Open pvalsecc opened 7 years ago
@rldhont, @rouault, an opinion on that? Anybody else to ask?
+1 Supporting OGC filter syntax in addition to the datasource syntax will be a plus
+1 This will also need an enhancement in QgsVectorLayer or QgsMapSettings to defined filter based on expression for rendering.
ping @pblottiere too
@pvalsecc Thank you for this feature. Does filter accept GML version 3?
QGIS Enhancement: Add support for OGC Filter Encoding to WMS
Date 2017/09/21
Author Patrick Valsecchi
Contact patrick.valsecchi@camptocamp.com
maintainer @pvalsecc
Version QGIS 3.0
Summary
The current WMS filter mechanism provided by QGIS is limited to QGIS specific expressions. This QEP proposes to add support of OGC Filter Encoding, following the same parameter format as MapServer and GeoServer.
Proposed Solution
Add another format for the WMS FILTER parameter that follows the current MapServer/GeoServer “standard”:
In the code handling the WMS format parameter, if the value starts with
“(<”
or with“<”
(both starting strings not possible with the current format), we split the filters for the different layers and generate theQgsFeatureRequest
from the XML, usingQgsWfs::parseFilterElement
(moving this function toQgsOgc
or something).The answer to GetCapabilities from MapServer doesn’t contain any reference to the filtering. So no change there.
Example(s)
See http://mapserver.org/development/rfc/ms-rfc-118.html
Affected Files
Performance Implications
Should have no impact on queries using the current filter format and the performance should be similar for the OGC Filter Encoding format.
Backwards Compatibility
No problem there. The old format will still be supported.
Votes
(required)