PKP 2011 Hackfest

Today there was the kick-off of the hackfest at the PKP 2011 conference. Not many people turned up, but I had the chance to spend some quality (coding) time with PKP developers and to have a sort of personal code sprint  on a side project, that is developing a plugin to integrate a Named Entity Recognition (NER) web service into an OJS installation (see here and there for a more theoretical background).

At the end of the day what I got done was:

• setup a local instance of OJS (version 2.3.6) using MAMB;
• give a quick try to the OJS Voyeur plugin, which unfortunately for me is working only with version <=2.2.x;
• create the bare-bone of the plugin, whose code is up here (for my personal record rather than for other’s use, at least at this early stage);
• write a PHP class to query a web service (that I’m developing) to extract citations of ancient works from (plain) texts;
• come up with two possible scenarios for further implementation of the plugin, to happen possibly earlier than next year’s PKP hackfest 😉

The idea of this post, indeed, is to comment a little on these two possible scenarios.

1. Client-side centric

The first scenario looks rather heavy on the client-side. The plugin is packaged as an OJS plugin and what it does is essentially as follows:

1. after an article is loaded for view, a javascript (grab.js) gets all the <p> elements of the HTML article and send them over ajax to a php page (proxy.php);
2. a php class act as a proxy (or client) for a 3rd party NER web service;
3. the data that are received from via the ajax call are passed on to the web service via XML-RPC;
4. the response is returned by the web service as JSON or XML format…
5. … and then processed again by the JS script, ideally using a compiled template based on jquery’s template capability. Finally, the citations that were extracted are display as a summary box alongside the article.

2. Server-side centric

Instead, in the second scenario that I envisaged most of the processing happens on the server-side.

1. before being displayed, the article is processed to extract <p> elements;
2. the main plugin class (plugin.php) takes care of sending the input to and receiving a response from the NER service;
3. the response is then ran through a template (template.tpl) by exploiting OJS’s templating functionalities;
4. the formatted summary box is injected into the HTML which is now ready to be displayed to the user.

All in all, I think that I came up with (1) mainly because my PHP is rather rusty at the moment ;). Therefore, although I’m quite reluctant to admit so, I might decide to go for (2). However, a good point to opt for the former is the case where the user can decide for each paper whether to enable this feature or not.

Idea for an OJS plugin

I have been meaning for quite a while to find some time to code a plugin for the Open Journal System (OJS) platform. Unfortunately it didn’t happen yet. However, the good news is that the chance somehow came to me, since this year’s PKP conference will be held in few weeks days in Berlin, that is where I recently moved and now live.  And at the same time as the PKP conference there will be a PKP hackfest where I hope to have the chance to push forward my idea for an OJS plugin and eventually get some coding done.

The idea it’s quite simple, but my knowledge of OJS’ is not (yet) such to allow me to have a clear idea of how to implement it. The plugin should enable the detection and markup of certain bits and pieces (read “named entities”) of articles from an OJS installation. Although my application of the plugin is (originally) targeting a specific type of named entities, citations to ancient texts, to be found mainly in Classics journals, it’d possible to generalise the idea for a wider application. Indeed, the plugin could be thought of as applicable to any named entities contained in journal articles, provided that a web service for that is available.

As an example, let’s suppose to have an existing installation of OJS, where an article contains the following paragraph (which is actually taken from a real world article appeared in Greek, Roman, and Byzantine Studies):

Thus, in the paragraphê speeches ([Dem.] 37.58–60, 38.21–22), a binding settlement is sometimes described as a “boundary marker (horos); in an inheritance dispute (40.39), the binding decision is a telos or peras.

The text in bold contains two references to Demosthenes’ works, respectively (1) a reference to lines 58-60 of the speech Against Pantaenetus and (2) another to lines 21-22 of the one  Against Nausimachus and Xenopeithes. The plugin would parse each paragraph and then produce a result somewhat similar to this, where the cited texts are displayed alongside the text article. All in all the whole idea is not much different from OJS’s citation markup assistant, although at the same time it can be generalised to cover other kind of named entities (people, organisations, etc.).

Some aspects that I believe are important for the implementation of such a plugin are:

• client/server architecture: the plugin should act as a client with respect to the Named Entity Recognition web service; I have already a working prototype for a web service (based on XML-RPC) performing the extraction of citations as described above;
• the markup of the extracted named entities should be customisable, ideally based on a template rewrite system, and should allow one to output RDFa or microformatted markup.
• being able to review, correct and therefore store the output of the automatic extraction will be a plus (possibly including interaction with authority lists to which the named entities can be linked to).

So, this is the idea in a nutshell. I’m looking forward to discuss it together with interested OJSers next week in Berlin and I hope there will be a follow-up post with some updates on the hackfest’s outcome.