Hi, i'm searching for a solution for updating field values easily while editing the layer.
I have a layer consisting of polygons which represent areas with a certain base value. Those values multiplied with the polygons area give a result value for the area which is interesting for us. We have to "remodel" the polygons (topological editing) to reach approximately some certain result values. It would be very nice to be able to have the polygon values be recalculated on each save action, so we can easily see the results without having to go to the attribute table, open field calculator, select all polygons, recalculate the result values from the $area and the base value manually. This is quite time consuming and really boring after a while. I thought that there might be a way through the actions tab, but unfortunately i have really no clue what to do there and basic informations are really rare or only towards presenting html stuff or sending values to other programs but not about editing fields in a layer (at least i didn't find any). I also know, that in spatialite, there is a possibility to have triggers to do such things, but those introductions are even more unexisting and mysterious. I would prefer (not personally) a way for shape files, cause the people i'm doing this for possibly think spatialite and such things are witchcraft or worse. So, has anyone an idea for an action (if possible at all), or an easy explanation for some trigger stuff? Thanx bernd -- Bernd Vogelgesang * Siedlerstrasse 2 * 91083 Baiersdorf * +49-9133-825374 _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
