Jeni's Musings

This is the talk I prepared for the UKGovWeb Barcamp, in blog form. It’s probably better this way. Most of what’s written here seems blindingly obvious to me, and probably to most readers of this blog, but maybe Google will direct someone here who finds it useful.

Working with public-sector information on the web, one of the things that I take an interest in is making government data freely available for anyone to re-present, mash-up, analyse and generally do whatever they want to do. This post is born out of a feeling that the people who control data don’t realise that the smallest changes can be beneficial: they don’t need to do everything right now, just something.

XTech was subtitled “the mobile web”, but one of the major themes for me was that of the distributed web. The first keynote, by Simon Wardley, gave a vision of a future in which hardware, frameworks and applications are services in the cloud rather than products on machines we own: where we use flickr to store our photographs, Google App Engine to host our applications, and Amazon S3 to store our data. In David Recordon’s keynote (written up by Jeremy Keith), he talked about small, specific services provided by sites that aren’t “destination sites”. The same picture was painted by Gareth Rushgrove in his talk on Design Strategies for a Distributed Web.

A Google Search Appliance (GSA) is a box that you plug into your network which crawls and indexes your data, and serves up the results of searches. Search results come in an XML format, and there’s a built in XSLT engine which means you can convert that XML into as many different views as you like. So you can have HTML-based search results, summaries, feeds, and so on.

My task recently was to debug some XSLT that transformed the GSA XML into an Atom feed. Easy enough, right? The GSA XML format is pretty hideous — most of the elements max out at three capital letters in length (whatever happened to human-readability) — but logical enough, and the mapping is hardly complex.

But all was not as it seemed. The GSA’s XSLT implementation is… how can I put this politely?… “non-standard”. This post describes some of the problems and workarounds.

IE7 gives you a really quite nice view of an Atom feed. Take a look at the one for this blog, for example. You can filter by category, sort by date or title or author, and search for particular words or phrases. Pretty neat.

But it’s only a partial implementation. I’ve been having to create some Atom feeds recently, and getting them to display nicely in IE7 has proven a bit tricky. I couldn’t find any documentation about this with a quick google, so thought I’d blog it for future reference.

OK, so I can’t remain a Luddite for long. What’s a technological solution to the posterity problem, in particular in regard to web applications that tuck away all your data in their databases, just waiting to be forgotten?

Well, what if web applications accepted information as feeds rather than through forms? The original data would be distributed rather than centralised. Web applications would use the web as more than a distribution medium: they would be of the web rather than simply on the web.

A Ruby on Rails specialist friend and I are building a Web 2.0 application. I would say it’s “social networking for the dead” except that I doubt that description would be attractive to most people (my ex-Goth defacto being a rare exception), and it can be for the living too. It’s a bit like all those genalogy websites, except that our focus is on people’s social relationships as well as their familial ones.

(I should say that this is all very casual. We’re both fitting it in around our other responsibilities, and are mainly interested in working together, learning new things, and trying out all the best practices that everyone keeps talking about. So don’t think I’m becoming a dotcom entrepreneur or anything. Its got a very Web 2.0 name, and I’m only not telling you in case you start hitting our servers. We’re nowhere near ready for visitors.)

Another fascinating post from Bill de hÓra, this time on URL design for resources:

Let’s take editing some resource, like a document, and let’s look at browsers and HTML forms in particular, which don’t a do a good job of allowing you to cleanly affect resource state. What you would like to do in this suboptimal environment is provide an “edit-uri” of some kind. There are basically 5 options for this; here they are going from most to least desirable

1. Uniform method. Alter the state by sending a PUT to the document’s URL. The edit-uri is the resource URL. URL format: http://example.org/document/xyz
2. Function passing. Allow the document resource to accept a function as an argument. URL format: http://example.org/document/xyz?f=edit
3. Surrogate. Create another resource that will accept edits on behalf of the document. URL format: http://example.org/document/xyz/edit
4. CGI/RPC explicit: send a POST to an “edit-document” script passing the id of the document as a argument. URL format: http://example.org/edit-document?id=xyz
5. CGI/RPC stateful: send a POST to an “edit-document” script and fetch the id of the document from server state, or a cookie. URL format: http://example.org/edit-document

UPDATE: Dare Obasanjo has written an interesting critique on using the Atom Publishing Protocol as the basis for general purpose sharing of data in the way that the Google Data API does.

Thursday afternoon had a few really interesting talks. I learned about the Google Data API (no longer called gData); Oracle’s use of XLink to represent relationships between documents, and the requirements that entails; using XSLT to create JSON to use Exhibit widgets; and using XMPP to enhance instant messaging.

On Thursday morning, I was down to chair the first session in the “Core Technologies” track. Two interesting papers: one on XForms and one on Google Base. Then I snuck on to the “Applications” track to hear about scientific Wikis and the trials of managing schema repositories.