IE 8: alt change and longdesc weirdness

Update for IE 8b2

I have updated the results for IE8 b2, and included tests for input type=”image”

• Tests and results for HTML 4.01 transitional.
• Tests and results for HTML 4.01 strict.

update end.

Reading through the What’s New in Internet Explorer 8, this caught my attention:

The alt attribute is no longer displayed as the image tooltip when the browser is running in IE8 mode. Instead, the target of the longDesc attribute is used as the tooltip if present; otherwise, the title is displayed. The alt attribute is still used as the Active Accessibility name, and the title attribute is used as the fallback name only if alt is not present.

So IE 8 falls into line with the HTML 4.01 specification and other major browsers in regards to not using alt attribute content as a tooltip – good news.

Then it starts to get strange “instead the target of the longdesc attribute is used as the tooltip if present“. So now we have support for longdesc in IE8?? But how is that going to work… Does the tooltip show the text content of the target file? Does it show structure and formatting?

Just when it was thought that the longdesc had been assigned to HTML heaven, Microsft have decided to support it…

Testing support

To test out the changed alt and added longdesc support a test page with some combinations of alt, longdesc and title was created.
The results were mixed:

• The alt is not displayed as a tooltip when using HTML 4.01 strict DOCTYPE or XHTML DOCTYPE’s.
• The alt is displayed as a tooltip when using a HTML 4.01 transitional DOCTYPE.
• The longdesc attribute target URI content is not displayed as a tooltip as stated in the documentation.
• The URI contained in the longdesc attribute is included in the MSAA Description property ((accDescription) information about the control that doesn’t fit into any other field). In previous IE versions it was not.

So the implemenation of the longdesc is not complete (or perhaps the testing is at fault), but clearly something is going on with the longdesc in IE8 as evidenced when you look under the hood at the MSAA information.

Note:

Having re-read the documentation and discussed it with my colleague Gez Lemon who pointed out to me my mis-interpretation of the mircrosoft documentation: The URI will be displayed as a string in the tooltip, not the content of the URI as I interpretated it as initially. this would explain the URI being in the MSAA Description property.