Geography

There’s quite a bit of overlap between GeoKit and acts_as_geocodable/graticule, as the latter pair were based on GeoKit. But it provides at least one feature (IP-based location lookup) that they don’t, so I decided to give it a whirl. Since my main geographically related projects are both now based on plugins that I’m pretty happy with and which suit them well, I decided to resuscitate an old sample piece. A few months back I wrote about scraping the Grand Rapids bus routes site and put up a toy application utilising the resource features in then-edge Rails. I’ve been meaning to return to that project to test out some features in ActiveResource, but in the meantime it seemed like it might be useful to be able to search for the nearest bus stop. ...

After writing my review of acts_as_geocodable/graticule earlier in the week, I decided to go searching for geocoding services that might offer data for addresses outside of North America. One that I came across is at Local Search Maps. There’s an introductory blog entry here. The API is a little different in that it returns its data as javascript strings, but otherwise it’s simple enough to send a GET for a given address and get back the data. To see how easy it is, I decided to code up an extra geocoder for graticule that would use this service. ...

acts_as_geocodable ( blog entry, repository) is the newest kid on the rails geo plugin block. It actually consists of two parts, a gem called graticule which handles the actual geocoding, interacting with external services, etc, and the plugin which offers extensions to your models. I like that separation. Having the generalised code in a gem and the rails-specific hooks in a plugin makes a lot of sense and makes it much easier to use the core code in non-rails ruby apps, and having a single gem that supports multiple services allows for built-in failover should the preferred geocoder be unavailable. ...

There seems to be quite a plethora of Ruby/Rails libraries appearing aiming to simplify handling geography and distances. In some cases these libraries do quite distinct things (zip codes vs. longitude/latitude, map output vs. distance calculations) but they’re frequently lumped together and it’s difficult to tell which will be best to use in your projects. I’ve used several of these projects and have previously blogged about YM4R and acts_as_locateable, but I’m still not sure which I’d pick for new projects. So I thought it would be helpful to try to put together a comparison of which libraries offer what functionality. Here I’ll just offer a quick chart, but I’m hoping to write them up in a bit more detail over the coming days/weeks. If there’s sufficient interest, I’d consider moving this out to a wiki for more general use. ...