Technique ARIA9:Using aria-labelledby to concatenate a label from several text nodes

Example 1: A time-out input field with concatenated label

A text input allows users to extend the default time before a time-out occurs.

The string "Extend time-out to" is contained in a native label element and is associated with the input with the input by id="timeout-duration" . This label is associated with this input using the for/id association only on user agents that don't support ARIA. On user agents that support ARIA, the for/id association is ignored and the label for the input is provided only by aria-labelledby, per the accessible name and description calculation in the HTML to Platform Accessibility APIs Implementation Guide.

The aria-labelledby attribute on the text input references three elements: (1) the span containing the native label, (2) the text input containing the default text '20' (recall that this input is not labelled with the for/id associated label text), and (3) the string 'minutes' contained in a span. These elements should be concatenated to provide the full label for the text input

<form>
<p><span id="timeout-label" tabindex="-1"><label for="timeout-duration">Extend time-out to</label></span>
<input type="text" size="3" id="timeout-duration" value="20" 
    aria-labelledby="timeout-label timeout-duration timeout-unit">
<span id="timeout-unit" tabindex="-1"> minutes</span></p>
</form>

Working example, Time-out input field with concatenated label, adapted from Easy ARIA tip #2: aria-labelledby and aria-describedby, an example put together by Marco Zehe.

Example 2: A simple data table with text inputs

A simple data table containing text inputs. The input labels are concatenated through aria-labelledby referencing the respective column and row headers.

<table>
	<tr>
		<td></td>
		<th id="tpayer">Taxpayer</th>
		<th id="sp">Spouse</th>
	</tr>

	<tr>
		<th id="gross">W2 Gross</th>
		<td><input type="text" size="20" aria-labelledby="tpayer gross" /></td>
		<td><input type="text" size="20" aria-labelledby="sp gross" /></td>
	</tr>
	
	<tr>
		<th id="div">Dividends</th>
		<td><input type="text" size="20" aria-labelledby="tpayer div" /></td>
		<td><input type="text" size="20" aria-labelledby="sp div" /></td>
	</tr>
</table>

Working example, Using aria-labelledby for simple table with text inputs, based on an example by Jim Thatcher.

Example 3: A conference workshop booking table

A conference workshop booking table with two parallel tracks allows users to select the workshop they want to attend. When tabbing through the checkbox inputs in the table, the track (1 or 2), the title, and the speaker of the workshop followed by the adjacent checkbox label "Attend" are provided as concatenated label for the checkboxes via aria-labelledby.

Some browser / screen reader combinations (e.g. Mozilla Firefox and NVDA) will in addition speak the relevant table cell headers.

<h1>Dinosaur Conference workshops timetable Thursday, 14.  & Friday, 15. March 2013</h1>
<table>
<caption>Dinosaur Conference workshop booking table</caption>
<tbody><tr>
	<td rowspan="2"></td>
	<th colspan="2" scope="colgroup">Thursday</th>
	<th colspan="2" scope="colgroup">Friday</th>
</tr>

<tr>
	<th scope="col" id="am1">9 to 12 AM</th>
	<th scope="col" id="pm1">2 to 5 PM</th>
	<th scope="col" id="am2">9 to 12 AM</th>
	<th scope="col" id="pm2">2 to 5 PM</th>
</tr>

<tr>
	<th id="track1" scope="row">track 1</th>
	<td>
		<h2 id="title-TM1">The Paleozoic era </h2>
		<p>2 places left</p>
		<p><input type="checkbox" id="TM1" aria-labelledby="title-TM1 track1 am1 TM1-att">
                <label id="TM1-att" for="TM1">Attend</label></p>
	</td>
	
	<td>
		<h2 id="title-TA1">The Mesozoic era overview</h2>
		<p>2 places left</p>
		<p><input type="checkbox" id="TA1" aria-labelledby="title-TA1 track1 am2 TA1-att">
                <label id="TA1-att" for="TA1">Attend</label></p>
	</td>
	
	<td>
		<h2 id="title-FM1">The Triassic period, rise of the dinosaurs</h2>
		<p>1 place left</p>
		<p><input type="checkbox" id="FM1" aria-labelledby="title-FM1 track1 pm1 FM1-att">
                <label id="FM1-att" for="FM1">Attend</label></p>

	</td>
	
	<td>
		<h2 id="title-FA1">The Jurassic period</h2>
		<p>11 places left</p>
		<p><input type="checkbox" id="FA1" aria-labelledby="title-FA1 track1 pm2 FA1-att">
                <label id="FA1-att" for="FA1">Attend</label></p>
	</td>
</tr>


<tr>
	<th id="track2" scope="row">track 2</th>
	<td>
		<h2 id="title-TM2">The Cretaceous period</h2>
		<p>18 places left</p>
		<p><input type="checkbox" id="TM2" aria-labelledby="title-TM2 track2 am1 TM2-att">
                <label id="TM2-att" for="TM2">Attend</label></p>
	</td>
	
	<td>
		<h2 id="title-TA2">The end of the dinosaurs</h2>
		<p>2 places left</p>
		<p><input type="checkbox" id="TA2" aria-labelledby="title-TA2 track2 am2 TA2-att">
                <label id="TA2-att" for="TA2">Attend</label></p>
	</td>
	
	<td>
		<h2 id="title-FM2">First discoveries of dinosaurs</h2>
		<p>2 places left</p>
		<p><input type="checkbox" id="FM2" aria-labelledby="title-FM2 track2 pm1 FM2-att">
                <label id="FM2-att" for="FM2">Attend</label></p>
	</td>
	
	<td>
		<h2 id="title-FA2">Emerging scholarship</h2>
		<p>19 places left</p>
		<p><input type="checkbox" id="FA2" aria-labelledby="title-FA2 track2 pm2 FA2-att">
                <label id="FA2-att" for="FA2">Attend</label></p>
	</td>
</tr>
</tbody>
</table>

Working example: Conference workshop booking timetable.