Originally posted by Julien Martin: How does the parser/validator match the namespace (http://www.w3.org/2001/XMLSchema) to the schema of schemas? Is the schema of schemas held locally or is it fetched from the www?
As a rule (default), validation is an optional activity. The namespace declaration just provides an identifier (i.e. name) for that namespace � so it exists primarily to avoid naming collisions - nothing else. You usually have to configure the parser to do the validation. During validation the XML document is validated against the document's schema but the document's schema isn't validated. You can validate a schema against XMLSchema � in that case the schema is "the XML Document" being validated. However you will have to provide the parser with a location of the version of XMLSchema you wish validate against � that version can be local or over the network. An XML document can always provide the location of the schema that it is to be validated against � that's what "schemaLocation" is for. However that is only a suggestion. You can configure the parser to use a different copy (like one that is locally cached) and that one will be used instead of the one specified with "schemaLocation".
Hello Peer, Thanks a lot for your answer. It is interesting what you say about the configuration of the parser. In my case, I use Netbeans in order to validate xml SCHEMAS and was just wondering where NB fetches the schema of schemas (or indeed whether it does this at all) in order to validate my schemas. Julien.