I took an XML training class a couple weeks ago. However I have not been able to do any real XML work due to other constraints at work. Therefore I decided to do an XML refresher to make sure I did not forget the things I learned in class. I signed up for an online course from About dot com. They provided some courses that are controlled through e-mail. I chose the course “XML 101” by Jennifer Kyrnin.Perhaps this online course is not as current as the recent one my company paid for. This course stated that XML is not a programming language. It is also not a language of tags. Instead, XML is instructions on how to create the tags. It is a markup language to define information. XML is a meta language.
The online course covered Document Type Definitions (DTDs), which are the grammar of the XML document. The second line of an XML file should be the DTD. However you can omit the DTD line.
The latest specifications for XML are at the W3C web site. There is a lot of jargon associated with XML. However XML is not hard to learn. An entity is a storage unit for XML. Processing instructions were covered. Elements in XML are case sensitive.
Kyrnin recommended that you learn HTML before trying to learn XML. She says the benefit of XML is that you can move processing from the server to the client. So far I have only read through the first lesson. There are a lot of ads in the course material I receive. However the course is free so it is a reasonable trade off. Given the coverage of DTDs already, I wonder if this course is going to cover XML Schema as well.
