Hi Robb,
Thanks for your feedback. Some comments inline.
Rob Cermak wrote:
> Works great. Only a few comments:
>
> The WMS service emits more error messages if you try to feed it bad
> arguments (ie. REQUEST=GetMap)
That shouldn't be a bad argument. The parameter names are not
case-sensitive but the parameter values are (strangely enough) according
to the WMS 1.3.0 spec (Section 6.8.1 "Parameter ordering and case").
In the WCS we fudge on that and ignore case on the value as well as the
name. Looks like the WMS does the same as I'm not getting an error
message when I change the capitalization of the "request" parameter name
or value on a WMS request.
> vs. the WCS service. The WCS service
> silently fails by not emitting an error message or file. Do something
> bold like changing the version number from 1.0.0 to 9.0.0:
>
>
http://localhost:8080/thredds/wcs/testAll/2004050300_eta_211.nc?request=GetCoverage&version=9.0.0&service=WCS&format=GeoTIFF&coverage=Z_sfc&bbox=-134,11,-47,57
>
> This causes a silent failure. This makes for rough debugging of clients.
I get a 400 (Bad Request) response code with the following response body:
<?xml version="1.0" encoding="UTF-8"?>
<ServiceExceptionReport xmlns="http://www.opengis.net/ogc";
version="1.2.0">
<ServiceException code="InvalidParameterValue" locator="Version">
Invaled "Version" parameter value [9.0.0].
</ServiceException>
</ServiceExceptionReport>
Is this not what you are seeing?
If not, my guess is that some of my recent changes didn't quite make it
in the released version. They are in SVN and so will be in the next release.
> Changing the version in WMS from 1.3.0 to 4.3.0 causes a 404 error.
>
>
http://localhost:8080/thredds/wms/testAll/2004050300_eta_211.nc?service=WMS&version=4.3.0&request=GetCapabilities
Hmm. I thought we had gotten some version negotiation improvements into
the code that should have returned, in this case, a highest supported
version (1.3.0) response for this request. I'll check into this.
> This generates the desired error message:
>
>
http://localhost:8080/thredds/wms/testAll/2004050300_eta_211.nc?service=WMS&version=1.3.0&request=GetMap&layers=Z_sfc&crs=EPSG:4326&bbox=-135,19,-31,60&width=-50&height=400&styles=&format=image%2Fpng
>
> <ServiceExceptionReport version="1.3.0"
> xsi:schemaLocation="http://www.opengis.net/ogc
> http://schemas.opengis.net/wms/1.3.0/exceptions_1_3_0.xsd";>
>
> <ServiceException>
>
> Parameter WIDTH must be a valid positive integer
>
> </ServiceException>
> </ServiceExceptionReport>
With a 200 OK HTTP response code. Is that what we all expect here? The
WCS spec doesn't specify HTTP response codes and from a quick look it
doesn't look like the WMS spec does either.
A lot of implementations seem to always respond with a 200 (OK) code,
even when an exception report is being returned. That seems to make the
response code useless. Any thoughts on response codes?
> Can still get a map if you change the service name to something arbitrary:
>
>
http://localhost:8080/thredds/wms/testAll/2004050300_eta_211.nc?service=YES&version=1.3.0&request=GetMap&layers=Z_sfc&crs=EPSG:4326&bbox=-135,19,-31,60&width=600&height=400&styles=&format=image%2Fpng
I'm a bit torn here as the "/thredds/wms/" in the URL path already
indicates that it should be a WMS request. And we tend to be a bit
lenient in interpreting the request if it is clear what is intended.
> Anyways- using a well behaving client, this is all moot. Unfortunately,
> there is much variation between clients and versions they support.
>
> Rob
Thanks,
Ethan
--
Ethan R. Davis Telephone: (303) 497-8155
Software Engineer Fax: (303) 497-8690
UCAR Unidata Program Center E-mail: edavis@xxxxxxxx
P.O. Box 3000
Boulder, CO 80307-3000 http://www.unidata.ucar.edu/
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