Re: Advantage of XML based GUI? (was Re: Ada-inspired OS/Language)

[Ryan Tarpine <rtarpine@hotmail.com>]

Marin David Condic wrote:
> Trendy is nice, but there could be a technical advantage as well. Suppose you had an underlying Ada OS that had as
> one of its parts a graphics engine that interpreted XML-based markup to control the screen. The OS and any apps

Sounds similar to libglade for the GTK widget set on *nix/*BSD:
   http://freshmeat.net/projects/libglade/?topic_id=58

"Libglade is a small library that allows a program to load its user 
interface from an XML description at runtime"

> simply send properly formed markup to the engine to get things rendered and receive back XML markup for user
> supplied data. Assuming the scheme is well thought out & executed, you get some nice advantages. Change the engine
> and you can change the look&feel of all the apps - easier to create distinction between different OS releases. If
> you use an existing XML standard the apps become instantly portable. If the interface to the engine is properly

"The XML file format is that of the user interface builder GLADE..."

I don't know anything about GLADE, but that could be considered as an 
existing "standard".

> thought out, it should be no big deal to make an app work across a network. Another OS could run the apps simply by
> providing a compatible engine. From a low level an app can simply send/receive&parse XML, but a skin could be built
> on top of it to provide a more traditional calling interface for a windowing scheme. Build a different skin - get a
> different API with possibly different features.

"Libglade also provides a simple interface for connecting handlers to 
the various signals in the interface"

> 
> The advantage is that you can disconnect the apps/OS from the graphics display through an intermediary language,
> much like what web browsers do for the Internet with html.
> 
> MDC

I think XML is a good solution to the problem of UI.  There are many 
places XML is being used that is should not be (see 
http://ask.slashdot.org/article.pl?sid=02/07/15/212226&mode=thread&tid=99 
for it being used as a network protocol: incredible amounts of bandwidth 
-- often more precious than CPU cycles -- wasted), but I don't think 
this is one.

Ryan