A huge class of applications are nothing more than a bunch of relational database tables with a simple Create Read Update Delete (CRUD) user interface. More and more these applications are being built as web-apps, eg. the user interface is HTML/CSS/Javascript running inside a users’ browser, and the backend is a simple server-side layer (Perl/PHP/Ruby/J2EE/..) controlling access to an online database. This architecture is becoming increasingly easy to implement with the advent of server-side web/application frameworks (Catalyst/Rails/Spring) and database Object Relational Mappers (DBIx::Class/ActiveRecord/Hibernate,..) that remove most of the tedium, along with awesome Javascript libraries in the front-end (ExtJS/jQuery/Dojo/..) that let you make the user interface much more engaging and adaptable.

What happens, however, when your intended users have no internet access? I was recently faced with that exact problem: My Dad (Dr Ted Donelan) runs a pro bono dog health program in Maningrida, a self-governing aboriginal community in Arnhem Land (500km east of Darwin) where, unless you want to pay through the teeth for that Telstra NextG internet rubbish, there’s no easy access to the internet. And certainly no way of logging into a website while you’re riding around from house to house in a ute or carrying out surgery on an outdoor trestle table underneath the local grog-shelter. Dr Ted wanted a way to record the statistical information that he collects (dog body conditions, mange scores, fleas, ticks, etc..) along with his formal veterinary records of surgical cases, medical cases, etc.. All of which can be neatly captured in a handful of relational tables (attested by the fact that previously he had been recording his data in hand-written tables, later to be transferred to Excel). I suppose I could have stepped back into the C#/Java world and implemented a stand-alone app to solve the problem, but I’m not familiar enough with any frameworks in those languages to whip up something quickly. And that was the point, I only had a small amount of time to come up with a solution. And what I really wanted was a way to build him a stand-alone app using my existing HTML/Javascript/CSS-fu..

Cue Adobe AIR.. a desktop framework that lets you build traditional dektop apps using web technologies. Now I’m not the biggest fan of proprietary technology (Adobe Flash being a prime example) since it goes against the grain of the Open Web, but there’s really no open-source alternatives at the moment.

The first really awesome AIR app I saw was ExtJS creator Jack Slockum’s “Simple Tasks“. Check out the screen-shots and you’ll see why I was excited: here was a desktop application with an embedded (SQLite) database running pure HTML/CSS/Javascript. And not just any Javascript either. ExtJS shines most when used to create windows application-style interfaces, and as such it’s the perfect library to use in an AIR app when you really are building a desktop application.

Simple Tasks is released under GPL v3, so I decided to base my code on Jack’s. It was the right decision. With no prior experience with AIR it took less than a day to have a working prototype, and by working I mean a full database implementation, an editable data grid and an Add/Edit form for individual rows, all with the trademark ExtJS polish. That’s ridiculously fast.

After about 4 days with lots of feedback from Dr. Ted we had a finished app, named Tarpo, complete with polished input forms, reporting, backup, CSV/XML export, …

I’ll be releasing Tarpo under GPL v3. Until then I’ve got a little page where you can install it straight off the web and have a play. Dr. Ted is heading up to Maningrida next week so I’m excited to see how Tarpo goes on her first test-run. If everything works well we’ll make her available to other Vets running similar programs in other indigenous communities. One cool follow-on from this will be that vets running AMRRIC-endorsed programs could use Tarpo to submit their activity reports direct to the AMRRIC website (which I recently developed).

Andy (also of SDH) is whipping up a Tarpo logo for me, which I’ll post up here as soon as he’s finished inking it!