Re: WWW UI events

Daniel Dardailler (
Thu, 19 Jan 1995 21:52:59 +0100

> >I guess you're referring to supporting the new HTML 3.0 FIG construct
> >at the protocol level - I saw your message on www-html.
> I think the development of certain message protocol is inevitable as
> input tech. advances. Now we have mouse, pen (SCRIBBLE stuff), someday
> we'll have some VR gear... The question is whether we should have a
> logical framework to facilitate the development rather than let it happen
> in an ad hoc and eventually chaotic way.

The question at stake is also whether this "logical framework" should
be built on top of HTTP, on top of something else, or shouldn't be
built at all - i.e. something already exists.

> Well, there is a philosophical difference between www UI event (proper as
> what I perceived) and X or other GUI events, if I understand it
> correctly:

(-- delete analysis of diff betwen X events and WWW events)

What I think you described is really the differences in terms of
events handling and expectation between a low level UI protocol
(e.g. X) and a high level UI protocol (a UIMS).

A UIMS typically provides this level of service: rubberbanding,
selection of a item in a menu, choice of a value in a scale. The
implementation of the dialog (whether or not the valuator is a Scale
widget or a SpinBox widget) and therefore the visual feedback, as you
said, is typically done on the "display side" while the logic of the
application is done where the app is run, on the "other" side.

This model happens to match the Web browser/httpd architecture, but
this is a coincidence more than anything else :-)

> I submit that certain UI message protocol for www is useful and necessary
> and that we should pay attention to design a proper message
> hierarchy.

I got your point about X events being of one kind and WWW events of
another, but I'm still concern that we try to re-invent the UIMS wheel

To some, HTML Forms over HTTP POST (or ISMAP for that matters) might
be considered as a rudimentary UIMS, but we have to remember that
these WWW protocols were not designed to make it easy or reliable for
the server to maintain any state about a specific conversation, or to
exert any real control over the conversation.

For instance, a WWW viewer expects a reply from the server following a
form submission but as far as I know, it has no guarantee of a reply,
and it won't be informed if there is no reply (or that forms are
presented multiple times or out of order, etc). There is very little
dialog control available to the information provider.

I'm not flaming the Web here, all this just stems from the original
design goals of HTTP, its statelessness in particular, and we have to
be careful when shifting our goals.

> [an easter egg in netscape 1.0]
> >Is it present in the 0.9 version of Netscape, or just in 1.0 ? (I
> >don't want to spend my morning clicking on the logo for nauth' :)
> I believe it's in 1.0 only. I've checked that their photo.cgi script
> was dated Jan 5 1995.

I got it!

One day, I'll have to mention all the eggs I put in libXm over the
years... No I'm kidding, we just stuffed the demos, never the widget
set (besides bugs :-)

Daniel Dardailler | Email :
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