Using XML with Legacy Business Applications

Output Validation in CSVToXMLBasic.cpp

There were a few idiosyncrasies with validating XML as input, but validating output can be downright tricky. I expected output validation to be a piece of cake, but it took me a couple of hours to figure out what was going on and to make it work correctly. Going through the exercise may help you understand a bit more about how MSXML does things.

The first time I coded the routine I just added a block of code to CSVToXMLBasic.cpp that was almost identical to the input validation snippet shown above in XMLToCSVBasic.cpp. It didn't work. I got a validation failure message indicating that “the root element had no associated DTD/schema.”

MSXML stores schemas internally and makes them available through the IXMLDOMSchemaCollection/XMLSchemaCache ...