[oslc-core] Need to add alt/title property to the Compact UI Preview specifcation

[Bill Andreas]

The current specification of an OSLC Compact UI Preview defines an icon as 
part of the specification but does not provide a means to provide any 
accessibility information about that icon.  As a consequence, when the 
compact preview information is displayed, the visualization is not 
accessible (fails to provide an alternative explanation of an image).

The nub of the issue here is that the compact UI Preview defines an icon 
as simply a resource (a reference to an image file) but it does not allow 
information about that icon to be provided that is needed for to render 
"accessible" HTML markup.


Property 
Value-type 
Occurs 
Description 
oslc:icon 
Resource 
zero-or-one 
URI of an image which may be used in the display of a link to the 
resource. The image SHOULD be 16x16 pixels in size. 

When the UI renders the icon, we'll display something like:

<img class="iconNode" dojoattachpoint="iconNode" src="
https://rqmx64a.rtp.raleigh.ibm.com:9443/qm/web/com.ibm.asq.common.web/ui/internal/images/icons/obj16/qm_testcase16.gif
"> 

The accessibility issue is that there is no title or alt property 
associated with the image.  The icon conveys information (it's commonly a 
visual representation of the "type" of the thing being previewed).  Since 
the icon conveys information accessibility standards require that the alt 
or title (or both) properties be set on the img tag with a meaningful 
string assigned to them.

None of the values currently in the compact rendering specification are 
suitable for use as the alt/title text for the icon.  (So we leave 
alt/title unvalued and accessibility checking software immediately flags 
the rendered icon as failing accessibility).

There are a couple of ways this could be solved.  One mechanism used in 
some other standards is to simply allow the title/alt text (and 
potentially other HTML attributes) to be specified as arguments on the URI 
used to specify the image, e.g., "foobar.com/fancy_icon.gif?title=Fancy 
Pants Icon".  The other mechanism would be to add an attribute to the 
specification "Icon-alt-text" or some such thing.

In most uses, a single string is used as both the alt and title property 
of an img tag (the two properties serve a very similar purpose), so only 
one value is needed.  There are odd cases where someone might really want 
the alt text to be lengthier then the title text (the title text is 
displayed in a tooltip, the alt text is handed to screen readers and 
displayed if the icon doesn't load).

The need for specifying the alt/title text for the icon is rather 
pressing.   Longer term, there may be a need to allow other kinds of HTML 
properties to be specified (which is why some standards just throw these 
properties, as needed, onto the URI instead of making them separate 
attributes).  For example, there is talk that both the lang and dir 
attributes may need to be set on icons (some globalization people have 
been clamoring for this).  So in deciding how to best handle alt/title 
text, we may want to think about possible (similar) future needs,.

--  Bill Andreas

Senior Designer
Rational Software

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