server-side-image-map-absent
Server-side image maps must have a keyboard-operable alternative
Asks, for each <img ismap> inside a link, whether the page offers the same destinations as links a keyboard can reach, since a server-side image map has no keyboard-operable regions of its own.
Applies to. Applies to any scan scope. An <img ismap> inside an <a href> is a server-side image map: the browser sends the click coordinates to the link's URL, which has no keyboard-operable equivalent and exposes no individual regions to assistive technology.
Expectation. Each server-side image map is reported as cantTell: 2.1.1 is met when the same destinations are also offered as links a keyboard can reach, which the rule cannot verify. Client-side image maps (<map>/<area>) are not flagged. A scope with no <img ismap> passes. One whose only <img ismap> elements are outside a link is notApplicable: ismap does nothing there, so there is no server-side image map (the misplaced attribute is invalid HTML, a matter for the validator).
Examples
<img src="image.png" usemap="#nav" alt="Site map"><map name="nav"><area href="/x" shape="rect" coords="0,0,10,10" alt="Go"></map>
A client-side image map has no ismap attribute, which satisfies the rule outright. (An <img ismap> outside a link does nothing and makes the rule not applicable.)
<a href="/map-handler"><img src="image.png" ismap alt="Site map"></a>
ismap depends on the browser sending click coordinates to the server, so the map's regions cannot be reached from the keyboard; whether the page offers the same destinations as links is for a person to check. This rule never fails.
How to check
When this rule can’t decide, it reports cantTell and leaves the question to a person. Each question it can ask is listed here under its reason code, with the steps to answer it. A finding carries the same steps as howToCheck, in the scan’s language. See Output schema.
SERVER_SIDE_IMAGE_MAP
- Find the image map the report names and click its regions to list where each one leads.
- Put the pointer aside and press Tab through the page to the image link, then press Enter, and note what happens.
- Look elsewhere on the page for ordinary text links to each of the destinations you listed, and check you can reach and follow them with Tab and Enter.
Pass. Every destination of the image map is also offered as a link that works by keyboard.
Fail. Some destination can be reached only by clicking a point on the image, which fails WCAG 2.1.1.