Re: Scripting in Gnome

[James Henstridge <james daa com au>]

On 5/02/2004 11:06 AM, jamie wrote:

> Sounds very promising. The examples were interesting because thats the
>
> kind of stuff im interested in too. I was thinking more on the way VBA
> does things - It has application specific objects which provide a nice
> clean object interface to scriptable stuff in an application so i would
> want to replicate that and also allow a macro to interact with other
> apps in the same way ( the object interface would of course hideaway the
> bonobo calls and other glue that AT-SPI uses). Its good stuff - strange
> that it was hidden away, you should definitely talk it up a bit more...
>  
What you mention here is not a feature of VBA.  Instead, the feature is 
that pretty much every non-trivial Windows app exposes APIs via the same 
scripting interface (COM).  VBA (and Jscript and Python and Perl and 
...) have a binding for this scripting interface, which essentially 
gives them the ability to script these applications for free.  This is 
possible because COM provides an introspection interface, so the VBA 
interpreter can find out what methods exist on an object, and how to 
invoke them.

If the majority of apps on the Gnome desktop exposed their object model 
via CORBA, then a CORBA binding for a scripting language would give 
similar benefits to VBA's COM glue code (and if most apps exposed the 
document model via dbus or dcop, then a dbus or dcop binding would 
provide those benefits).

Following on from this, you can probably see that choosing a language is 
a very small part of making "Scripting in Gnome" work.  The hard part is 
getting all the applications to support it.

For the Linux desktop, this is particularly hard because it isn't clear 
which scripting interface should be used.

   * For Gnome, the answer would probably have been CORBA a few years
     back (this is less clear cut these days).
   * For KDE, the obvious answer is DCOP.
   * For Mozilla, components are exposed in process to Javascript via
     XPConnect.  They don't have an out of process interface.
   * I think OpenOffice also has something similar to Bonobo or XPConnect

The language support for each of these different solutions is different, 
so a developer's choice of interface will affect who can actually use 
it. Maybe in the future dbus will fill the role of "the scripting 
interface for the linux desktop", but it isn't quite ready for prime 
time yet (as far as I know).

James.

--
Email: james daa com au
WWW:   http://www.daa.com.au/~james/