Dynamic HTML Lab: About | WebReference

Dynamic HTML Lab: About


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Dynamic HTML




The Past

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.

More recently, scripting languages, such as JavaScript and VBScript, allowed changes to be made to a document after it left the server, but before it was displayed by the browser.

The Present

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:

STYLE SHEETS:
using Cascading Style Sheets (CSS) and
JavaScript Accessible Style Sheets (JASS)

POSITIONING:
using Cascading Style Sheets (CSS) and the <LAYER> tag

DYNAMIC FONTS:
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.


We Are...

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.
The same page is downloaded by all browser versions, but 4th generation releases will display the Dynamic HTML.

A SITE ON DHTML that uses DHTML
All our examples work now. If it is a promised feature, we'll wait to see if it is delivered, before including it.

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
We are firm believers in the old Greek proverb:
Give a man some cut-and-paste Dynamic HTML and he'll make a good web page today;
Teach him how to write dynamic HTML and he'll create good web pages for a lifetime.

A REHASH OF THE MANUALS or technical documentation.
We will select features and expand on them with working examples.
Complete official documentmention info can be found on our Links page.


The Future

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 Come

Among other topics, we plan on covering:

WHY NOT TAKE ALL OF ME:
Canvas Mode and Browser Interface Customization

I SHOT THE SERIF:
The Return of Style with CSS and Dynamic Fonts

POSITIONS, GENTLEMEN:
Layout to-the-pixel with CSS.

COFFEE-TALK:
JavaScript - Java Communication

HOW I LEARNED TO STOP WORRYING AND LOVE THE <OBJECT> TAG

and everyone's perennial favourites:

MY CLASSID'S BIGGER THAN YOURS
and
TAKE ACTIVE-X, PLEASE



Produced by Peter Belesis and

All Rights Reserved. Legal Notices.
Created: 07/23/97
Revised: 09/28/97

URL: http://www.webreference.com/dhtml/about.html