Why would an application or web service be designed to trust external
input? Perhaps there are circumstances where external input can be
trusted, but surely they are extremely rare?
>> if you don't trust anything, why
>> are you processing the XML at all?
> I don't understand your question Michael. Why is the format of external input relevant to the trust issue?
What is the external input? Let's say it's a weather forecast. How do
you know it's a reliable weather forecast, not a pure invention copied
from some horoscope? You know who sent it, and you trust them. If you
didn't trust them to supply useful information, you wouldn't use it. If
you can trust it to contain reliable information, why do you distrust
its format? Perhaps your experience tells you that the content is
trustable but the format isn't. In that case, you are doing the right
thing. But if you didn't trust it at all, you wouldn't touch it with a
bargepole.
Michael Kay
Saxonica
