XML: What, Why, When & How?

Notes from the Workshop
June 2003

The PowerPoint Slides:

• XML Day 1: Introduction, bits and pieces, XHTML
• XML Day 2: DTDs, Stylesheets, and assorted "Xs"

For this class we used the Oxygen XML editor available at: http://www.oxygenxml.com
Other XML software is available at: http://www.xmlsoftware.com

Some sample files we used:

To use these, download them to a folder on your computer. Open them with Oxygen. If you just want to see their contents without actually downloading them, you can click on them and then choose Edit: Page View or Edit: Source View in your web browser.

• hale.html - this is an html file that can be read by a web browser. Try opening this file in an XML editor and check it for well-formedness. You will find it is not well-formed. Now try to validate it against one of the following XHTML DTDs. It's even worse.
• To see the contents of the files, click on the link. If your browser does not display the contents (for example, Internet Explorer may display an error message), choose Edit: Page View (Netscape) or View: Source (Internet Explorer). To save the files, choose File: Save As.
• xhtml1-transitional.dtd - a fairly forgiving xhtml dtd.
• xhtml1-strict.dtd - use this one if you want the cleanest xhtml.
• xhtml1-frameset.dtd - the dtd you will need if you are creating xhtml documents with frames
• xhtml-lat1.ent, xhtml-special.ent, xhtml-symbol.ent - these are entity files, files that contain special characters that you might want to insert into your xml documents including things like €, Δ, ∑, etc.

In the class we explored three types of documents: a party invitation, a recipe, and a play (see PP slideshow for examples). We analyzed their structures in terms of creating a DTD. Here is a sample DTD drawn from the party invitation example:

• party.xml - the invitation. To see the raw contents, click on it and then choose Edit: Page View or View: Source.
• party.dtd - the DTD generated by Oxygen from the party.xml file. Note how it contains both elements and attributes.
• party.xsl - a simple XSLT stylesheet for transforming the party.xml file into a HTML file for display on the web.

The Text Encoding Initiative's DTD is used for creating humanities related documents such as transcriptions of manuscripts, dictionaries, literature, etc. It is a flexible, powerful, and quite large DTD. You can learn more about it at http://www.tei-c.org. At that site you can create your own TEI DTD, or, if you would like to see a sample, see

• tei-pizza.dtd - a full TEI DTD created from the TEI Pizza Baker!
• testtei.xml - a very simple file based on the TEI. To see the raw contents, choose Edit: Page View or View: Source.
• testtei.dtd - this is a DTD generated by Oxygen from the simple testtei.xml file. That is, Oxygen read the elements in that file and created a new DTD based on them. As I only used a few of the hundreds of possible TEI elements, this is a very small DTD!
• testtei.xsl - an XSLT stylesheet for the testtei.xml file. This stylesheet transforms the XML file to an HTML file so it can be displayed on the web.

Questions? Comments? Hope Greenberg. Created/updated: June 2003.