From the strict rectangles of structured data to the more generous triangles of semistructured data. This lecture gave an overview of what might qualify data as semistructured; trees in general as a mathematical model of data; the particular form of trees in the XPath data model; and their textual respresentation in XML — the Extensible Markup Language.

Finally, some examples of real XML data: from musical scores to financial trading.

Link: Slides for Lecture 9; Video of Lecture 9

Homework

1. Read XML Essentials from the World Wide Web Consortium (W3C).

   Link: XML Essentials — What is XML? What is XML used for?

2. Read the sections from Chapter 2 of Møller and Schwartzbach on the photocopied handout that was distributed in the lecture. You can also get a copy from the ITO office on Level 4 of the Appleton Tower.

3. Find an SVG file and open it in a text editor to study its XML content.

4. Find a Microsoft Office .docx file and look at the XML content in that. This format (OOXML) is in fact a zipped archive of XML files, so you will need to unzip it first. Depending on your platform, this may require renaming the .docx extension as .zip

   Link: Wikipedia on Microsoft’s OOXML format

References

To learn more about XML, try any of the following.

• Read more of An Introduction to XML and Web Technologies, the book in today’s lecture handout. There are copies available in the Main Library HUB.

• Browse the full XML specification.

• Work through the MusicXML tutorial.

• Have at look at some documents in the Financial Products Markup Language: such as a composite basket equity swap or a European swaption straddle. The full site has dozens of such examples.