Ivan’s private site

January 14, 2009

A different usage of RDFa…

Talis and the University of Plymouth have just published a new SW Case Study at W3C. It is really a nice system which helps university students and instructors alike. There is no need for me to go into the details of the case study (I would probably not do justice anyway), it is much better if you read it right at the source

However, there is a small detail (compared to the rest of the study) that caught my attention because it describes a possible usage of RDFa that, I must admit, I did not consider before. Indeed, here is what the text says:

The interface to build or edit lists uses a WYSIWYG metaphor implemented in Javascript operating over RDFa markup, allowing the user to drag and drop resources and edit data quickly, without the need to round trip back to the server on completion of each operation. The user’s actions of moving, adding, grouping or editing resources directly manipulate the RDFa model within the page. When the user has finished editing, they hit a save button which serialises the RDFa model in the page into an RDF/XML model which is submitted back to the server. The server then performs a delta on the incoming model with that in the persistent store. Any changes identified are applied to the store, and the next view of the list will reflect the user’s updates.



  1. That’s a nice one. Do you know of any such online demo?

    I am having hard time believing it works and would like to try out if I am imagining it correctly. Browsers have so much tendency to create spaghetti markup every time you use their WYSIWYG capabilities.

    btw: In semantic tagging group we have just found another big barrier for RDFa adoption: browsers don’t support finding it in efficient way. Producers of browser extensions that provide additional services on top of web pages said it’s a non starter until there’s a fast function to actually find out if RDFa is present and where it is.

    Andraz Tori, Zemanta

    Comment by Andraz Tori — January 14, 2009 @ 14:54

  2. Andraz, I am just a go-between here, having edited the case study for publication. I do not have a link to an online demo, I guess you should ask the Talis guys for this…

    As for the second item: I understand:-( Having said that, afaik the Yahoo! searchmonkey toolkit does find RDFa content, ie, it is not impossible. Also, again unless I am mistaken, Ben Adida has some javascript routines to find RDFa content…



    Comment by Ivan Herman — January 14, 2009 @ 15:01

  3. Yeah, there is javascript to read it. The issue for browser extensions is that they need to parse every page you go to, and even smallest performance penalty means unsatisfied users. That’s why I hope you are working with Mozilla and others to add native get_rdfa_subtree() or something similar.

    I hope it is fixed in the same way as native implementation of getElementsByClassName() in browsers fixed many performance issues regarding dynamic web pages.


    Comment by Andraz Tori — January 15, 2009 @ 21:17

  4. […] – “A Linked Open Data Resource List Management Tool for Undergraduate Students“, and discussion on it has already started over on Ivan Herman’s […]

    Pingback by W3C Case Study: A Linked Open Data Resource List Management Tool for Undergraduate Students :: Work In Progress — January 15, 2009 @ 22:14

  5. A few more notes on the WYSIWYG editing and RDFa processing can be found here on a blog post I’ve just knocked up.


    Comment by Andrew Bate — January 15, 2009 @ 22:20

  6. Not a complete answer, I know. However it’s worth bearing in mind the huge performance improvements we’ve seen in all Javascript engines in the last year. And there’s probably more to come.

    eg. http://weblogs.mozillazine.org/roadmap/archives/2008/08/tracemonkey_javascript_lightsp.html

    Comment by Dan Brickley — January 16, 2009 @ 10:27

  7. […] Manager, and Fiona Grieg, one of our pilot customers, describe the work in a W3C case study. Ivan Hermann then picks up on one of the way we decided to implement editing using RDFa within the H…. In the case study Chris describes it like this: The interface to build or edit lists uses a […]

    Pingback by Resource Lists, Semantic Web, RDFa and Editing Stuff | I Really Don’t Know — January 16, 2009 @ 10:39

RSS feed for comments on this post.

Blog at WordPress.com.

%d bloggers like this: