Technique F42:Failure of Success Criteria 1.3.1, 2.1.1, 2.1.3, or 4.1.2 when emulating links
About this Technique
This technique relates to:
- 1.3.1: Info and Relationships (Failure)
- 2.1.1: Keyboard (Failure)
This failure applies to HTML.
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.
Note
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
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.
<span onclick="location.href='newpage.html'">Fake link</span>
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.
<img src="go.gif" alt="go to the new page" onclick="location.href='newpage.html'">
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.
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:
<p>
<img src="bargain.jpg"
tabindex="0"
alt="View Bargains"
onclick="doNav('viewbargains.html');"
onkeypress="doKeyPress('viewbargains.html');">
</p>
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.
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:
<div id="linklike">View the results of the survey.</div>
Related Resources
No endorsement implied.
Tests
Procedure
For all elements presented as links which use JavaScript event handlers to make the element emulate a link:
- Check if the programmatically determined role of the element is "link".
- Check if the emulated link can be activated using the keyboard.
Expected Results
- If check #1 is false then this failure condition applies and the content fails Success Criteria 1.3.1 and 4.1.2. If check #2 is false then this failure condition applies and the content fails Success Criteria 2.1.1 and 2.1.3.