WFS POST requests: "No template provided" error

Thu Nov 8 10:20:10 EST 2007

Try adding SERVICE=WFS to the URL of your POST request. MapServer needs 
at least something in the URL itself to be able to tell that it's a WFS 
request, otherwise it assumes by default that it is a traditional 
mapserv CGI request, hence the "no template provided" error.

I am realizing just now that it may not be correct according to the WFS 
spec to require that WFS clients include the SERVICE=WFS GET parameter 
in the case of POST requests. If that's the case then perhaps you could 
file a ticket to have this fixed in future releases of Mapserver. The 
simple fix would be for MapServer to automatically include the 
SERVICE=WFS in the onlineresource advertized in GetCapabilities and hten 
clients would pick it up automatically.

Daniel

Frank Steggink wrote:
> Hello List,
> 
> While developing a WFS client, I've encountered a problem with MapServer. I don't have a local setup of MapServer running, but use a few public available services at the web. Those are:
> *	http://map.ns.ec.gc.ca/MapServer/mapserv.exe?map=/mapserver/services/envdat/config.map (MapServer 4.8.3)
> *	http://www.bsc-eoc.org/cgi-bin/bsc_ows.asp (MapServer 4.8.1)
> 
> Our WFS client supports both GET and POST requests. It checks the Capabilities document which HTTP method to use. The document of the first service can be found here: http://map.ns.ec.gc.ca/MapServer/mapserv.exe?map=/mapserver/services/envdat/config.map&SERVICE=WFS&VERSION=1.0.0&REQUEST=GetCapabilities&. GetCapabilities is always done with GET, but other requests can vary. For testing purposes I made POST the default HTTP method for the requests. When I try to do a DescribeFeatureType or a GetFeature to these services with POST, I'm getting the following message:
> 
> <HTML>
> <HEAD><TITLE>MapServer Message</TITLE></HEAD>
> <!-- MapServer version 4.8.3 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP OUTPUT=PDF OUTPUT=SWF OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=THREADS SUPPORTS=GEOS INPUT=JPEG INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE DEBUG=MSDEBUG -->
> <BODY BGCOLOR="#FFFFFF">
> mapserv(): Web application error. No template provided. <br>
> </BODY></HTML>
> 
> The Capabilites document lists the online resource URL's for DescribeFeatureType and GetFeature, so POST should be allowed for these WFS requests. I'm sure that the WFS request is correct, since it works with other WFS servers, like Geoserver, and Oracle Spatial Web Services, and I can not find anything that might be wrong on my side. Here is the raw request (headers + post data):
> 
> POST /envdat/map.aspx HTTP/1.1
> Content-Type: text/xml
> Host: map.ns.ec.gc.ca
> Content-Length: 579
> Expect: 100-continue
> Proxy-Connection: Close
> 
> <?xml version="1.0" encoding="iso-8859-1"?>
> <DescribeFeatureType version="1.0.0" service="WFS" xsi:schemaLocation="http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.0.0/WFS-basic.xsd" xmlns="http://www.opengis.net/wfs" xmlns:b="http://www.bentley.com/schemas/x-Bentley.XMLTemplate.0.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ows="http://www.opengis.net/ows" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
>   <TypeName>wfs:envirodat</TypeName>
> </DescribeFeatureType>
> 
> While searching the mailing list, I found replies of people suggesting that WFS might not be enabled (MapServer not compiled with WFS support), but since WFS requests with GET work fine, this is obviously not the case. I also found another suggestion here: http://lists.umn.edu/cgi-bin/wa?S2=MAPSERVER-USERS&q=wfs+post+template&s=&f=&a=&b=. It is suggested to add the parameters "service=WFS" and "version=1.0.0" to the URL for POST, but this doesn't work either. Maybe I would need to test with a more recent build, but I couldn't find one at the web. But this would mean that I have to change the online resource URL, but the correct URL cannot be predicted. The correct URL to post to should be mentioned in the Capabilities document. The second service (www.bsc-eoc.org) returned the same reply with the parameters, but the first service (at map.ns.ec.gc.ca) returned this:
> 
> <ServiceExceptionReport
> xmlns="http://www.opengis.net/ogc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/ogc http://schemas.opengis.net/wms/1.1.1/OGC-exception.xsd">
>   <ServiceException>
> msWFSDispatch(): WFS server error. Incomplete WFS request: REQUEST parameter missing
>   </ServiceException>
> </ServiceExceptionReport>
> 
> If I would add the Request parameter, then it would be WFS / GET again, and that's not what I want. (Well, I normally do, but this is for testing purposes.)
> I was getting similar responses with GetFeature, but since I changed my code, the WFS client doesn't come that far (because DescribeFeatureType doesn't work) anymore. 
> 
> Since there are no problems with GET requests, our client can successfully query data. But since POST is also available, I would expect it to work as well. I hope that someone can look into this. If POST really causes problems, it would be better to remove the associated online resource URL's from the Capabilities document.
> 
> Regards,
> 
> Frank Steggink
>  
> Bentley Systems, Inc.
> Software Developer Geospatial
>  
> 3645, boul. Ste-Anne
> Québec, Qc. G1E 3L1
> Canada
>  
> Tel: +1 418 666 7691 ext. 289
> E-mail: frank.steggink at bentley.com
> WWW: http://www.bentley.com
>  

-- 
Daniel Morissette
http://www.mapgears.com/