- From: Joseph Scheuhammer <clown@alum.mit.edu>
- Date: Mon, 6 Jul 2015 10:36:49 -0400
- To: Michiel Bijl <michiel@agosto.nl>, Richard Schwerdtfeger <schwer@us.ibm.com>
- Cc: WAI Protocols & Formats <public-pfwg@w3.org>
> Is there any reason to not use aria-describedby for this?
> aria-errormessage essentially does the same thing, but with a more
> meaningful attribute.
First, an aria-errormessage is a more specific semantic, declaring that
the text is an error message. Otherwise, it is a description, but it's
unknown what kind of description.
Secondly, adding aria-errormessage would allow a control to have both a
description (e.g., tooltip) and an error message as separate pieces of
information. The error message is transient, and exists only when the
user enters an invalid value. In contrast, the description is permanent
providing a brief explanation of the function of the control.
For example, consider a high school physics simulation of heating
various liquids. One of the controls is an input for setting the
temperature of a Bunsen burner. The description for the input is "Sets
the maximum temperature of the liquid, with values between 0 (off) and
200 degrees Celsius". If the user entered, say "-25", an error message
pops up: "Temperature out of range. Please enter a value between 0 and
200".
In terms of ARIA markup:
- aria-describedby points to the description.
- aria-invalid flips between "true" and "false", depending whether the
value is within the range.
- aria-errormessage is added to the element when aria-invalid is true,
and points to the error message.
- aria-errormessage is removed when aria-invalid is false.
--
;;;;joseph.
'Array(16).join("wat" - 1) + " Batman!"'
- G. Bernhardt -
Received on Monday, 6 July 2015 14:37:23 UTC