Hi QGIS devs,
same question here but regarding rasters. I load a GDAL virtual raster that is being overwritten every time a new raster is available in a raster repository. Is there any way of reflecting the layer source updates (changes in the vrt file) in the map? In a more generic way, I'm attempting to visualize a tile-based raster, from which I cannot get all tiles at once. Do you think it could be possible in QGIS? P.S. Loading each tile as a separate layer wouldn't be possible because of performance. Thanks in advance, Germán Carrillo 2012/5/21 Germán Carrillo <[email protected]> > Hi Carson, > > have you tried updateFieldMap() from QgsVectorLayer? I've just had a > similar problem with memory layers and it turned out to do the trick. > > Regards, > > Germán > ----------------------------- > [1] > http://qgis.org/api/classQgsVectorLayer.html#ae7777703a20367b66ef0200e972f83d1 > > 2012/5/17 G. Allegri <[email protected]> > > You're right Carson. I used it only with a WFS layer, and in fact I see >> that WFS is the only providers that implements it. >> There would be the setDataProvider method on the vector layer but it's >> private... >> >> You've raised an important point, that I took for granted :( >> I fear that in this moment the only solution is remove it and reload it. >> giovanni >> >> >> >> 2012/5/17 Carson Farmer <[email protected]> >> >>> Hi Giovanni, >>> >>> Thanks for the tip. To answer your question: I am trying to >>> synchronise the layer with the datasource. Having said that, I don't >>> seem to be able to get 'reload' to work. It looks like reload is >>> reimplemented in QgsVectorLayer, which in turns calls the >>> dataProvider's reloadData method, so this may vary by provider type? I >>> tried it with a shapefile and a spatialite layer, and it did not seem >>> to do anything: I deleted several fields from the shapefile and added >>> a field to the spatialite layer in an external program, and these >>> changes were not reflected when I 'reloaded' the layers. Am I missing >>> something here? Perhaps there is something else needed to get the >>> changes to 'show up'? >>> >>> Cheers, >>> >>> Carson >>> >>> On Wed, May 16, 2012 at 4:36 PM, G. Allegri <[email protected]> wrote: >>> > Do you mean refresh the rendering or synchronizing the layer with the >>> data >>> > source? >>> > I usually use QgsMapLayer::reload() for the latter, and >>> > QgsMapCanvas::refresh() for the first. >>> > >>> > giovanni >>> > >>> > 2012/5/16 Carson Farmer <[email protected]> >>> >> >>> >> Hi list, does anyone know of a clever way to (programmatically) reload >>> >> a layer without actually removing it and re-adding it to the layer >>> >> list. Some context: I have a layer that sometimes gets updated by an >>> >> external application, and I want to be able to 'refresh' the layer >>> >> from the Python console to reflect these changes (new features, >>> >> deleted features, new attributes, etc.). I *could* simply load the >>> >> layer again, but I'm hoping there is a more efficient way to do this >>> >> (also I want to keep the current styling, layer order, unique layer >>> >> id, etc). >>> >> >>> >> Any thoughts/ideas? Note: assume we are working with a spatialite >>> layer >>> >> for now. >>> >> >>> >> Carson >>> >> >>> >> -- >>> >> Dr. Carson J. Q. Farmer >>> >> Centre for GeoInformatics (CGI) >>> >> School of Geography and Geosciences >>> >> Irvine Building, University of St Andrews >>> >> St Andrews, Fife, KY16 9AL >>> >> Scotland, UK >>> >> _______________________________________________ >>> >> Qgis-developer mailing list >>> >> [email protected] >>> >> http://lists.osgeo.org/mailman/listinfo/qgis-developer >>> > >>> > >>> >>> >>> >>> -- >>> Dr. Carson J. Q. Farmer >>> Centre for GeoInformatics (CGI) >>> School of Geography and Geosciences >>> Irvine Building, University of St Andrews >>> St Andrews, Fife, KY16 9AL >>> Scotland, UK >>> >> >> >> _______________________________________________ >> Qgis-developer mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-developer >> >> > > > -- > ----------- > |\__ > (:>__)( > |/ > > Soluciones Geoinformáticas Libres > http://geotux.tuxfamily.org/ > http://twitter.com/GeoTux2 > > -- ----------- |\__ (:>__)( |/ Soluciones Geoinformáticas Libres http://geotux.tuxfamily.org/ http://twitter.com/GeoTux2
_______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
