Check the Integrity of a W3C Schema
Use the
xni.XMLGrammarBuilder class from Xerces to do some
extra checking on your schemas.
Whether you create a W3C XSD Schema
with the same tools you use to create other XML documents or use a
specialized schema-generation tool to create one, parsing it against
the schema in the Schema for Schemas appendix of the W3C Schema
recommendation (http://www.w3.org/TR/xmlschema-1/#normative-schemaSchema)
may alert you to some problems, such as whether you mistyped the name
of a schema definition element or put one schema definition element
inside of another where it doesn’t belong. There are
other potential errors that this won’t catch,
though; for example, what if your maxOccurs value
for one element is less than the minOccurs value
for the same element?
The xni.XMLGrammarBuilder class manages this
multidocument validation by creating a compiled version of that
schema in memory and then re-using that compiled version for each
instance document passed to it. Like any compiler, it makes various
integrity checks as it compiles. If you’re
developing an XSD schema, this round of checks can help you before
you’ve created your first document that conforms to
that schema.
Imagine that you just drafted a schema, badschema.xsd, which has the following problems:
In the content model for the
orderelement, theitemNumelement has amaxOccursvalue of1and aminOccursvalue of4. If the value must be greater than or equal to 4 or and less than or equal to 1, that ...
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