View source for Using aria-alertdialog to Identify Errors

[[Category: Techniques]]
[[Category: ARIA Techniques]]
[[Category: Techniques in Development]]

== Status ==

* 4th Nov, Ready for TF review.
* 9th May, 2013. Rsponded to survey feedback https://www.w3.org/2002/09/wbs/35422/20130502tfaria/results#xalertdia 
* 9 May 2013 Ready to send to WG review once a live example is ready.
* Added to XML by AWK 2014/1/3

This technique should be listed in all situations (A, B, C) in 3.3.1 and 3.3.3 Understanding documents.

=== User Agent Notes [To be published separately] ===

* Jaws 13 and higher supports this technique.

== Applicability ==

This technique applies to HTML with WAI-ARIA.

This technique relates to Success Criterion (SC) 3.3.1. (Error identification):

* [http://www.w3.org/TR/UNDERSTANDING-WCAG20/minimize-error-identified.html  Understanding SC 3.3.1.]
* [http://www.w3.org/WAI/WCAG20/quickref/#qr-minimize-error-identified  How to meet SC 3.3.1.]

This technique relates to Success Criterion (SC) 3.3.3. (Error Suggestion):

* [http://www.w3.org/TR/UNDERSTANDING-WCAG20/minimize-error-suggestions.html  Understanding SC 3.3.3.]
* [http://www.w3.org/WAI/WCAG20/quickref/#qr-minimize-error-suggestions  How to meet SC 3.3.3.]

== Description ==

The purpose of this technique is to alert people that an input error has occured. Using role="alertdialog" creates a notification. This notification should be modal with the following characteristics:

* aria-label or aria-labelledby attribute gives the alertdialog an accessible name.
* aria-describedby provides a reference to the text of the alert.
* The alertdialog contains at least one focusable control, and the focus should move to that control when the alertdialog opens.
* The tab order is constrained within the alertdialog whilst it is open.
* When the dialog is dismissed, the focus moves back to the position it had before the dialog opened, if possible.

Note that the alertdialog should not be present in a way that it will be accessed by AT until it is needed. One way to do this is not to include it in the static HTML and instead to insert it into the DOM via script when the error condition is triggered. The insertion would correspond to the following HTML sample.

== Examples ==

=== Example 1 ===

This example shows how a notification using role="alertdialog" can be used to notify someone they have entered invalid information.

<pre>
<div role="alertdialog" aria-labelledby="alertHeading" aria-describedby="alertText">
<h1 id="alertHeading">Error</h1>
<div id="alertText">Employee's Birth Date is after their hire date. Please verify the birth date and hire date.</div>
<button>Save and Continue</button>
<button>Return to page and correct error</button>
</div>
</pre>

[http://pauljadam.com/demos/aria-role-alertdialog.html Live Example]

== Resources ==

* [http://www.w3.org/TR/wai-aria-practices/  WAI-ARIA Authoring Practices]

== Tests ==

=== Procedure ===

# Trigger the error that causes the alertdialog to appear.
# Determine that the alertdialog contains at least one focusable control, and the focus moves to that control when the alertdialog opens.
# Determine that the tab order is constrained within the alertdialog while it is open, and when the dialog is dismissed, the focus moves back to the position it had before the dialog opene, if possible.
# Examine the element with role="alertdialog" applied.
# Determine that either the aria-label or aria-labelledby attribute has been correctly used to give the alertdialog an accessible name.
# Determine that the contents of the alertdialog identifies the input error.
# Determine whether contents of the alertdialog suggests how to fix the error.

=== Expected results ===

Checks 2, 3, 5 and 6 are true. For SC 3.3.3, Check 7 is also true.