QGIS » QGIS Application

Further testing of aggregated’s @parent feature led to the discovery of another oddity, whereas a filtered aggregation with the following expression: (intersects($geometry,geometry(@parent))) will not work reliably, with results varying either based on the number of features drawn.

1. Open the test confused.qgs project (download it here: http://www.licadho-cambodia.org/confused.zip)
2. Right click on ‘testing’ layer, and select “zoom to layer”
3. Let it render, and count the number of red polygons in the cluster of polygons to the right (here, it’s 4 – see wrong screenshot below)
4. Pan the canvas to totally hide the cluster of polygons to the left
5. Let it render, and count the number of red polygons (here, it’s 3 – see correct screenshot below)

I have no idea why the aggregation expression gets confused and give two different result (one clearly wrong). This should be addressed so this feature can be relied upon with fear of wrong results :)

Screenshots
Wrong:

Correct: