Reading through my yesterday’s blog entry on XLink, I feel there are things I need to clarify. In no particular order, here goes…
- I think that a schema of some kind (speaking in the general sense and thus including anything from DTDs to XSDs) is always necessary for XML to work well. I know, that sets me apart from quite a few of the young whippersnappers in XML today, but I never consider the well-formedness advantage an advantage when it was marketed as such. But then, I’m a dochead, to borrow Ken Holman’s terminology.
- Namespaces frequently make life difficult, especially for those of us who feel that DTDs are superior to XSDs. Those pesky namespace attributes often keep popping up when processing XML, resulting in bug reports from desperate technical writers. And they all know my mobile number, it seems. However, namespaces really are a must in these days, regardless of your refusal to import foreign namespaces to your XML, because most of XML’s really useful sister recommendations depend on them.
- I do consider data typing in XML to be largely unnecessary, if we stick to using XML for documentation and publishing. Only rarely have I felt the need to include data typing in a schema, and in most of those instances I have been proven wrong by more sensible colleagues (or come to my senses on my own, resulting in the quick removal of unnecessary data types in my XSD).
- It is a pain to implement XLink in an XSD, but largely because of reasons that have nothing to do with XLink as such and everything to do with problems with namespaces (such as the problem hinted at above). Plus, of course, the fact that different XML editors still seem to implement different parts of the XML Schema recommendation in differing ways (or not at all).
- DTDs, on the other hand, work like a charm with XLink attributes added, provided that your tools follow the XML spec. I have experienced problems with MSXML and its derivatives, which proves my point.
Thank you for reading.