align: center;” or td:nth-child(4) for a specific column; otherwise, the user must apply the style to each individual cell (and who wanna do this?).
   • table #|(class="defaultcenter col4right")
     • .col4right td:nth-child(4) {text-align: right;}
     • .defaultcenter {text-align: center;}
   • CSS selectors
     • default[left|center|right|top|middle|bottom]
     • colN[left|center|right|top|middle|bottom] N stands for the column number
4. As soon as you start defining multiple attributes cell by cell using wiki syntax in a large table with many columns and rows, it quickly becomes counterproductive, especially if you do this over and over again.
   • possible solutions:
     • inline HTML
     • content templates
     • keep it simple
5. Should it use the same attribute name align for the table alignment and the cell text alignment?
   • .table-[center|left|right]
   • .text-[center|left|right|justify]

2.6. JavaScript features

• sortable tables
  • https://github.com/tristen/tablesort
• table search
• column highlighting

2.7. Backwards Compatibility

The old colspan behaviour is not compatible with the new colspan or rowspan attributes, it would add a colspan where it not belongs.

It once expanded omitted cells at the end of a table row for the last cell to fit the previous rows columns.

By removing this behaviour, existing col spans will default to their original colspan which is 1. Just add the new colspan=Number attribute to the cell to restore the intended colspan.

<?php
// removed legacy colspan behaviour
if (   ($i == $count)
    && ($this->cols <> 0)
    && ($count < $this->cols))
{
    $colspan = ' colspan="' . ($this->cols - $count + 1) . '"';
}

2.8. Sanitization & Validation

• Discards attributes not on a whitelist for the given element.

2.9. Documentation

1. update Table section in Text Formatting page
2. add Table Markup Guide (draft)

2.10. Resources

• https://developer.mozilla.org/[...]nt/HTML_table_basics
• https://developer.mozilla.org/[...]rence/Elements/table
• https://html.spec.whatwg.org/m[...]ml#the-table-element
• https://alistapart.com/article/web-typography-tables/
• https://css-tricks.com/complete-guide-table-element/

3. Examples

#| 
|| ^ Heading 1 ^ Heading 2 ||
^| Heading 3    | Row 1 Col 2          | Row 1 Col 3 ||
^| Heading 4    | no colspan | ||
^| Heading 5    | Row 3 Col 2          | Row 3 Col 3 ||
|#	

#|
?| Fruit production in the last **two** years |?
*| |(colspan=2) Apples |(colspan=2) Pears |*
*| | 2025 | 2026 | 2025 | 2026 |*
^| Mary | 300Kg | 320Kg | 400kg | 280Kg ||
^| John | 400Kg | 630Kg | 210Kg | 300Kg ||
|#	

#|
||(align=left width=50%) left |(rowspan=3 valign=top) top |(rowspan=3 valign=middle) middle |(rowspan=3 valign=bottom) bottom ||
||(align=center) center ||
||(align=right) right ||
|#	

#|
||(rowspan=2) 2 lines | line 1 ||
|| line 2 ||
||(colspan=2) line 3, 2 columns broad ||
|#	

#|
^|(colspan=2 rowspan=2) 2x2 |(colspan=2) 2x1 |(rowspan=2) 1x2 ||
||(rowspan=2) 1x2 | 1x1 ||
|| 1x1 | 1x1 |(colspan=2) 2x1 ||
|#	

4. Feedback

Please provide feedback.