Graticule and acts_as_geocodable, which I wrote about here, has a new release with a couple of updates worthy of note. First up is the addition of new geocoders which provide better coverage of locations outside North America, and second is IP address to co-ordinates conversion similar to that in GeoKit. Brandon has the lowdown, and I’ve updated the Comparison chart on the wiki.
Along with Bill Eisenhauer, I’ve been digging into what it would take to fix the problem I found with GeoKit, that it wouldn’t support :include queries properly. The explanation has seen us going deep into the internals of ActiveRecord to discover, as others have before, that the :select parameter (which GeoKit uses to build its distance column in the query) and the :include parameter don’t play nicely together. The reason for that is that Rails employs special methods to build the select parameters when there’s a :include in the query (ie. when you’re joining with other tables and eager-loading them) and currently ignores :select along the way. GeoKit would ordinarily produce SQL along the lines of: ...
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. ...
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. ...