Microsoft XML - 'selectSingleNode' returns NULL if XML-Data schema is assigned???

Author

'selectSingleNode' returns NULL if XML-Data schema is assigned???

Teis Draiby

2004-03-30, 10:13 pm

Why can't I use 'selectSingleNode' when a XML-Data schema is assigned my XML
document? (see XML #1). selectSingleNode returns NULL in this case.
BUT: selectSingleNode works fine if I remove the reference to the schema
(see XML #2).
I validated the XML file against the schema in XMLSPY.

Im using VC++ and MSXML 4.0

thank you very much, Teis

I use: ...selectSingleNode("//weather/degrees");

XML #1 with schema:
---------------------------------------
<?xml version="1.0"?>
<weather xmlns="x-schema:weatherSchema.xml">
<degrees>67.5</degrees>
</weather>

XML #2 without schema:
---------------------------------------
<?xml version="1.0"?>
<weather>
<degrees>67.5</degrees>
</weather>

Schema: "weatherSchema.xml"
---------------------------------------
<Schema xmlns="urn:schemas-microsoft-com:xml-data"
xmlns:dt="urn:schemas-microsoft-com:datatypes">
<ElementType name="degrees" content="textOnly" dt:type="float"/>
<ElementType name="weather" content="eltOnly">
<element type="degrees"/>
</ElementType>
</Schema>

Gohlool

2004-03-30, 10:13 pm

HIi!

If I am not wrong you have to use the followings:

there are 2 ways:

1) the correct way

using the XMLSchemaCache to add your schema to!

example:

SchemaCollection := CoXMLSchemaCache40.Create;
SchemaCollection.validateOnLoad := true;
SchemaCollection.add('', 'c:\weatherSchema.xml'); //the first Param. is the
prefix, but in your case you have no prefix defined.

and then
in you IXMLDomDocument2

XMLDoc.schemas := SchemaCollection;
XMLDoc.setProperty('NewParser', 'True');
XMLDoc.setProperty('SelectionLanguage', 'XPath');

then I think you will need the following:

XMLDoc.setProperty('SelectionNamespaces', NameSpaceList);

check the Help and you will see what is the SelectionNamespaces property is!

I think in your case it would be something like this

NameSpaceList := 'xmlns="urn:schemas-microsoft-com:xml-data" ';
Result.setProperty('SelectionNamespaces', NameSpaceList);

then you have to validate your xml

XMLDOc.validateOnParse := True;

and then try the your selectSingleNode("//weather/degrees"); again

I think this should help!

2) the simple hack. (because you don't have any other namespaces and tags
with the same name)

the other way is the following:

forget all what I wrote before:

now go to your code and instead of calling:

selectSingleNode("//weather/degrees");

call something like this:

SelectionString = "descendant::*[local-name()='//weather/degrees']";
selectSingleNode(SelectionString);

good luck!
Gohlool

"Teis Draiby" <teisREMOVE-THIS@draiby.com> wrote in message
news:OMSSjxSEEHA.3424@tk2msftngp13.phx.gbl...
> Why can't I use 'selectSingleNode' when a XML-Data schema is assigned my
XML
> document? (see XML #1). selectSingleNode returns NULL in this case.
> BUT: selectSingleNode works fine if I remove the reference to the schema
> (see XML #2).
> I validated the XML file against the schema in XMLSPY.
>
> Im using VC++ and MSXML 4.0
>
> thank you very much, Teis
>
>
>
> I use: ...selectSingleNode("//weather/degrees");
>
>
>
> XML #1 with schema:
> ---------------------------------------
> <?xml version="1.0"?>
> <weather xmlns="x-schema:weatherSchema.xml">
> <degrees>67.5</degrees>
> </weather>
>
>
>
> XML #2 without schema:
> ---------------------------------------
> <?xml version="1.0"?>
> <weather>
> <degrees>67.5</degrees>
> </weather>
>
>
>
> Schema: "weatherSchema.xml"
> ---------------------------------------
> <Schema xmlns="urn:schemas-microsoft-com:xml-data"
> xmlns:dt="urn:schemas-microsoft-com:datatypes">
> <ElementType name="degrees" content="textOnly" dt:type="float"/>
> <ElementType name="weather" content="eltOnly">
> <element type="degrees"/>
> </ElementType>
> </Schema>
>
>
>
>

Teis Draiby

2004-03-30, 10:14 pm

Hi Gohlool,
thank you very much for your answer! It's complaining about your simple hack
so now I'm experimenting with 'the correct way'.
Meanwhile: I'm wondering why I don't need all this if I parse a XSD
document.
What is the difference?

Thank you very much, Teis