Now that you know how to use an XML Schema definition, we'll turn to the kinds of errors you can see when the application is validating its incoming data.To do that, you'll use a document type definition (DTD) as you experiment with validation.Many parser implementations have added proprietary extensions or methods at the cost of code portability.While these software packages may implement the SAX interface, the methods for setting document and schema validation, namespace support, and other core features are not standard across parser implementations.By now, you have done a lot of experimenting with the nonvalidating parser.It's time to have a look at the validating parser to find out what happens when you use it to parse the sample presentation.From there, I’ll move on to some more handlers: the left over from the last chapter.At that point, you should have a comprehensive understanding of the standard SAX 2.0 distribution.
Because JAXP-compliant parsers are not namespace-aware by default, it is necessary to set the property for schema validation to work.
However, there are several more topics that will round out your knowledge of SAX.
While I’ve called this chapter “Advanced SAX,” don’t be intimidated.
If the parser is not 1.2-compliant and therefore does not support XML Schema, it can throw a Note: You'll learn about namespaces in Validating with XML Schema.
For now, think of these attributes as the "magic incantation" you use to validate a simple XML file that doesn't use them.