Techniques for WCAG 2.0

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F42: Failure of Success Criteria 1.3.1, 2.1.1, 2.1.3, or 4.1.2 when emulating links

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.

Applicability

HTML and XHTML

This failure relates to:

Description

This failure occurs when JavaScript event handlers are attached to elements to emulate links. A link created in this manner cannot be tabbed to from the keyboard and does not gain keyboard focus like other controls and/or links. If scripting events are used to emulate links, user agents including assistive technology may not be able to identify the links in the content as links. They may be recognized as interactive controls but still not recognized as links. Such elements do not appear in the links list generated by user agents or assistive technology.

It is possible to use the ARIA role attribute to identify an anonymous element as link control for assistive technologies. However, best practice for ARIA calls for making use of native elements whenever possible, so the use of the role attribute to identify anonymous elements as links is not recommended.

The a and area elements are intended to mark up links.

Examples

Failure Example 1: Scripting a span element

Scripted event handling is added to a span element so that it functions as a link when clicked with a mouse. Assistive technology does not recognize this element as a link.

Example Code:


<span onclick="location.href='newpage.html'">
    Fake link
</span>

Failure Example 2: Scripting an img element

Scripted event handling is added to an img element so that it functions as a link when clicked with a mouse. Assistive technology does not recognize this element as a link.

Example Code:


   <img src="go.gif" 
   alt="go to the new page" 
   onclick="location.href='newpage.html'">

Failure Example 3: Scripting an img element, with keyboard support

Scripted event handling is added to an img element so that it functions as a link. In this example, the link functionality can be invoked with the mouse or via the Enter key if the user agent includes the element in the tab chain. Nevertheless, the element will not be recognized as a link.

Example Code:


function doNav(url)
{
   window.location.href = url;
}

function doKeyPress(url)
{
   //if the enter key was pressed
   if (window.event.type == "keypress" &&
       window.event.keyCode == 13)
   {
      doNav(url);
   }
}

The markup for the image is:

Example Code:


<p>
	<img src="bargain.jpg"
		tabindex="0" 
		alt="View Bargains"
		onclick="doNav('viewbargains.html');"
		onkeypress="doKeyPress('viewbargains.html');">
</p>

Failure Example 4: Scripting a div element

This example uses script to make a div element behave like a link. Although the author has provided complete keyboard access and separated the event handlers from the markup to enable repurposing of the content, the div element will not be recognized as a link by assistive technology.

Example Code:


window.onload = init;

function init()
{
	var objAnchor = document.getElementById('linklike');

	objAnchor.onclick = function(event){return changeLocation(event,
'surveyresults.html');};
	objAnchor.onkeypress = function(event){return changeLocation(event,
'surveyresults.html');};
}

function changeLocation(objEvent, strLocation)
{
	var iKeyCode;

	if (objEvent && objEvent.type == 'keypress')
	{
		if (objEvent.keyCode)
			iKeyCode = objEvent.keyCode;
		else if (objEvent.which)
			iKeyCode = objEvent.which;

		if (iKeyCode != 13 && iKeyCode != 32)
			return true;
	}

	window.location.href = strLocation;
}

The markup for the div element is:

Example Code:


<div id="linklike">
View the results of the survey.
</div>

Resources

Resources are for information purposes only, no endorsement implied.

Tests

Procedure

For all elements presented as links which use JavaScript event handlers to make the element emulate a link:

  1. Check if the programmatically determined role of the element is link.

  2. Check if the emulated link can be activated using the keyboard.

Expected Results