QGIS Expressions Engine: Performance boost

Expressions in QGIS are more and more widely used for all kinds of purposes. For example the recently introduced geometry generators allow drawing awesome effects with modified feature geometries on the fly. The last days at the QGIS developer meeting 2017, I spent some time looking into and improving the performance for expressions. This was […]

QGIS2 compatibility plugin

Lately I’ve been spending time porting a bigger plugin from QGIS 2.8 to 3 while maintaining 2.8 compatibility. You can find it at https://github.com/opengisch/qgis2compat/ and http://plugins.qgis.org/plugins/qgis2compat/ One code to rule them all. My target was to have to edit the source code as little as possible to simulate a lazy or busy coder that has […]

Updating PyQt signals that use lambda in QGIS with 2to3

Just for the sake of documenting things, when running qgis 2to3 on a plugin I encountered a tricky situation regarding signals. MYQGISDIR/scripts/2to3 -f signals -w my/plugin/path The original code: extra_arg = “my test argument” QObject.connect( action, SIGNAL( “triggered()”), lambda extra_arg=my_arg: show_extra_arg(extra_arg)) def do_load_project(extra_arg): print extra_arg # “my test argument” The generated code: extra_arg = “test_arg” […]

QGIS: Qt5 and Python3 migration, current state

Behind the scenes a lot has happened to get ready for Qt5 and Python3. On the same codebase that is becoming the next release QGIS 2.16. This is really a great thing since we can focus work on a single master branch and I’m very happy that we got so far with this approach already. […]

Increasing the stability of processing algorithms

Processing just got a new testing framework to improve the long-term stability of this important plugin. And you can help to improve it, even if you are not a software developer! This is yet another piece in our never-stopping crusade to improve the stability and quality of the best desktop GIS on the market. Processing You probably […]

Passing android Intents to Qt

Working on QField I had the necessity of passing values from the QtActivity.java to the Qt cpp world, here how I did it using an Intent that is sent to the QtActivity (the one you should not edit that comes with Qt). For much more information see this post series. hopefully this will be helpful to […]

Syntactic sugar for PyQGIS

PyQGIS now supports a nice new addition for handling edit sessions in layers. This way, changes get committed automatically at the end of a successful (python) edit session.

with edit(layer):
    do your changes here()