[mapserver-users] WFS Client returns data at random with very same call

Fri May 28 05:32:42 PDT 2021

Lars,

I believe the service you request doesn't implement WFS 1.1 properly.

Trying this

./mapserv 
QUERY_STRING="map=wfs.map&SRSNAME=EPSG:3857&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&BBOX=791880.72463009,6321925.37255709,792929.63787777,6322786.10157277&TYPENAME=TestLayer" 

I see that GDAL does:

VSICURL: Start download for 
http://sg.geodatenzentrum.de/wfs_info?SERVICE=WFS&VERSION=1.1.0&MAXFEATURES=500&REQUEST=GetFeature&TYPENAME=info:dop&FILTER=%3CFilter%20xmlns%3D%22http:%2F%2Fwww.opengis.net%2Fogc%22%20xmlns:gml%3D%22http:%2F%2Fwww.opengis.net%2Fgml%22%3E%3CBBOX%3E%3CPropertyName%3Egeom%3C%2FPropertyName%3E%3Cgml:Box%3E%3Cgml:coordinates%3E362792.2015953020309098,5459899.7109905285760760%20363491.4383923375280574,5460477.4964771848171949%3C%2Fgml:coordinates%3E%3C%2Fgml:Box%3E%3C%2FBBOX%3E%3C%2FFilter%3E

So Mapserver has transmitted to GDAL a BBOX filter in epsg:25832 (which 
is the native SRS of the layer) that is the reprojection of your source 
BBOX from EPSG:3857. All things are good up to that point.

But the server returns an empty response.

Tweaking it manually to include a srsName="EPSG:25832" attribute in 
gml:Box returns a response with 2 features

http://sg.geodatenzentrum.de/wfs_info?SERVICE=WFS&VERSION=1.1.0&MAXFEATURES=500&REQUEST=GetFeature&TYPENAME=info:dop&FILTER=%3CFilter%20xmlns%3D%22http:%2F%2Fwww.opengis.net%2Fogc%22%20xmlns:gml%3D%22http:%2F%2Fwww.opengis.net%2Fgml%22%3E%3CBBOX%3E%3CPropertyName%3Egeom%3C%2FPropertyName%3E%3Cgml:Box%20srsName=%22EPSG:25832%22%3E%3Cgml:coordinates%3E362792.2015953020309098,5459899.7109905285760760%20363491.4383923375280574,5460477.4964771848171949%3C%2Fgml:coordinates%3E%3C%2Fgml:Box%3E%3C%2FBBOX%3E%3C%2FFilter%3E

But we shouldn't have to do this has a missing srsName should be 
interpretated as the defaultSRS according to my understand of the WFS 
1.1 spec

You can however tweak the <URL> element in wfs-request-dop-bkg-age and 
add "&SRSNAME=EPSG:25832" to it (since it is the defaultSRS of all 
the layers of the service), and then GDAL will forward it.

Even

Le 28/05/2021 à 14:11, Lars Fricke a écrit :
> No problem. Unfortunately, testing native WFS did not work because it 
> does not properly support cascading wfs with different srs (see my 
> other post).
>
> Thanks for looking into this.
> SkenData Email Signatur
>
> Am 28.05.21 um 13:55 schrieb Even Rouault:
>>
>> oops, sorry, didn't notice 😅
>>
>> Le 28/05/2021 à 13:52, Lars Fricke a écrit :
>>> I put in the files as attach. Is that filtered?
>>> SkenData Email Signatur
>>>
>>> Am 28.05.21 um 13:43 schrieb Even Rouault:
>>>>
>>>> Please include your mapfile and the wfs-request-testlayer.xml file 
>>>> to reproduce. I'm confused by the mapfile you posted yesterday that 
>>>> uses epsg:25832 and the fact that GDAL through mapserver would 
>>>> issue a GetFeature in EPSG:3857 as suggested below. I can't see how 
>>>> that could happen (given the MapServer/GDAL integration, GDAL 
>>>> should always request in the native SRS of the layer and MapServer 
>>>> will do the reprojection to the SRSNAME of the WFS request)
>>>>
>>>> But as Daniel suggested using the CONNECTION WFS is probably a 
>>>> better way of doing what you want
>>>>
>>>> Le 28/05/2021 à 13:13, Lars Fricke via mapserver-users a écrit :
>>>>> So here is the working not working setup. Unfortunately the 
>>>>> working OGR WFS client layers are all private so I can not share them.
>>>>>
>>>>> This call delivers objects as expected:
>>>>> http://localhost:8181/cgi-bin/mapserv?map=/var/www/html/wfs.map&SRSNAME=EPSG:3857&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&Maxfeatures=10&TYPENAME=TestLayer
>>>>> This one, too:
>>>>> http://localhost:8181/cgi-bin/mapserv?map=/var/www/html/wfs.map&SRSNAME=EPSG:3857&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&Maxfeatures=10&TYPENAME=TestLayer
>>>>>
>>>>> Data is delivered in the correct srs (verified manually with QGIS).
>>>>>
>>>>> This call doesn't work as described before as BBOX is not 
>>>>> transmitted to external server:
>>>>> http://localhost:8181/cgi-bin/mapserv?map=/var/www/html/wfs.map&SRSNAME=EPSG:3857&SERVICE=WFS&VERSION=1.0.0&REQUEST=GetFeature&BBOX=791880.72463009,6321925.37255709,792929.63787777,6322786.10157277&TYPENAME=TestLayer
>>>>>
>>>>> While the same direct call works:
>>>>> http://sg.geodatenzentrum.de/wfs_info?SRSNAME=EPSG:3857&SERVICE=WFS&VERSION=1.0.0&REQUEST=GetFeature&BBOX=791880.72463009,6321925.37255709,792929.63787777,6322786.10157277&TYPENAME=info:dop
>>>>> (funny, epsg 3857 is not in the capabilities but works anyhow)
>>>>>
>>>>> I hope you can find out what is going wrong. Thanks so much for 
>>>>> looking into this!
>>>>>
>>>>> Best
>>>>>
>>>>> Lars
>>>>> SkenData Email Signatur
>>>>>
>>>>>
>>>>> Am 27.05.21 um 18:28 schrieb Rahkonen Jukka (MML):
>>>>>> SkenData Email Signatur
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Have you already tried to use WFS connection instead of OGR 
>>>>>> connection?
>>>>>>
>>>>>> -Jukka Rahkonen-
>>>>>>
>>>>>> *Lähettäjä:* mapserver-users 
>>>>>> <mapserver-users-bounces at lists.osgeo.org> *Puolesta *Lars Fricke
>>>>>> *Lähetetty:* torstai 27. toukokuuta 2021 14.59
>>>>>> *Vastaanottaja:* mapserver-users at lists.osgeo.org
>>>>>> *Aihe:* Re: [mapserver-users] WFS Client returns data at random 
>>>>>> with very same call
>>>>>>
>>>>>> Dear all,
>>>>>> I apologize for finding and posting bits and pieces not all at 
>>>>>> one time.
>>>>>> I fired up 'CONFIG "CPL_DEBUG" "ON"' and there I see, that
>>>>>> """
>>>>>>
>>>>>> HTTP: 
>>>>>> Fetch(http://url-to-external-server?SERVICE=WFS&VERSION=1.1.0&MAXFEATURES=1000&REQUEST=GetFeature&TYPENAME=dop 
>>>>>> <http://url-to-external-server?SERVICE=WFS&VERSION=1.1.0&MAXFEATURES=1000&REQUEST=GetFeature&TYPENAME=dop>)
>>>>>> """
>>>>>> So there is no BBOX. On other layers I see
>>>>>> """
>>>>>> GDALOpen(/vsicurl_streaming/https:...
>>>>>> """
>>>>>> with BBOX.
>>>>>> No wonder I do not get reliable results if the server is calling 
>>>>>> some 1000 whatsoever result objects and starts filtering the bbox 
>>>>>> after.
>>>>>>
>>>>>> Any idea what is happening? Or is this something for a GDAL thread?
>>>>>>
>>>>>> Best
>>>>>> Lars
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> mapserver-users mailing list
>>>>> mapserver-users at lists.osgeo.org
>>>>> https://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>> -- 
>>>> http://www.spatialys.com
>>>> My software is free, but my time generally not.
>>>
>> -- 
>> http://www.spatialys.com
>> My software is free, but my time generally not.
>
-- 
http://www.spatialys.com
My software is free, but my time generally not.

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