QGIS caches the data for the layers it is showing. This can be a bit annoying when the data changes and QGIS doesn’t know about this. What is missing is some kind of “reload layer data” function. Instead I have to remove layers and add them again all the time. Or, instead of reloading each layer, I reload the whole project. Still, this needs several clicks and after the reload you are back to the project extent instead of where you were before the reload.

A while ago I wrote a small QGIS plugin, to control a running JOSM or other OSM editor that supports the remote control API from QGIS. I finally got around to add it to the official repository so that you can now install it with a few clicks from inside QGIS.

Lately I have been working on OSM-derived data in QGIS and finding bugs in the OSM data in the process. To fix the data I have to go into an OSM editor (that’s JOSM for me), find the right position and do the actual fix. To make that process easier I added a button to the QGIS user interface that uses the JOSM remote control feature to tell the editor which area to load data for.

I spend a lot of time slicing and dicing OSM and other geodata. Sometimes that is done with custom software but often a database is involved somewhere. Recently that sometimes has been the SQLite/SpatiaLite duo which works great for simple things. But the heavy lifting has to be done with PostgreSQL/PostGIS which has much more “geo functionality” and is much faster when complex queries are used. So here comes the first tip: