Some random thoughts

I’m currently attending the Mozilla 2008 summit in Whistler, British Columbia, Canada. Among all the good sessions we’re having, there are a couple that I definitely want to blog more about over the course of the next few days, but wanted to share a few thoughts right now so we all kind of know what to expect:

  • One of the big themes here at the summit is the effort at Mozilla to bring the Gecko platform to mobile devices. There are many ideas floating around, and it’s certainly going to also be an accessibility field. I have some ideas that I need to get formulated properly which I’d like to bounce off the community to get some feedback.
  • The Thunderbird and Calendar teams have done some great progress in their respective fields, and now that Thunderbird has moved to Gecko 1.9.1, and Calendar will follow after its 0.9 release, and then get integrated with Thunderbird 3, we’ll have some interesting times ahead getting the calendar controls accessible. ARIA is going to help a lot with that, and I’m looking forward to help formulate proper exposure of information to ATs for these.
  • Aaron’s and my talk about accessibility API and standards support in Firefox 3 stirred quite some interest, and I believe it helped quite a few people understand better how the different pieces connect to one another.
  • Speaking of ARIA, there have been a few people even asking outside sessions about it, and I’m hoping to be able to connect with Ray and John tonight at the bbq so we can finally talk a bit about jQuery and Amo and all the cool stuff surrounding it. So Ray, come and find me! 🙂

On a more organizational side, rumour has it that the rock slide that blocks the main highway from Whistler to Vancouver should either be cleared, or a good alternative route be found until we depart on Friday, so no change in travel plans is necessary. Let’s keep our fingers crossed for that! And let’s also hope that nobody got hurt in that rock slide.

Support for text attributes and spell checking is coming in Firefox 3.1!

For those of you on the bleeding edge, namely on the Firefox 3.1a1pre nightly builds, the Friday’s nightly build will include one big new feature in accessibility for 3.1: Text attributes and spell checking support!

This means that assistive technologies now have access to the attributes of any text run on a page via the IAccessibleHyperText::getAttributes or ATK/AT-SPI equivalent API calls.

For example, running today’s nightly build of Firefox 3.1a1pre on Windows, visiting my blog’s main page, bringing up Accessibility Probe, and navigating to the link below the Heading Level 1 that says “Marco’s Accessibility blog”, a call to IAccessibleHyperText::GetAttributes on the link accessible will get you this result:

getAttributes(1) = NULL

Not very fancy, huh?

Tomorrow’s build, however, will yield a completely different result:

getAttributes(1) = org.eclipse.actf.accservice.core.win32.ia2.IA2TextSegment[text=font-style:normal;language:en-US;text-align:center;font-size:40px;background-color:transparent;font-weight:bold;text-indent:0px;color:rgb(255, 255, 255);font-family:'Trebuchet MS','Lucida Grande',Verdana,Arial,Sans-Serif;text-underline-style:underlinesolid;,start=0,end=26]

So, not only do you get information about the font-family, style, color and backgroundcolor, you also get the language this text is in, the underline style, the font-weight etc.

Also when editing, and you misspell something, as soon as you hit spacebar and the red underline appears, the attributes of that word will change and will include “invalid:misspelling;”, indicating that this word is invalid in that it is misspelled. Of course, an according IA2/ATK event will be fired accordingly! Note that the denotation of this may change if the IAccessible2 and ATK groups decide on a different notation for misspellings. Right now, it follows the aria-invalid convention, and we hope that this will be accepted by the groups.

Over the next few weeks, we’ll fine-tune this feature to be a bit more performant and also iron out any last details that might come up.

But if you’re an assistive technology vendor and you’ve been waiting for us to finally expose these text attributes, now is the time to try them out and provide feedback.

Note that Thunderbird and other projects that will be moving to use the Gecko 1.9.1 platform will also get this feature. This means that inline spell checking notification can also be supported for those apps soon!

[Update]: This patch made it into Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1a1pre) Gecko/2008071803 Minefield/3.1a1pre just fine. So go take a peek!

Easy ARIA tip #3: aria-invalid and role “alert”

I know, I know, it’s been a while since I posted my last Easy ARIA tip. But I’m hoping that this one will find you all excited and willing to play with it some more!

The problem: You have a form, a contact form, for example, that you want to put some accessible error checking into. Common problems are e-mail addresses that are not valid, or a name that does not contain at least a first and a surname.

The form

Let’s start out with a simple form.

<title>Contact form</title>
<form method="post" action="post.php">
<fieldset><legend>Please enter your contact details</legend>
<label for="name">Your name (required):</label>
<input name="name" id="name" aria-required="true"/><br />
<label for="email">E-Mail address (required):</label>
<input name="email" id="email" aria-required="true"/><br />
<label for="website">Website (optional):</label>
<input name="website" id="website"/>
<label for="message">Please enter your message (required):</label><br />
<textarea name="message" id="message" rows="5" cols="80" aria-required="true"></textarea><br />
<input type="submit" name="submit" value="Send message"/>
<input type="reset" name="reset" value="Reset form"/>

Straight and simple, but we’re not here to win beauty prices anyway. 🙂

Checking for validity and notifying the user

Checking the validity and notifying the user consists of several steps:

  1. Checking if the e-mail address or entered name are valid. To keep it simple, we’ll check whether the e-mail address contains the “@” symbol, and if the name entry contains at least 1 space characters ” “.
  2. Setting the field’s aria-invalid attribute and giving it a value of “true”.
  3. Notifying the user via an alert that the value entered was incorrect. Instead of using an intrusive dialog box created by the JavaScript ‘alert’ function, we’ll use a simple WAI-ARIA widget to do it. This notifies the user, but lets them continue interacting with the form without any interruptions.

All of this happens when the input loses focus, meaning in the “onblur” handler.

The JavaScript code I wrote looks like this, inserted above the closing “head” tag:

<script type="application/javascript">

  function removeOldAlert()
    var oldAlert = document.getElementById("alert");
    if (oldAlert)

  function addAlert(aMsg)
    var newAlert = document.createElement("div");
    newAlert.setAttribute("role", "alert");
    newAlert.setAttribute("id", "alert");
    var msg = document.createTextNode(aMsg);

  function checkValidity(aID, aSearchTerm, aMsg)
    var elem = document.getElementById(aID);
    var invalid = (elem.value.indexOf(aSearchTerm) < 0);
    if (invalid) {
      elem.setAttribute("aria-invalid", "true");
    } else {
      elem.setAttribute("aria-invalid", "false");


The checkValidity function

The core is the checkValidity function. It takes three parameters: The ID of the input that is to be validated, the term to search for to ensure validity, and the error message to be inserted into the alert.

To see if it is valid, the function checks whether the indexOf the input’s value is anything greater than -1. A value of -1 or less is returned if the index of the search term could not be found within the value.

If invalid, the function does two things:

  1. It sets the element’s aria-invalid attribute to “true”, which will indicate to screen readers that there is invalid content in here.
  2. It will call the addAlert function to add the alert with the provided error message.

If the search term is found, the aria-invalid attribute is reset to “true”. In addition, any alert that still might be around is removed.

The addAlert function

This function first removes any old alerts. The function is simple: It looks for an element with id “alert”, and if found, removes that from the document object model.

Next, the function creates a div element to hold the alert text. It gets an ID of “alert”. And it gets a role set of “alert”. This is actually ARIA-inspired, even though it doesn’t say “aria” in the attribute name. The reason is that role is based on the XHTML role attribute module that was simply ported to HTML for simplicity.

The text is added to the div element, and the div element is added to the document.

The moment this happens, Firefox will fire an “alert” event to assistive technologies when this div appears. Most screen readers will pick this one up automatically and speak it. This is similar to the Notification Bar in Firefox that prompts you whether you want to save a password. Our one does not have any buttons to press, it just tells us what’s wrong.

Adding the magic to the “onblur” event

All that’s left now is add the event handler. We need to change the two inputs for e-mail and name for this:

<input name="name" id="name" aria-required="true" onblur="checkValidity('name', ' ', 'Invalid name entered!');"/><br />
<input name="email" id="email" aria-required="true" onblur="checkValidity('email', '@', 'Invalid e-mail address');"/><br />

Testing the example

I’ve put up the above as an static example page for you to try it out. If you use Firefox 3 and a current supported screen reader, try the following:

  1. Enter only your first name as the name. When tabbing, you’ll hear an alert that tells you you’ve entered an invalid name. You can then shift-tab back and correct the error.
  2. Enter an e-mail address that has no “@” symbol. When tabbing out of this field, you should hear a warning that says you didn’t enter a valid e-mail address.

In both cases, when returning focus to the field in question, your screen reader should tell you that this field is invalid. JAWS 9 supports this, but JAWS 8 does not, so this may not work in all versions of the screen readers supported.

A few questions that you might have

Why did you put both “(required)” in the label text and the aria-required attribute on some of the inputs?
Because if this were a real live form, and the site was being visited by a browser that does not yet support ARIA, we’d still want to give an indication that this is a required field.
Why don’t you set focus back to the invalid field automatically?
Because this is not allowed by at least the Windows API specs and possibly others. Also, letting the focus jump around without real user interaction too often is not a nice thing to do in general.

In conclusion

Personally, it is my hope that websites would include such techniques more often in the future when filling out forms. There’s nothing more frustrating than filling out a form with 20 or so fields, submitting it, only to find that field 3 was invalid, and having to go through all fields again to make sure the values were retained, or supplying some information redundantly.

This is one of those examples where, in my opinion, more direct accessibility and user-friendliness can be achieved by explicitly using some JavaScript in combination with ARIA.

I hope you found this little tutorial of some use! I’d welcome your feedback as always!

And of course, you’re welcome to enhance this little example as a “homework” to also check whether something valid was entered for the “message” textarea.

Previous Easy ARIA tips
  1. aria-required
  2. aria-labelledby and aria-describedby