Two things must be understood about the validating parser: method on white space that it knows to be irrelevant.
From the standpoint of an application that is interested in processing only the XML data, that is a good thing because the application is never bothered with white space that exists purely to make the XML file readable.
The relative "uri="s are resolved relative to the location of the catalog document.
This example xconf file turns the implicit validation off.
In other words, it can tell you whether the document is valid.
If validation is not activated, however, it can only tell whether or not the document is well-formed, as was shown in the previous section when you deleted the closing tag from an XML element.
uses the non-validating parser by default, but it can also activate validation.
In fact, it took Larry Wall more than a couple of months just to add the Unicode support to Perl that XML assumed.
For validation to be possible, the XML document needs to be associated to a DTD or an XML schema. Up until this point, this lesson has concentrated on the non-validating parser.
This section examines the validating parser to find out what happens when you use it to parse the sample program.
The Py XML package is a collection of libraries to process XML with Python.
It contains, among other things * xmlproc: a validating XML parser. * sgmlop: a C helper module that can speed-up and by a factor of 5.
The exact interpretation of this requirement varied from person to person.