The WHATWG Blog

Welcome to a new semi-regular column, "This Week in HTML 5," where I'll try to summarize the major activity in the ongoing standards process in the WHATWG and W3C HTML Working Group.

The biggest news is the birth of the Web Workers draft specification. Quoting the spec, "This specification defines an API that allows Web application authors to spawn background workers running scripts in parallel to their main page. This allows for thread-like operation with message-passing as the coordination mechanism." This is the standardization of the API that Google Gears pioneered last year. See also: initial Workers thread, announcement of new spec, response to Workers feedback.

Also notable this week: even more additions to the Requirements for providing text to act as an alternative for images. 4 new cases were added:

1. A link containing nothing but an image
2. A group of images that form a single larger image
3. An image not intended for the user (such as a "web bug" tracking image)
4. Text that has been rendered to a graphic for typographical effect

Additionally, the spec now tries to define what authors should do if they know they have an image but don't know what it is. Quoting again from the spec:

If the src attribute is set and the alt attribute is set to a string whose first character is a U+007B LEFT CURLY BRACKET character ({) and whose last character is a U+007D RIGHT CURLY BRACKET character (}), the image is a key part of the content, and there is no textual equivalent of the image available. The string consisting of all the characters between the first and the last character of the value of the alt attribute gives the kind of image (e.g. photo, diagram, user-uploaded image). If that value is the empty string (i.e. the attribute is just "{}"), then even the kind of image being shown is not known.

• If the image is available, the element represents the image specified by the src attribute.
• If the image is not available or if the user agent is not configured to display the image, then the user agent should display some sort of indicator that the image is not being rendered, and, if possible, provide to the user the information regarding the kind of image that is (as derived from the alt attribute).

See also: revision 1972, revision 1976, revision 1978, revision 1979, Images and alternate text.

Other interesting changes this week:

• revision 1951: define window.top
• revision 1956: "User agents must not run executable code embedded in the image resource."
• revision 1958: more notes on what is a valid image (a surprisingly difficult question)
• revision 1965: allow <a> elements to straddle paragraphs
• revision 1998: define what happens when you set onclick='' on a document outside a Window
• revision 1999: define javascript: in Window-less environments
• revision 2001: define 'directionality' in terms of the dir='' attribute for cases where the 'direction' property has no computed value
• revision 2002: define processing for the second argument to getDataURL() for image/jpeg
• revision 2004: specify how to handle transparent images in the toDataURL() method
• revision 2008: make patterns required in the <canvas> API
• revision 2016: when <script type=''> is given, it must match the type of the script, even if the script is Javascript
• revision 2019: remove autosubmit='' from the <menu> element

Tune in next week for another exciting episode of "This Week in HTML 5."

Lachlan Hunt and I recently gave a presentation entitled Getting Your Hands Dirty with HTML5 at the @media 2008 conference in London. The audience was mainly front-end developers; the kind of people who are using HTML to make a living, so it was a great chance to get the message out about some of the new features that have been under development.

The talk covered the Design Principles under which HTML5 is being developed, how some of the features of HTML5 can be used to enhance common web sites, and how people can get involved with the development of HTML5.

The presentation seemed to go reasonably well, especially given that we had not met till the morning of the talk although we did have fewer demos than I would have liked, both due to technical problems in the talk and a lack of time to prepare. So, for those who were at the talk (as well as those who were not), here are a somewhat random collection of demos of the HTML5 features we mentioned:

• A video demo I wrote (requires a therora-supporting video enabled browser such as these preview builds of Firefox or Opera — both those pages have more, and probably better, demos).
• Canvex; Philip Taylor's 3D game demo in Javascript + <canvas>
• John Resig's Cross Document Messaging Demo
• A simple document outline viewer to get a feel for how the new section elements work (note: doesn't seem to work in Safari for some reason)
• Safari team's demo of the client side database storage (requires a recent webkit-based browser)

If anyone who saw the presentation is reading this and would like to provide constructive criticism on the talk, I would really appreciate it; giving talks is fun so it would be nice to get better at it

The four hottest topics in the WHATWG Issues List are:

• Finding a suitable common codec for the video element.
• The accessibility of tabular data.
• Web Forms 2.
• Using markup from namespaces other than HTML in text/html.

The video codec issue is being actively worked on, but we're not close to a good solution yet (it's mostly an economic and political issue, not a technical one, which is why we don't have any transparency on this issue, sadly). I recently responded to most of the table-related feedback. Web Forms 2 work is waiting for a decision from the W3C's forms task force on whether WF2 will be integrated as-is into HTML5 or whether it will be changed before being merged. The namespace issue is the one I'm working on now.

The first thing I have to do is work out what the problem is! There has been a lot of discussion, but not much of it is focussed on a problem, most of it is focussed on possible solutions. One can't evaluate a solution without knowing what it's trying to solve, though. To this end, I have created a wiki page where I will note down any problem descriptions I can find as I read all 367 of the e-mails in this folder.

Feel free to help! If you want to coordinate, I'm Hixie in #whatwg on Freenode IRC.

The W3C is having its technical plenary day today, and a number of WHATWG contributors are there. It's hard to participate remotely in this event, but you can watch and listen — the W3C is publishing an audio stream (in Ogg; a Java applet alternative is available too), and has commissioned realtime captioning for the event. There's also W3C IRC channel on the topic on irc.w3.org, port 6665, channel #tp, password beantown * (a single asterisk) (it's not clear why there's a password, just go with it) (no password anymore). You can also chat with WHATWG contributors who are present at the event on our own IRC channel.

The agenda for the day is available from the W3C site. Don't forget to adjust the times from the Boston timezone to your timezone if you want to listen to a particular session.

The WHATWG has how published a snapshot version of the HTML5 spec for review. Ian Hickson wrote to the WHATWG mailing list:

Last November, as part of the feedback on the W3C HTML WG charter, I wrote an e-mail saying that I thought a realistic timetable would have a first working draft released in October 2007.

We don't really need archived copies with the way the WHATWG works, since everything happens in the open with a Subversion interface and everything, but, I figured that I should "publish" an archived copy anyway, so today I put out a frozen "call for comments" draft:

http://www.whatwg.org/specs/web-apps/2007-10-26/multipage/

If anyone was hoping for a semi-stable version to start reviewing the draft, I would say that this is it. We're pretty much feature-complete at this point, which is to say I don't think we'll be adding any major features to HTML5 going forward (though of course minor features like additions to certain APIs are likely to still occur).

There is a public issues list:

http://www.whatwg.org/issues/

...which has about 3700 issues in it. The next order of business is simply to go through all of those issues. I've been tracking the issue count since early October, and at the moment the count is reducing at a rate of about 7 a day, which works out to being about a year and a bit of solid work, which puts us on track to reach Last Call in 2009, as I predicted in the aforementioned e-mail.

I'd like to thank everyone here in the WHATWG community for helping make this work fun and pleasant. It's really nice to be able to work in such a friendly atmosphere. I hope the coming year will continue the same way!

Cheers,

I'd like to thank Ian for his hard work on editing the spec. Keep it up!