[gdal-dev] OGR style fields

[Tamas Szekeres]

Frank,

Mapserver is only a subset of the areas where this change would be
beneficial. There might be other renderers that would utilize the OGR
style support. I don't think this would eliminate the need of that
mapserver related RFC, though.

Would this change need an RFC on an explicit motion to vote on?

Best regards,

Tamas


2008/1/18, Frank Warmerdam <warmerdam at pobox.com>:
> Tamas Szekeres wrote:
> > Folks,
> >
> > Currently only a few of the OGR data sources have built in style
> > support, however we might want to preserve the style information when
> > copying the data from one data source to another.
> > As of the implementation of GDAL RFC 6 we could do such things easily
> > regardless of the target data source type, like for example:
> >
> > ogr2ogr -overwrite -f "ESRI Shapefile" -sql "select *,OGR_STYLE from
> > rivers where OGR_GEOMETRY='POLYGON'" rivers.shp rivers.tab
> >
> > would copy all of the polygons from a mapinfo layer and add a new
> > field containing the style string for each of the features.
> >
> > It would be quite trivial to prepare a data source independent support
> > to consume this information and return meaningful value when
> > OGRFeature::GetStyleString is called.
> >
> > As the benefit of this change we could consider each of these layer as
> > having internal style information. For example we could use the
> > mapserver STYLEITEM "AUTO" functionality with these layers.
> >
> > The most trivial implementation to achieve this would changing
> > OGRFeature::GetStyleString as follows:
> >
> > const char *OGRFeature::GetStyleString()
> > {
> >     int  iStyleField;
> >
> >     if (m_pszStyleString)
> >         return m_pszStyleString;
> >
> >     iStyleField = GetFieldIndex("OGR_STYLE");
> >     if (iStyleField >= 0)
> >         return GetFieldAsString(iStyleField);
> >
> >     return NULL;
> > }
> >
> > What do you think about this kind of addition?
>
> Tamas,
>
> I would not object to this though I'd note I plan to prepare a MapServer
> RFC to allow using OGR style strings from any datasource (not just through
> CONNECTIONTYPE OGR) in the next few weeks.  So from a mapserver point of
> view, I don't think this change is particularly necessary.
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | President OSGeo, http://osgeo.org
>
>