No. I am relying on the character sequence of a namespace URI to identify a
content model. Think of it as an opaque hash key that tells how to
interpret content that belongs to that namespace.
The example document specifies a default namespace, and uses unprefixed
element names. Consequently, PyXB needs to find a content model for an
element with expanded name {
http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader}GovTalkMessage.
You've only told it about
{http://www.govtalk.gov.uk/CM/envelope}GovTalkMessage.
Those are different elements.
I'm sorry, but this is not a PyXB problem.
Peter
On Wed, Oct 19, 2011 at 12:19 PM, Marcin Tustin <marcin.tus...@gmail.com>wrote:
> I do not see anything in http://www.w3.org/TR/REC-xml-names/ that suggests
> that the example document is incorrect. Once again, you seem to be relying
> on namespace URIs naming some kind of substantive resource.
>
>
> On Wed, Oct 19, 2011 at 18:11, Peter Bigot <big...@acm.org> wrote:
>
>> On Wed, Oct 19, 2011 at 12:03 PM, Marcin Tustin
>> <marcin.tus...@gmail.com>wrote:
>>
>>> In what sense is the document lying about its namespace? For it to be
>>> lying would require something substantive of the document that the namespace
>>> points to, no?
>>
>>
>> The presence of the following attribute:
>>
>> xmlns="http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader";
>>
>> says that any unprefixed element tag within the element should be assumed
>> to be part of the namespace with that URI. See
>> http://www.w3.org/TR/REC-xml-names/#defaulting.
>>
>> The document then goes on to use unprefixed tags like GovTalkMessage.
>> PyXB therefore needs to know the details of the schema for the namespace
>> http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader so it can
>> determine whether the content that the document provides for GovTalkMessage
>> is consistent with the structure associated with that element in the
>> namespace's content model.
>>
>> I suspect that the example document is simply wrong, and hope that the
>> live service provides valid documents.
>>
>> If you change the value of the xmlns attribute at the top of the document
>> as I suggested, and if the remainder of the example is a valid document
>> corresponding to the http://www.govtalk.gov.uk/CM/envelope namespace,
>> then PyXB will parse it.
>>
>> Please review http://www.w3.org/TR/REC-xml-names. The problem is with
>> the example document, not with PyXB.
>>
>> Peter
>>
>>
>>> On Wed, Oct 19, 2011 at 18:01, Peter Bigot <big...@acm.org> wrote:
>>>
>>>> On Wed, Oct 19, 2011 at 11:53 AM, Marcin Tustin <
>>>> marcin.tus...@gmail.com> wrote:
>>>>
>>>>> OK, how should I provide the schema to pyxb so that it can decode such
>>>>> documents? The XSD which I need my documents to conform to is the one from
>>>>> which I'm generating the code.
>>>>
>>>>
>>>> As far as I can tell, the schema isn't the problem. (You will have to
>>>> also locate the schema for and generate bindings for
>>>> http://www.govtalk.gov.uk/CM/core, since the envelope's schema
>>>> references types defined in that namespace.)
>>>>
>>>> The problem is the example document is lying about what namespace its
>>>> content conforms to. Change:
>>>>
>>>> <GovTalkMessage xmlns="
>>>> http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader";
>>>>
>>>> at the top of the document you're parsing to:
>>>>
>>>> <GovTalkMessage xmlns="http://www.govtalk.gov.uk/CM/envelope";
>>>>
>>>> Peter
>>>>
>>>> On Wed, Oct 19, 2011 at 17:46, Peter Bigot <big...@acm.org> wrote:
>>>>>
>>>>>> On Wed, Oct 19, 2011 at 11:22 AM, Marcin Tustin <
>>>>>> marcin.tus...@gmail.com> wrote:
>>>>>>
>>>>>>> Hi Peter,
>>>>>>>
>>>>>>> Thanks for this. Unless I'm mistaken, namespace URIs are not required
>>>>>>> to map to any resource at all, let alone an XSD. However, the xsd from
>>>>>>> which
>>>>>>> I'm generating the code is at
>>>>>>> http://xmlgw.companieshouse.gov.uk/v2-1/schema/Egov_ch-v2-0.xsd.
>>>>>>>
>>>>>>
>>>>>> That schema is for namespace http://www.govtalk.gov.uk/CM/envelope.
>>>>>>
>>>>>> What is PyXB expecting in its input that could be leading to this?
>>>>>>> Does it rely on namespaces naming XSD files?
>>>>>>>
>>>>>>
>>>>>> No, PyXB treats namespaces as URIs, not URLs, and has no expectation
>>>>>> that they can be dereferenced. (It may, when generating bindings, make
>>>>>> some
>>>>>> attempt to locate the schema from an xsi:schemaLocation attribute, but
>>>>>> that
>>>>>> shouldn't happen when parsing.)
>>>>>>
>>>>>> The example documents (from the link you provided) do not reference
>>>>>> the namespace http://www.govtalk.gov.uk/CM/
>>>>>> envelope. They both specify that the default namespace is
>>>>>> http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader. Unless you
>>>>>> have a schema for that namespace, PyXB won't be able to decode the
>>>>>> content
>>>>>> of the document.
>>>>>>
>>>>>> If the document doesn't specify a default namespace I believe it would
>>>>>> fall back to the one you used as the CreateFromDocument call, but when
>>>>>> the
>>>>>> document does specify a namespace it's expected to be correct.
>>>>>>
>>>>>> Try editing the document and correcting the xmlns= attribute at the
>>>>>> root so it has the same namespace as the module you're using to parse it.
>>>>>>
>>>>>> Peter
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> On Wed, Oct 19, 2011 at 16:49, Peter Bigot <big...@acm.org> wrote:
>>>>>>>
>>>>>>>> On Wed, Oct 19, 2011 at 10:32 AM, Marcin Tustin <
>>>>>>>> marcin.tus...@gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Hi all,
>>>>>>>>>
>>>>>>>>> I'm making my first contact with pyxb, and so far it seems to only
>>>>>>>>> exist to generate odd errors.
>>>>>>>>>
>>>>>>>>> I've tried to have it parse a document with:
>>>>>>>>>
>>>>>>>>> > import govtalkenvelope as g
>>>>>>>>> > g.CreateFromDocument("""[xml taken from
>>>>>>>>> http://xmlgw.companieshouse.gov.uk/example_http.html]""";)
>>>>>>>>> Traceback (most recent call last):
>>>>>>>>> File "<stdin>", line 35, in <module>
>>>>>>>>> File "govtalkenvelope.py", line 32, in CreateFromDocument
>>>>>>>>> saxer.parse(StringIO.StringIO(xml_text))
>>>>>>>>> File "C:\Python27\Lib\xml\sax\expatreader.py", line 107, in parse
>>>>>>>>> xmlreader.IncrementalParser.parse(self, source)
>>>>>>>>> File "C:\Python27\Lib\xml\sax\xmlreader.py", line 123, in parse
>>>>>>>>> self.feed(buffer)
>>>>>>>>> File "C:\Python27\Lib\xml\sax\expatreader.py", line 207, in feed
>>>>>>>>> self._parser.Parse(data, isFinal)
>>>>>>>>> File "C:\Python27\Lib\xml\sax\expatreader.py", line 338, in
>>>>>>>>> start_element_ns
>>>>>>>>> AttributesNSImpl(newattrs, qnames))
>>>>>>>>> File
>>>>>>>>> "C:\Users\Marcin\Documents\oneclickcos\lib\site-packages\pyxb\binding\sax
>>>>>>>>> er.py", line 310, in startElementNS
>>>>>>>>> element_binding = name_en.elementBinding()
>>>>>>>>> File
>>>>>>>>> "C:\Users\Marcin\Documents\oneclickcos\lib\site-packages\pyxb\namespace\_
>>>>>>>>> _init__.py", line 96, in __getattr__
>>>>>>>>> category_value =
>>>>>>>>> self.namespace().categoryMap(name).get(self.localName())
>>>>>>>>> File
>>>>>>>>> "C:\Users\Marcin\Documents\oneclickcos\lib\site-packages\pyxb\namespace\_
>>>>>>>>> _init__.py", line 293, in categoryMap
>>>>>>>>> raise pyxb.NamespaceError(self, '%s has no category %s' %
>>>>>>>>> (self, category))
>>>>>>>>> pyxb.exceptions_.NamespaceError:
>>>>>>>>> http://www.govtalk.gov.uk/schemas/govtalk/govta
>>>>>>>>> lkheader has no category elementBinding
>>>>>>>>>
>>>>>>>>
>>>>>>>> It's probably saying it doesn't know how to deal with the
>>>>>>>> http://www.govtalk.gov.uk/schemas/govtalk/govtalkheader namespace.
>>>>>>>> Certainly it isn't clear to me where to find a schema for that
>>>>>>>> namespace;
>>>>>>>> the xsiLocation URI in the sample resolves to a web page, not a schema.
>>>>>>>>
>>>>>>>> Did you generate bindings for that namespace? How?
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Needless to say, it's less than clear what this is supposed to
>>>>>>>>> mean. Any suggestions as to what might be causing this, or indeed how
>>>>>>>>> in
>>>>>>>>> general to deal with pyxb's exception messages?
>>>>>>>>>
>>>>>>>>
>>>>>>>> Experience is the only guide. Sorry, PyXB development is unfunded,
>>>>>>>> so making it user friendly hasn't gotten much attention.
>>>>>>>>
>>>>>>>> Peter
>>>>>>>>
>>>>>>>>
>>>>>>>>>
>>>>>>>>> Marcin
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> Marcin Tustin
>>>>>>>>> Tel: 07773 787 105
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> ------------------------------------------------------------------------------
>>>>>>>>> All the data continuously generated in your IT infrastructure
>>>>>>>>> contains a
>>>>>>>>> definitive record of customers, application performance, security
>>>>>>>>> threats, fraudulent activity and more. Splunk takes this data and
>>>>>>>>> makes
>>>>>>>>> sense of it. Business sense. IT sense. Common sense.
>>>>>>>>> http://p.sf.net/sfu/splunk-d2d-oct
>>>>>>>>> _______________________________________________
>>>>>>>>> pyxb-users mailing list
>>>>>>>>> pyxb-users@lists.sourceforge.net
>>>>>>>>> https://lists.sourceforge.net/lists/listinfo/pyxb-users
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
>>>>>>> Marcin Tustin
>>>>>>> Tel: 07773 787 105
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Marcin Tustin
>>>>> Tel: 07773 787 105
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Marcin Tustin
>>> Tel: 07773 787 105
>>>
>>>
>>
>
>
> --
> Marcin Tustin
> Tel: 07773 787 105
>
>
------------------------------------------------------------------------------
All the data continuously generated in your IT infrastructure contains a
definitive record of customers, application performance, security
threats, fraudulent activity and more. Splunk takes this data and makes
sense of it. Business sense. IT sense. Common sense.
http://p.sf.net/sfu/splunk-d2d-oct
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