Learning XML, what are the next steps? (navigating a document elegantly)

Question

The xml fields seems filled wit jargon, (well to new XML users its jargon), DTD, DOM, and SGML just to name a few.

I've read up on what an XML document is, and what makes a document valid. What I need are the next steps, or how to actually use an XML document. For the .Net platform there seems to be a plethora of ways to traverse an XML document, xpath, XMLReader (from System.Xml), datasets, and even the lowly streamreader.

What is the best approach? Where can I find more "advanced beginner" material? Most of the material I find is about differences in XML parsing approaches (like performance, more advanced stuff that assumes one has XML experience), or explaining XML in general terms for non-programmers (how it's platform independent, human readable, etc.)

Thanks!

Also for specifics I'm using C# (so .Net). I've tinkered around with XML in vba, but Ive run into the same problems. Practical application here is getting an iOS application to dump info into a SQL server.

Answer 1

Download Linqpad and it's samples. It has quite a large library of examples of Linq to XML that you might find very usefull.

http://www.linqpad.net/

Answer 2

It's hard to do this without some idea of the problem you want to solve.

You need to make a decision whether you want to process the XML using procedural languages like C#, or declarative languages like XSLT and XQuery. For many tasks, the declarative languages will make your life much easier, but there is more of a learning curve, and a lot depends on where you are coming from in terms of previous experience. Generally working at the C# level is appropriate if your application is 10% XML processing and 90% other things, while XSLT/XQuery are more appropriate if it's 90% XML manipulation and 10% other things.

Answer 3

Learn the two primary (early) methods of processing an XML document: SAX and DOM. Then learn how to use one of the new "pull" parsers.

Without learning how to parse XML, you are in danger of designing XML that poorly supports the task(s) at hand.

Recommended reading, even if you are working in C#

Java & XML, 2nd Edition (OReilly)
Java & XML data binding (OReilly)

SAX and DOM are universal enough that the language differences between C# and Java are not the hardest part of using XML effectively. Perhaps there are C# equivalents of the above, if so then use them.

As far as the "best" means of using XML is concerned, it depends heavily on the task at hand. There's no "best" way of using a text document, either! If you are processing very large streams, SAX works great until you need to cross reference. DOM is great for "whole document in memory" processing, but due to it's nature suffers when the documents get "too big".

The "right" solution is to tailor your XML to exploit the strengths of the means by which it will be processed and transformed into useful work, while avoiding the pitfalls that accompany the chosen processing methodology. That's pretty vague, but there's more than one way to skin this proverbial cat.