Forms: Verwendung von aria-invalid zum Identifizieren und Ansagen fehlerhafter Felder

About the error messages

• JAWS and NVDA expose a field with aria-invalid=true as "invalid entry".
• VoiceOver with Safari on OSX or iOS reads out the field as "invalid data"
• The field's label (or other accessible name) is announced before the "invalid" notification.
• The field-specific error messages when associated with aria-describedby are read by JAWS and NVDA as one tabs to the fields. VoiceOver reads these automatically only in iOS ... the error message is announced after a slight pause after the label is read. In OSX on a MacBook Pro, the VO+Shift+h key combination causes the error text referenced by aria-describedby to be read by VoiceOver.

Features

• Places an aria-invalid attribute for a field only if the input data is not in the expected format. These also have generic error text alongside but the text is not tied to the field.
• Uses a standard generic error message against every field when no data is entered. The error message is tied to the form control using aria-describedby.
• The error displayed for a past date (after Jan 1, 2000) is associated with the field via markup
• Every form control that fails validation has a red border and an error icon to its right (placed via CSS) for visual reinforcement
• Date is not a required field; today's date is filled in as default
• The error message placed above the form is within a span tag with role=alert. The SPAN tagg is within an h2 and is read by NVDA and JAWS. VoiceOver reads it in iOS and OSX.