QGIS » QGIS Application

The EXP_FILTER parameter is evaluated only querying the layer fields with the basic operators (">", "<", "=", "LIKE", etc.)
The filter doesn't work using QGIS expressions.

Examples of WFS requests where the expressions are evaluated:

• http://...?service=WFS&request=GetFeature&...&EXP_FILTER="fieldA">10
• http://...?service=WFS&request=GetFeature&...&EXP_FILTER="fieldA">10 AND "fieldB"<=100
• http://...?service=WFS&request=GetFeature&...&EXP_FILTER="fieldC" LIKE 'demo'

Examples of WFS requests where the expressions are NOT evaluated:

• http://...?service=WFS&request=GetFeature&...&EXP_FILTER=area($geometry)>100
• http://...?service=WFS&request=GetFeature&...&EXP_FILTER=contains($geometry, geom_from_wkt('...'))
• http://...?service=WFS&request=GetFeature&...&EXP_FILTER=intersects($geometry, geom_from_gml('...'))
• http://...?service=WFS&request=GetFeature&...&EXP_FILTER="fieldA"=concat('...','...')

Tested with QGIS 3.4.3 and QGIS 3.5(master).
The issue occurs both with WFS 1.0.0 and WFS 1.1.0.

It's a regression since the same requests on the same projects/layers published with QGIS Server 2.18 work as expected.