How to validate a XML Schema

[Siddhartha Singh]

Hi,
If XML can be validated by either DTD or Schema and Schema itself is a XML.
How can we validate a Schema ?
Cheers,
Siddhartha Singh
(e-mail address removed)

 

[Martin Honnen]

Hi,
If XML can be validated by either DTD or Schema and Schema itself is a XML.
How can we validate a Schema ?

There is no complete XML Schema defining the XML schema however the
schema processors usually validate a schema when you load it. For
instance with MSXML 4 you can ask a schema to be validated when you add
it to the schema cache. Consider the following schema with a typo (type
mistyped as typ):

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="GOD" typ="xs:string" />

</xs:schema>

When you load that schema with MSXML e.g. with

var schemaCollection = new ActiveXObject('Msxml2.XMLSchemaCache.4.0');
schemaCollection.validateOnLoad = true;
try {
schemaCollection.add('', 'test20030815Xsd.xml');
}
catch (e) {
alert(e.description);
}

then an exception is caused an the alert shows that the attribute typ is
not supported.

 

[Martin Honnen]

Hi Martin,
Thanks for your reply,
My question was regarding validation and not checking well formedness.
The example you have shown is giving the syntax error and not the
logical error in any schema.

The example schema is well-formed:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="GOD" typ="xs:string" />

</xs:schema>

However it doesn't validate and I have posted how you can check that
with MSXML 4.