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Maintained by: David J. Birnbaum (djbpitt@gmail.com) [Creative Commons BY-NC-SA 3.0 Unported License] Last modified: 2023-01-08T17:47:32+0000

XPath assignment #3

You can find an XML (TEI) version of Shakespeare’s Hamlet at http://dh.obdurodon.org/bad-hamlet.xml. We’ve deliberately damaged some of the markup in this edition to introduce some inconsistencies, but the file is well-formed XML, which means that you can use XPath to explore it. You should download this file to your computer (typically that means right-clicking on the link and selecting save as) and open it in <oXygen/>.

Prepare your answers to the following questions in a markdown file upload it to Canvas as an attachment. As always, code snippets (including XPath snippets) in markdown must be surrounded with backticks.

Some of these tasks are thought-provoking, and even difficult. If you get stuck, do the best you can, and if you can’t get a working answer, give the answers you tried and explain where they failed to get the results you wanted. As always, you are encouraged to ask questions in the #xpath channel in Slack, but because you want to make progress in learning to debug your own code, your questions should tell us what you tried, what you expected, exactly what you got instead (not just didn’t work or got an error), and what you think the source of the problem is. Sometimes writing that sort of request for advice that will help you figure out what’s wrong on your own (see Rubber duck debugging), and even when it doesn’t, it will help us identify the difficult moments.

These tasks require the use of path expressions, predicates, and functions. References to Kay are to the Michael Kay book; there’s a link in our online course description to a PDF version accessible through the Pitt library system. There may be more than one possible answer.

Using the Bad Hamlet document and the XPath browser window in <oXygen/>, construct XPath expressions that will do the following. Give the full XPath expressions in your answers, and not just the results:

  1. What XPath expressions will select the last stage direction <stage> in the entire document? (Note: there should be only one!)
  2. What XPath expression will find the last member in the cast list at the beginning of the document and select the @xml:id attribute that is associated with it?
  3. What XPath expression will select all <sp> elements with more than 8 line (<l>) subelements (which may be children or deeper descendants)? You’ll need to use the count() function (Kay 733–34).
  4. Building on your answer to the preceding question, what XPath expression will tell you how many line subelements each of those speeches actually has?
  5. Building on your answers to the preceding two questions, what XPath expression will find the speakers of all speeches that have more than 8 line subelements? Once you’ve found the speeches that have more than 8 lines, you can find the speakers of those speeches by just adding another path step, but you’ll get some duplication, since a single person may have more than one long speech. Your answer to this question should get rid of the duplicates, and return just a list of names of speakers without duplication. You’ll need to use the distinct-values() function (Kay 749–50).

Optional bonus questions

  1. Question #1, above, asked how you to provide an XPath path expression that would select the last stage direction (<stage>) in the play. What XPath would find the last line (<l>) in the play? What XPath would find the last stage direction or line (that is, whichever of the last stage direction and last line comes last)? You’ll need to use the union operator (Kay 628–31).
  2. Question #2, above, asked you to provide an XPath path expression that would select the @xml:id associated with the last cast member in the cast list. What’s the difference between an XPath that returns the @xml:id attribute itself and an XPath that returns just the value of the @xml:id attribute? That is, what are the two XPath expressions and what does each of them return? You’ll need to use the data() or string() function (Kay 741–43, 877–79).
  3. Question #3, above, asked you to provide an XPath path expression that would select all of the speeches (<sp> elements) with more than 8 line (<l>) subelements. What XPath expressions would select speeches with more than 8 line child elements (one XPath expression) and speeches with more than 8 descendant line elements (the expression you created for #3, above)? How do those results differ? If there are descendant line elements that are not children of a speech, what XPath expression will return the element names of their parents? You’ll need to use the name() function (Kay 835–37).

What to submit

You should turn in your answers to the above questions in a markdown file, that is, a file with the extension .md.