[iso19139:2007] add more generic char/anchor check

[pvgenuchten]

Anchor is used in quite places in the inspire profile on iso19139:2007

Add xxx_url property to keep backwards compatibility

Adds tests based on a record, derived from nationaalgeoregister.nl

[coveralls]

coverage: 60.203% (+0.05%) from 60.156%
when pulling a0e2029 on pvgenuchten:evaluate_anchor_generic
into ae98c20 on geopython:master.

[geographika]

@pvgenuchten - do you have a link to the raw XML used as the basis for your test record?

It may also be good to just add the XML snippet that this pull request is solving (with and without a /gmx:Anchor).

The code looks good to me, but I've no experience with iso19139:2007. Will leave open for comment for a couple of weeks prior to merging.

[pvgenuchten]

updated method text

raw xml is at
https://www.nationaalgeoregister.nl/geonetwork/srv/metadata/f44dac86-2228-412f-8355-e56446ca9933/formatters/xml

a thing i would like your view on is this: if a list consists of charstring, anchor, charstring, anchor, would you expect:

{
name: [foo,la,lo,li]
url: [http://la,http:li]
}

or

{
name: [foo,la,lo,li]
url: [None,http://la,None,http:li]
}

[pvgenuchten]

Yes, I can see the point of not exposing such real life metadata as part of a software, on the other side it is an indication of the fact that these patterns are used in the wild…

[geographika]

updated method text

raw xml is at https://www.nationaalgeoregister.nl/geonetwork/srv/metadata/f44dac86-2228-412f-8355-e56446ca9933/formatters/xml

a thing i would like your view on is this: if a list consists of charstring, anchor, charstring, anchor, would you expect:

{
name: [foo,la,lo,li]
url: [http://la,http:li]
}

or

{
name: [foo,la,lo,li]
url: [None,http://la,None,http:li]
}

I'd imagine it would be expected the name and URL list lengths would match, although not sure about use of None. An empty string may be better in this case?

@pvgenuchten do you have an example of the above from the XML you linked to that I could test the above question with?
I've tested the branch and new properties with the following Python:

>>> from owslib.iso import *
>>>
>>> md = MD_Metadata(etree.parse('test.xml'))
>>> iden = md.identification[0]
>>> iden.contact[0].organization_url
'http://standaarden.overheid.nl/owms/terms/Ministerie_van_Defensie'
>>> iden.contact[0].name_url
''
>>> iden.contact[0].name
'Ministerie van Defensie, Koninklijke Marine, Dienst der Hydrografie'
>>> iden.otherconstraints
['Geen beperkingen', 'Er zijn geen condities voor toegang en gebruik', 'Geen beperkingen voor publieke toegang']

>>> dist = md.distribution
>>> dist.specification_url
'http://inspire.ec.europa.eu/id/document/tg/hy'

[pvgenuchten]

updated PR to have matching lengths of xx vs xx_url

combined use is available in

OWSLib/tests/resources/csw_dov_getrecordbyid.xml

Lines 470 to 475 in ae98c20

	<gmd:otherConstraints>
	<gco:CharacterString>Data beschikbaar voor hergebruik volgens de Modellicentie Gratis Hergebruik. Toelichting beschikbaar op https://www.dov.vlaanderen.be/page/gebruiksvoorwaarden-dov-services</gco:CharacterString>
	</gmd:otherConstraints>
	<gmd:otherConstraints>
	<gmx:Anchor xlink:href="https://inspire.ec.europa.eu/metadata-codelist/ConditionsApplyingToAccessAndUse/noConditionsApply">Geen beperkingen</gmx:Anchor>
	</gmd:otherConstraints>

another sample in the wild is this one

https://www.nationaalgeoregister.nl/geonetwork/srv/api/records/1e9cf0ef-f905-46df-b4f8-2bab7a3808bb/formatters/xml