Dynamic HTML Lab: About
The term Dynamic HTML has been bounced around, with different
meanings, since the Web's inception. Originally, it was used to describe
the customized pages generated by Server Side Includes.
This HTML-on-demand was built with information received about the user's browser and operating system or in response to a client request.Search results, form posting verification and displayed database records are all examples of what we once knew as Dynamic HTML. HTML, that is, produced in response to custom input but before downloading and display by the user's browser.
Today Dynamic HTML refers to technologies that allow documents to be changed after their initial display, without server access, through user interaction and client-side scripting. Page elements can be displayed selectively, then modified, moved or replaced. This ability to move and replace objects allows for the animation of text and graphics. In turn, selective display and replacement can be used for database record retrieval. Personal home pages as well as complex business applications can make use of the technology. Pages look and feel like native operating system applications, and all without straining bandwidth and server links.
And now the bad news... Both Netscape and Microsoft have proposed their own version of Dynamic HTML. Even though we believe the two will converge soon, at present they are quite different.Netscape has packaged the following under the term Dynamic HTML:
using Cascading Style Sheets (CSS) and
using Cascading Style Sheets (CSS) and the <LAYER> tag
using Bistream's True Doc technology.
Microsoft's Dynamic HTML is more ambitious. It supports CSS Styles and Positioning but expands on HTML itself with a host of new tags. Combined with additions to the scripting languages, an author is promised complete access to all page elements. All attributes are exposed to client-side scripts.
A SITE THAT degrades gracefully for all
browser versions. This site can be viewed and appreciated by visitors
using Navigator 2, 3 and 4 and MSIE 3 + 4.
A SITE ON DHTML that uses
We Are Not...
APOLOGISTS for Netscape or Microsoft. Both have pushed the development of HTML in new directions, and both, in their own ways, have frustrated and confused authors.
A CODE CUT-AND-PASTE column
A REHASH OF THE MANUALS or technical
Netscape has released a final product that supports their version of DHTML. Their CSS implementation, however, remains incomplete. The problem list in the Preview Releases has now become the "Known Issues" page for Communicator 4.01 (a.k.a. Preview Release 7). See Links.
Microsoft has delivered a second beta, much more stable and certainly ambitious. Like Netscape, the finalized features are the proprietary ones, while the standards (eg. CSS) are still incomplete.
The W3C recommendation that may bring the two giants to agree on a single direction is the Document Object Model spec. Let's hope it is finalized soon.
A Word About PNGs
This column will try to include new technologies as they are finalized. PNG images are slowly becoming available. This column will include PNGs, for those able to view them, in the coming weeks. Information on displaying PNGs is linked to from our Links page.
In the Weeks to ComeAmong other topics, we plan on covering:
WHY NOT TAKE ALL OF
Canvas Mode and Browser Interface Customization
I SHOT THE SERIF:
The Return of Style with CSS and Dynamic Fonts
Layout to-the-pixel with CSS.
HOW I LEARNED TO STOP WORRYING AND LOVE THE <OBJECT> TAGand everyone's perennial favourites:
MY CLASSID'S BIGGER THAN YOURS
TAKE ACTIVE-X, PLEASE
Produced by Peter Belesis andAll Rights Reserved. Legal Notices.