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<p>Hi!</p>
<p>To potentially improve our spatial filtering plugin <a
class="moz-txt-link-freetext"
href="https://plugins.qgis.org/plugins/spatial_filter/">https://plugins.qgis.org/plugins/spatial_filter/</a>
I am trying to figure out what is actually possible in QGIS in
terms of spatial filtering of OAPIF and WFS layers via layer.<span
class="sig-name descname"><span class="pre">setSubsetString</span></span><span
class="sig-paren">(...)</span>.</p>
<p><a
href="https://qgis.org/pyqgis/master/core/QgsVectorLayer.html#ogc-api-features-data-provider-oapif"
class="moz-txt-link-freetext">https://qgis.org/pyqgis/master/core/QgsVectorLayer.html#ogc-api-features-data-provider-oapif</a>
says</p>
<p>> 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.</p>
<p>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.</p>
<p>- Does "QGIS Expression list" refer to the list of QGIS
expression functions and variables, visible e.g. in a Field
Calculator dialog?</p>
<p>- Could someone name some example functions that one could use
with a standard OAPIF server for server-side filtering?<br>
</p>
<p>
</p>
<p>Thanks!<br>
Hannes</p>
<p><br>
</p>
<p>PS:<br>
I have some strong suspicion that this line actually belongs to
the WFS provider as it was originally written in the WFS section
in
<a class="moz-txt-link-freetext" href="https://github.com/qgis/QGIS/commit/920253d17d1b109e47d3698f989a3d85a40054eb#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455aR209">https://github.com/qgis/QGIS/commit/920253d17d1b109e47d3698f989a3d85a40054eb#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455aR209</a>
and only got moved to the OAPIF section by Even's commit in
<a class="moz-txt-link-freetext" href="https://github.com/qgis/QGIS/commit/c7f29d501fde79d01776e0f891255199493ed88f#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455a">https://github.com/qgis/QGIS/commit/c7f29d501fde79d01776e0f891255199493ed88f#diff-6e6383cd3adade52942c25186b2cf9985625fe338cadd3601a19467665eb455a</a></p>
<p>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.<br>
</p>
PPS: Potentially related bug report
<a class="moz-txt-link-freetext" href="https://github.com/qgis/QGIS/issues/60092">https://github.com/qgis/QGIS/issues/60092</a><br>
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