On Sat, Aug 14, 2010 at 11:18 AM, Even Rouault <[email protected]> wrote: > Hi gdal-devs, > > Here's a proposal for adding OGR_L_GetName() / OGRLayer::GetName(). > > The proposed patch in http://trac.osgeo.org/gdal/ticket/3719 introduces a new > virtual method GetName?() at the OGRLayer level. > > The semantics of this method is to return the same result as GetLayerDefn()- >>GetName(). This is indeed the default implementation of the OGRLayer class > itself. > > So, what is it usefull for ? A few drivers, like PG since > http://trac.osgeo.org/gdal/changeset/20277 , can benefit from GetName() by > overloading it, without needing to fetch the layer definition, which is an > operation that cost a few SQL requests per layer. > > So the new method can be usefull to present the list of layer names of a PG > database. > > This would also be very handy for a OGR WFS driver I'm writing. It would save > a DescribeFeatureType request for each layer. Just the GetCapabilities request > would be needed. > > Apart from the PG driver, there's only another driver (LIBKML) in trunk that > overrides GetName(), and its semantics matches the one explained above. So > there's no backward compatibility issue. > > IMHO, this change seems to be a bit light to deserve a whole RFC, but I wanted > to hear from your feedback before applying it.
Even, I'm generally ok with this change. I would like to see it made explicit that the name returned by OGRLayer::GetName() must always match the name returned by the OGRFeatureDefn::GetName(). I am also wondering if there are any other aspects that should be handled this way. Many applications want to show a list of laye names, and the geometry type of the layer (ie. ogrinfo, QGIS, etc). Should we also be making the geometry type a virtual method fetch on the layer? I can see the change you propose being of benefit to essentially all the RDBMS drivers. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [email protected] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
