[QGIS-Developer] Spatial filtering of OAPIF layers

[Johannes Kröger (WhereGroup)]

Hi!

To potentially improve our spatial filtering plugin 
https://plugins.qgis.org/plugins/spatial_filter/ I am trying to figure 
out what is actually possible in QGIS in terms of spatial filtering of 
OAPIF and WFS layers via layer.setSubsetString(...).

https://qgis.org/pyqgis/master/core/QgsVectorLayer.html#ogc-api-features-data-provider-oapif 
says

 > You can use various functions available in the QGIS Expression list, 
however the function must exist server side and have the same name and 
arguments to work.

Those filters are a complex setup around QGIS expressions, SQL queries 
and automatic OGC/FES filter conversion and I am currently too dumb to 
figure out what this actually means.

- Does "QGIS Expression list" refer to the list of QGIS expression 
functions and variables, visible e.g. in a Field Calculator dialog?

- Could someone name some example functions that one could use with a 
standard OAPIF server for server-side filtering?

Thanks!
Hannes


PS:
I have some strong suspicion that this line actually belongs to the WFS 
provider as it was originally written in the WFS section in 
https://github.com/qgis/QGIS/commit/920253d17d1b109e47d3698f989a3d85a40054eb#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455aR209 
and only got moved to the OAPIF section by Even's commit in 
https://github.com/qgis/QGIS/commit/c7f29d501fde79d01776e0f891255199493ed88f#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455a

If that is the case then I would still be interested in examples for 
WFS, instead of OAPIF, and to know what the documentation should read 
instead for server-side(!) filtering of OAPIF.

PPS: Potentially related bug report 
https://github.com/qgis/QGIS/issues/60092
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-developer/attachments/20250109/063e42f7/attachment.htm>