[OWSLib-devel] nextRecord missing

[David Read]

Great, I've done both of these suggestions and submitted a pull request:

https://github.com/geopython/OWSLib/pull/101

David

On 22 October 2013 13:21, Tom Kralidis <tomkralidis at gmail.com> wrote:
>
>
> On Tue, 22 Oct 2013, David Read wrote:
>
>> Date: Tue, 22 Oct 2013 13:10:52 +0100
>> From: David Read <david.read at hackneyworkshop.com>
>> To: Tom Kralidis <tomkralidis at gmail.com>
>> Cc: owslib-devel at lists.osgeo.org
>> Subject: Re: [OWSLib-devel] nextRecord missing
>>
>>
>> Thanks Tom. I've opened the issue and will submit a pull request,
>> including the test.
>>
>> Yes, "nextrecord: None" would mean the element did not exist, unless
>> you think the key should not be returned at all?
>>
>
> This would result in a KeyError, which IMHO may prove brittle given
> the usage of owslib.csw out there.
>
>
>> Is there some documentation or something where we can warn OWSLib
>> clients to not rely on the nextRecord value existing?
>>
>
> Maybe along with setting nextrecord to None
> we can also do a warnings.warn to say this? At least it will catch in
> downstream Python logs, then?
>
>
>> David
>>
>> On 22 October 2013 12:50, Tom Kralidis <tomkralidis at gmail.com> wrote:
>>>
>>>
>>>
>>> On Tue, 22 Oct 2013, David Read wrote:
>>>
>>>> Date: Tue, 22 Oct 2013 12:33:37 +0100
>>>> From: David Read <david.read at hackneyworkshop.com>
>>>> To: owslib-devel at lists.osgeo.org
>>>> Subject: [OWSLib-devel] nextRecord missing
>>>>
>>>>
>>>> Have any of you encountered a CSW Server that doesn't give a
>>>> nextRecord value when doing a GetRecords request? I'm using OWSLib to
>>>> talk to it and it gives an exception and I have a patch I can push
>>>> that'll avoid the exception. But is that what we want it to do?
>>>>
>>>> The server is running "Conterra sdi.suite". Apparently Conterra's view
>>>> is that it is best practice for the client to keep track of where it
>>>> is up to, and not to rely on the server, and so they adhere to the XSD
>>>> schema rather than the guidance on this particular issue.
>>>>
>>>> The schema http://schemas.opengis.net/csw/2.0.2/CSW-discovery.xsd says
>>>> it is OPTIONAL:
>>>>
>>>> <xsd:attribute name="nextRecord" type="xsd:nonNegativeInteger"
>>>> use="optional"/>
>>>>
>>>> yet the spec it claims to reflect says it is REQUIRED:
>>>>
>>>> http://portal.opengeospatial.org/files/?artifact_id=21460
>>>>
>>>> <xsd:attribute name="nextRecord"
>>>>                     type="xsd:nonNegativeInteger"
>>>>                              use="required"/>
>>>>
>>>> Is the XSD (and therefore Conterra) simply wrong? Or is this
>>>> justifiable?
>>>>
>>>
>>> Unfortunately, D.1.1 of the spec says:
>>>
>>> "In the event of a discrepancy between the bundled and online versions of
>>> the
>>> XML Schema files, the online files shall be considered authoritative."
>>>
>>> Though it would be really nice (and really easy) for the CSW server impl
>>> to
>>> support nextRecord.
>>>
>>> This will also trip up existing OWSLib clients who may be doing something
>>> with
>>> nextRecord already assuming it's an int?
>>>
>>> David: sure, submit a PR against master? It would be really really great
>>> also
>>> if you could provide a small test case in our doctests.
>>>
>>> example:
>>>
>>> https://github.com/geopython/OWSLib/blob/master/tests/doctests/csw_nlr.txt
>>>
>>>
>>>> BTW here's my patched version of OWSLib running:
>>>>
>>>>   >>> from owslib.csw import CatalogueServiceWeb as cs
>>>>   >>> c=cs('https://gateway.ceh.ac.uk/soapServices/CSWStartup')
>>>>   >>> c.version
>>>>    '2.0.2'
>>>>   >>> c.getrecords2()
>>>>   >>> c.results
>>>>    {'matches': 291, 'nextrecord': None, 'returned': 10}
>>>>
>>>
>>> So nextrecord: None would mean that the element did not exist, correct?
>>>
>>>> David
>>
>>
>