Top Ten XML Myths
XML is a scary thing. We all know it’s around us””in our websites, in our software, probably in our cereal and in our city water too. Perhaps it’s the ubiquity of XML combined with its unknown qualities that makes it seem a tough technology to master, but my recent XML Workflow tutorial with Jim Maivald and Cooking With XML really helped me understand XML, what it does and doesn’t do, and its uses for today’s designer. If you’re a designer for print or the web, read the following ten XML myths and re-learn what you have learned.
10. XML is a special language requiring special editors. Some people may think XML requires expensive software or even web design software like Dreamweaver to create. Guess what? It’s totally composed of plain text and TextEdit or Notepad will write XML just as easily as XMLSpy, a leading XML editor.
9. XML is only for the web. I took this tutorial at the InDesign Conference, so that’s your first clue that XML does more than just websites. XML is data, so you can think of it as a tab- or comma-delimited file, able to be imported into any application that can understand it and display it.
8. XML does things to data. As mentioned above, XML is data and that’s all it is. Without software like InDesign to parse the data or something like an XSLT file to interpret it and style it, XML is just a bunch of text.
Note: XSLT allows XML to be transformed and displayed by style sheets, thus creaitng a method for displaying XML data as styled text and visual elements. It’s one of the most popular ways to publish XML on websites.
7. It’s too easy to get bad XML data published. The beauty of XML is that a parser or interpreter (like XSLT) requires valid XML to process it properly. There are a lot of rules with XML that must be obeyed, but in the end it’s a boon for XML authors because that means either the XML is valid, and everything shows up correctly, or the XML is invalid and the application will let you know. Print designers: think of XML as data’s PDF/X-1a. Creating a PDF/X-1a out of a document with RGB images doesn’t generate a PDF, but an error. The process makes sure you fix everything before you can move on. XML validates in exactly the same way.
6. XML is hard to write. There are some difficult things to remember as far as syntax goes, especially for XSLT, but XML itself is actually straightforward. The logic of XML is so simple that practically anyone can write it, and as with HTML there are several options for writing XML without having to type a line of code. Exporting databases as XML is a great way to do just that.
5. XML is a new kind of language. XML and HTML are actually based on the same language, SGML from the 1970s. Look at the structure of XML and HTML code side by side, and you’ll see they are closely related. If you can write HTML, you are actually more than qualified to write XML after learning a few things about syntax and rules.
4. XML hasn’t penetrated the mainstream design application market yet. Wrong! Not only is XML being used by some of the biggest design applications out there, some (like Dreamweaver 8) are made of the stuff! At the conference I got to know the Tags palette in InDesign, which is not used to create HTML but to work with imported XML in order to publish an infinite number of data-driven documents in only a few steps. Many other applications out there can leverage XML in the same way.
Not only are design applications working with XML, most major web browsers including Internet Explorer are XML-compatible.
3. Displaying XML data is tough. With technology like Cascading Style Sheets and the parsing abilities of applications like InDesign, bringing XML from pure data to styled data is easier and easier. It’s still the last and hardest step before having a finished data-driven document or product, but once you get the hang of it it’s actually pretty easy.
2. XML has too many rules. If you write HTML, you know that every tag does something different. is required,is required around the body code, and so on. With XML, other than a few things such as the required DOCTYPE, tags are whatever you want them to be. Make up your own! As long as the XML parser or interpreter knows what to do with them (and you are in control of this as well) you can practically make up the rules.
1. You can get by without knowing anything about XML. Depending on your situation, this might be true. However, you are probably already using XML””metadata, InDesign Snippets, preference editing and webpages are all places where XML is in use today. At least a fundamental grasp of XML will be necessary in a few years’ time. You may not make your living off it, but you will be coming across it more and more.