[QGIS-Developer] OGC API Features provider

[Stefan Keller]

Dear Even (dear Richard, dear all)

Many thanks for your replies. Thanks to your instant feedback we got
our minimal server implementation to work (also with QGIS).

Our issue was with the "/collections/castles/items" endpoint, where we
missed to include a link to the next page so that the (QGIS) reader
client can iterate through all the features pageuntil they’re all
read.

Finally, did I understood you correctly regarding the QGIS client options:

At 10. Dec. 2019 20:48 Even Rouault wrote:
> > Question 1: Any idea what QGIS makes it's OGC-API-Features reader to
> > add limit=10?
>
> Because that's the page size it detects from your service, or more presumably
> the default value if your service doesn't implement /api properly. You can
> tune it in the "WFS option" group of the "Modify WFS connection" dialog

I've added the WFS3 (alias OGC API-F) service using QGIS menu item
"Add Vector Layer..." in menu "Layer".
So you are referring to entry field "Request step size" in the "Data
Soure Manager WMS/WMTS dialog?

:Stefan

[1] https://pro.arcgis.com/en/pro-app/help/data/services/use-wfs-services.htm


Am Di., 10. Dez. 2019 um 20:48 Uhr schrieb Even Rouault
<even.rouault at spatialys.com>:
> > Question 1: Any idea what QGIS makes it's OGC-API-Features reader to
> > add limit=10?
>
> Because that's the page size it detects from your service, or more presumably
> the default value if your service doesn't implement /api properly. You can
> tune it in the "WFS option" group of the "Modify WFS connection" dialog


Am Di., 10. Dez. 2019 um 20:48 Uhr schrieb Even Rouault
<even.rouault at spatialys.com>:
>
> On mardi 10 décembre 2019 20:36:22 CET Stefan Keller wrote:
> > Hi,
> >
> > As I already talked about elsewhere I'm implementing a "minimal OGC-API
> > Features Server".
> >
> > Now I'd like to test this service with QGIS as client. And I also
> > tested QGIS with the "kataster" service [1] the mentioned in the docs
> > [2].
> > Unfortunately I count not get both services to work (display) in QGIS.
> >
> > * Our own service is being asked by QGIS with bbox and "limit=10&" any
> > time a zoom or pan occurs. But QGIS displays just 10 which are not
> > replaced by others whatever I do with QGIS.
>
> Perhaps your service doesn't really return true unique ids ?
>
> > * The kataster service asks about the CRS, then reports a large number
> > of features (which means there must be a different "limit="), and
> > finally does not answer requests from QGIS anymore.
>
> Works for me.
>
> >
> > Question 1: Any idea what QGIS makes it's OGC-API-Features reader to
> > add limit=10?
>
> Because that's the page size it detects from your service, or more presumably
> the default value if your service doesn't implement /api properly. You can
> tune it in the "WFS option" group of the "Modify WFS connection" dialog
>
> >
> > Question 2: Does anybody know about any another OGC-API Features
> > service we could use to test?
>
> See list in comment of https://github.com/qgis/QGIS/pull/32262
>
> Even
>
> --
> Spatialys - Geospatial professional services
> http://www.spatialys.com