[QGIS-Developer] Inserting provider filter just before PostGIS layer is loaded?

[Jacky Volpes]

Hi,

I don't know any way to do this, except for using a workaround.
But it will depend on your use-case.
Maybe using query layers, such as

QgsVectorLayer("table='(select * from <schema>.<table> <your 
conditions>)' service='<service>' key='<unique id column>'", "<table 
name>", "postgres")

can help ?

Regards,
Jacky



Le 09/08/2022 à 11:15, Johannes Kröger (WhereGroup) via QGIS-Developer a 
écrit :
> Howdy!
>
> I'd like to force a provider filter when a user adds a PostGIS layer 
> and have it applied *before* any data is loaded. Setting it after the 
> layer (and some of its big data) is loaded initially is not an option.
>
> Is there a way to sneak in between "user clicked something in the GUI 
> to load a table/query and QGIS will construct a QgsVectorLayer now" 
> and "QGIS now talks to the PostGIS database to get the data for the 
> new layer", maybe with a signal?
>
> Something like a "layerAboutToBeLoaded" (like the opposite 
> layerWillBeRemoved on 
> https://qgis.org/pyqgis/master/core/QgsProject.html) basically. :o)
>
> Cheers, Hannes
>
>
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-- 
Jacky Volpes

Ingénieur SIG - Oslandia
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