Nov. 14, 1997 Issue > Web Authors

"Dynamic HTML" authors welcome dom, sort of

DHTML 2nd Edition

By D.C. Denison
Rank: 3

hatever else Dynamic HTML is, it's a hot publishing topic. More than two dozen DHTML books are scheduled to be published before the end of the year. Which means that there are at least two dozen authors out there who've been trying to figure out how to make this amorphous-but-sexy concept work in two annoyingly different implementations: Microsoft's and Netscape's.

We contacted a few of these early DHTML authorities, and asked them how they think the W3C's new DOM spec will affect the ever-evolving concept of Dynamic HTML.

A Moving Target

When Simon St. Laurent began working on his book, Dynamic HTML: A Primer, he saw a promising investment opportunity.

"I wanted to buy stock in an aspirin company," he recalls. "It was just so painful. I mean it's possible to write stuff that works in both the Netscape and Microsoft browsers, but you end up with so much code it just wasn't worth it. Eventually, I just re-wrote my examples for each browser."

"It was really frustrating," he continues, "because the idea of Dynamic HTML is so appealing. In a way, it's too good not to happen: the idea that you can use it to build a real interface. You can use DHTML to set up a menuing system, or an expandable outline. Have you see the asteroid example on the Microsoft page? It's crude, but if you can do that, you can do anything."

When W3C released the Document Object Model in early October, St. Laurent was hopeful.

"It obviously leaned a lot more towards the Microsoft model, and that's fine," he says. "I'm generally partial to Netscape, but I had to admit that Microsoft beat them on this one: Netscape's "layers" just doesn't work as well. And the DOM improves on the Microsoft model -- it works better with XML, for example."

Is there a way for Netscape to gracefully adopt the DOM spec?

"I think so," St. Laurent replies. "What you can do with Netscape's layers you can sort of do with the Microsoft/W3C "div" element. Sort of. That's one way that Netscape can go."

Yet although St. Laurent is enthusiastic about the DOM, and its promise to ease DHTML authoring, he's not holding his breath.

"Dynamic HTML is really a moving target," he says. "My book came out in August, and I've had to maintain an update page just to keep up with the changes. The W3C's DOM is a welcome development, but I think it's going to be a long time coming. They are tackling a lot of structural issues with this spec, and that will stretch out the development time."

St. Laurent is clearly hoping that the new specification catches on before his publisher schedules the next print run for his book.

"That's one thing I've thought about," he says, "and I've thought about it often: a successful Document Object Model would make the next edition of my book a whole lot easier to write."

Interesting Little Quirks

"If you include CSS2 with DOM, I think these specification are absolutely critical to the general acceptance of DHTML," Shelley Powers, author of the forthcoming Dynamic HTML Power Guide (IDG) says. "I have found, and I bet others have also, that the early acceptance of DHTML has been lukewarm at best. This was surprising to me at first because I couldn't believe that people wouldn't jump at the chance to have such a fine level of control of a page's presentation, or be able to dynamically move, layer, and alter HTML content.

"However, what people are seeing is that the W3C is releasing specification after specification, all of which impact on Web page authoring and development. And the two most popular browsers, Navigator and Internet Explorer, implement the dynamic capabilities of DHTML differently. Web page authors and developers know that both IE 4.0 and Navigator have 'interesting little quirks' with their DHTML implementations, to put it kindly. They know that DHTML content sizzles and pops with the 4.0 browsers, and looks awful with the older browsers. They know they are facing steep learning curves with scripting languages and scripting object models that are becoming progressively more complex, and difficult, to use. Think about it. When your language and model are simple, you can't do much, but what you can do, you can do quickly and easily. Now, one look at the Microsoft's Internet Client SDK, or the overwhelmingly complex examples that Netscape posts to 'explain' how to use the technology is probably enough to make the average Web page author go 'GACK!'

"Without DOM, or I should say without the concept of DOM hovering over the DHTML landscape, I think people are reluctant to take the time to deal with the cross-browser issues."

Despite her enthusiasm, Powers does not think that DOM will end DHTML browser incompatibility.

"Having implied that DOM should provide more general acceptance of DHTML, I need to add that my biggest concern, and my belief, is that DOM will not be the 'silver bullet' to the cross-browser compatibility problem," she says. "To do this, the DOM would have to include fairly rigid specifications for the types of objects in the object model, an exact specification for how they are related to each other, and each of the objects' properties, methods, and events. Then, there would have to be a blunt statement that no other extensions are acceptable in order for a browser to be compatible with the standard. I find this all very unlikely.

"DHTML is truly the Web's current Killer App Tool," Powers concludes, "but I am concerned that people are too burned out about new releases of technology to appreciate what they can do with it, even in its current less than perfect state."

What is Dynamic HTML?

• DHTML is the technology that enables control over content presentation and behavior, regardless of the user agent (such as a browser), or operating environment. This includes static properties that control the presentation, both visual and verbal, of an element, its position in relation to other elements, and its sensitivity to events, as well as more dynamic properties that can be used to alter the appearance, position, behavior, or display of an element after the contents are fully loaded.

Recent Quotes
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