In the above analysis, we assumed that the instructor created no data structure of his own.
He does not need to create any data structure of his own.
What he needs to do is to first modify the DOM tree (i.e., set value to the 'grade' node) and then save the whole modified tree.
Writing a test is also the best way for you yourself to figure out if you really understand the issue you think you have with sax-js.
Validates the XML string/file against the specified XSD string/file.
If he choose to use a SAX parser instead of a DOM parser, then in this case he has to create a data structure which is almost as complicated as a DOM tree before he could get the job done. But I am sure that both Xereces J's SAXParser and DOMParser fully support namespace.
The following callback methods are provided in both of them (note, although callback methods are typically used in SAX parser as I mentioned before, Xerece J's DOMParser actually also provides most of these callback methods) Yes, of course, because the use of a DOM parser and a SAX parser is independent.
For example, a DOMParser is rich in functionality (because it creates a DOM tree in memory and allows you to access any part of the document repeatedly and allows you to modify the DOM tree), but it is space inefficient when the document is huge, and it takes a little bit long to learn how to work with it.
A SAXParser, however, is much more space efficient in case of big input document (because it creates no internal structure).
What's more, it runs faster and is easier to learn than DOMParser because its API is really simple.