area elements of image maps HTML and XHTML Documents that contain area elements.
This technique relates to:
The HTML 4.01 specification explains that the text of the alt attribute
is to be displayed when the element cannot be rendered normally. User Agents will
display the alt attribute text when images are not displayed. However,
currently, visual User Agents do not display the alt attribute text for area elements
of image maps when accessed by keyboard or when images are not displayed, and may clip
the area elements if the intrinsic size of the image is not used. In addition, the
display of alt attribute text in response to mouse-hover does not display in the font
size or color combination set in the User Agent.
The title attribute is meant to provide additional information. However,
current implementation in User Agents is access to either the title or alt attribute,
but not both. User Agents generally will display the title attribute text
when the mouse is placed over the element containing the title attribute.
For example, Internet Explorer will display the alt text on mouse-over if
there is no title text, Firefox and Opera only display the
title text on mouse-over and do not use the alt attribute
text for this purpose. Thus, to ensure the alt attribute text is visible on
mouse-over, the same text should be used on the title attribute.
Therefore, when using image maps, successful implementation of this technique would require either:
Ensuring the area element alt attribute value is displayed in response to attaining focus (including keyboard focus), and that this applies both to situations where images are loaded and not loaded. OR
A redundant mechanism serving the same purpose as the area elements is present in the Web Page.
The objective of this technique is to provide text alternatives that serve the same
purpose as the selectable regions of an image map. An image map is an image divided into
selectable regions defined by area elements. Each area is a link to another
Web page or another part of the current Web page. The alt attribute of each
area element serves the same purpose as the selectable area of the
image.
This example uses the alt attribute of the area element
to provide text that describes the purpose of the image map areas.
Example Code:
<img src="welcome.gif" usemap="#map1"
alt="Areas in the library. Select an area for
more information on that area." />
<map id="map1" name="map1">
<area shape="rect" coords="0,0,30,30"
href="reference.html" alt="Reference" />
<area shape="rect" coords="34,34,100,100"
href="media.html" alt="Audio visual lab" />
</map> Resources are for information purposes only, no endorsement implied.
For each area element in an image map:
Check that the area element has an alt attribute.
Check that the text alternative specified by the alt attribute serves the same
purpose as the part of image map image referenced by the area element
of the imagemap.
The above checks are true.