Explanation of "Auto" Header Association in PBDesigner

This article explains how the "Auto" setting for data cells works in PBDesigner, including edge cases and visual examples.

🔹 What does "Auto" mean?

When you set Associated Header(s) Type = Auto for a data cell, the NAGIX Engine automatically links the cell to the correct <TH> header(s) based on:

• table structure
• row/column position
• row span / column span

WARNING: By default, the setting is None, which means the cell has no header association. This leads to accessibility errors. You should always use Auto or Custom tagging for accessibility compliance.

✅ Case 1: Simple Table with Headers

In a standard table where each data cell is under a visible <TH> header, setting "Auto" allows NAGIX Engine to automatically associate the <TD> with the appropriate <TH>.

<TD headers="TBL_1_TH_0_0_0">Cell 1</TD>

🔄 Case 2: Table with RowSpan / ColSpan

If a data cell visually spans two rows, you must manually update its Row Span = 2 in the Cell Accessibility settings. Otherwise, the NAGIX Engine cannot correctly interpret the structure, and the header linkage will fail.

🚫 Case 3: Table with Empty Headers

In this case, the headers are present as <TH> elements, but contain no visible content. If left as-is, the "Auto" detection will fail because such headers are considered empty.

To fix this, you must manually define static text in:

• Title Fixed Text
• Actual Fixed Text
• Alternate Fixed Text

Once these are set, "Auto" can correctly associate data cells with these headers.

📊 Case 4: Cross-tabulated Table with Hierarchical Headers

This case represents a cross-tabulated table where both row and column headers are present in a hierarchical form. Each data cell (<TD>) must be associated with multiple headers from both axes.

The "Auto" setting works correctly in this layout only if:

• The structure is well defined with visible <TH> tags
• Reading order and accessibility order are clearly aligned

This example shows how the NAGIX Engine uses the internal naming (e.g. TBL_1_TH_0_1) to link multiple headers to each <TD> cell. In complex data grids like this, "Auto" provides a scalable solution without requiring manual tagging per cell.

📌 Summary

Setting	Behavior
None (default)	No header is associated — leads to accessibility errors
Auto	NAGIX Engine auto-detects relevant headers based on table structure
Custom	Manual selection of header IDs from a dropdown list

To ensure accessible output, use Auto wherever the table structure supports it, and Custom when more control is needed.