[GRASS-dev] NVIZ state file format (was GRASS6.3 on Windows, nviz)

[Dylan Beaudette]

On Tuesday 28 August 2007 11:43, Michael Barton wrote:
> AFAICT, the current situation is that NVIZ will not properly read the state
> file that it writes. To 'fix' it to read it with the current file format
> and code approach will result in an incomplete 'fix' in that it still won't
> read parts of the state file properly.
>
> XML is a potentially good idea, but requires an external library AND I
> don't know XML well enough to implement this.

My 2 cents here. If we are using XML in other parts of GRASS (via external 
parsing libs) I think that it would be good to standardize on some flavor of 
XML for any misc. things like the NVIZ state file. XML is simple to read in a 
text editor, simple to parse with external tools, and simple to read/write 
with the appropriate libs. 

>
> I *think* I can fix it so that NVIZ in GRASS 6.3 can properly read and
> configure itself from a state file. BUT, I need to change the state file
> format a little bit to make it parseable. Basically, I need to add section
> delimiters (e.g., "start surf", "end surf").

This would be fairly simple in XML: 

<surface>
  <id>1</id>
  <name>elevation</name>
  <source>elev at mapset></source>
  <colormap>elev at mapset</colormap>

  ... other properties
</surface>

this type of construct could be used to define all of the pieces in the 
statefile, so that they can be *directly* read from the document tree:

get/set methods work on:
surface->id->property->value


> Should I go ahead and do this if I can?
>
> Alternatively, if someone else would like to take this on, I'd be more than
> happy.

thats the kicker... I do not know enough about XML in a C environment to do 
this / and a MS thesis is looming over my head right now... Sorry!

Thanks for the hard work Michael,

Dylan


> Michael
>
> On 8/27/07 12:31 PM, "Glynn Clements" <glynn at gclements.plus.com> wrote:
> > Michael Barton wrote:
> >> I don't know enough about xml (either creating or parsing in TclTk) to
> >> implement this, although it sounds like a viable idea otherwise.
> >
> > As NVIZ is a hybrid C+Tcl/Tk application, you can use an external
> > library (e.g. libxml) for parsing.
> >
> > Parsing XML in Tcl isn't viable, IMHO.
>
> __________________________________________
> Michael Barton, Professor of Anthropology
> Director of Graduate Studies
> School of Human Evolution & Social Change
> Center for Social Dynamics and Complexity
> Arizona State University
>
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
>
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-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341