What is Dynamic HTML?
Reviewing the W3C 'Document Object Model' section
http://www.w3.org/pub/WWW/MarkUp/DOM/,
it's clear what the W3C sees as 'Dynamic HTML'. The current draft requirements
detail an 'open' standard object model that allows total document and content
manipulation, that all elements (event those not directly supported by the
browser) within the document are programmable objects with support for mouse
and keyboard events, that all the document content can be manipulated (content
added, changed or removed 'on-the-fly', without a return trip to the server)
and that the document style sheet settings are also exposed as programmable
objects, allowing stylings to be changed on-the-fly. As such, it represents
a significant enhancement to static HTML and also to currently available
'dynamic' methods (i.e. scripting, server-side scripting/CGI etc.) 'Dynamic
HTML' is apparently supported by both Microsoft and
Netscape in Internet Explorer 4.0 and
Communicator 4.0. An 'open' standard supported by both
browsers...surely this is too good to be true...
Implementation
differences
Yes, it is!
Netscape's implementation of 'Dynamic HTML' revolves around
a slightly enhanced scripting object model, dynamic style sheets (through
proprietary Javascript style sheets), absolute positioning (primarily through
the use of layers - see
<LAYER>
and
<ILAYER>
and the
Layer
Object for all style sheet positioned elements).
Netscape does support full CSS positioning of elements,
but their position can only be manipulated by working through the
Layers
collection - and dynamic fonts (allowing fonts to be embedded in pages
and downloaded along with them). Microsoft's implementation
revolves around a significantly enhanced object model, dynamic style
sheets (through the W3C standard CSS object model), absolute positioning
(for all elements) and also implements some of the finer points of what 'Dynamic
HTML' should be by allowing direct document and content manipulation (the
ability to add, remove, or change any element or content). Essentially, Microsoft
have fully embraced the 'Document Object Model concept and HTML 4.0, previously
known as Cougar, for support in Internet Explorer
4.0.
To see what the W3C envisage as 'Dynamic HTML', visit
http://www.w3.org/pub/WWW/MarkUp/DOM/drafts/requirements.html,
as mentioned above, a document that details the requirements of the 'Document
Object Model' - the name the W3C is using, where Microsoft and Netscape use
'Dynamic HTML'.
Dynamic HTML specifics
The following pages detail the various standard 'Dynamic HTML' properties,
methods and events. Note that most of these are supported for almost every
possible HTML element by Internet Explorer, with
Communicator support being somewhat more limited. The details
are basically an overview (with examples) of the properties, methods and
events. For element/object specific properties, methods and events (and relevant
browser support details), see the specific element/object topics.
© 1995-1998, Stephen Le Hunte
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