This post originated from an RSS feed registered with Ruby Buzz by Agnieszka Figiel. Original Post: Announcing acts_as_locatable [defunct] Feed Title: agnessa's blog Feed URL: http://blog.agnessa.eu/xml/rss/feed.xml Feed Description: ruby and rails impressions from a beginner developer Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Agnieszka Figiel Latest Posts From agnessa's blog

acts_as_locatable used to be a very simple rails plugin that facilitated basic operations on geographical data. It is no longer supported (read on for an explanation).

• Ruby GeoKit—Rails plugin for building location-based apps. It provides geocoding, location finders, and distance calculation.
• GeoRuby—a library to be used with a spatial data enabled database backend (PostGIS, MySQL geo columns)

So what happened to acts_as_locatable?

I noticed many people still reach my blog by searching for the acts_as_locatable plugin. If you’re one of them and you’re currently blasting curses at its being removed, here goes an explanation.

I wrote acts_as_locatable by assembling code, algorithms and information from the following sources:

• ruby library location.rb, which has functions for calculating distance between objects and finding objects in range. My plugin owed a lot to this code. I basically copied the Cosine Law calculations from there and used the ‘objects in range’ idea.
• javascript functions from MovableType—I implemented (=rewrote in ruby) these more precise algorithms as alternatives to the Cosine Law:
  • Haversine Formula
  • Vincenty Formula
• the Rails plugins tutorial from Nuby on Rails: part 1 and part 2

As you can see, all that’s needed to write this plugin had been available on the web for a while, long before it came to my mind to put it together into a useful tool. Nevertheless, I was accused of stealing code—but not by the author of any of the above mentioned resources, but by someone who happened to be building a location aware application and was quite sure the code came from there.

Once I managed to clarify this wasn’t true, I was accused of stealing the idea. Obviously, one must be lucky to consider themselves an author of concepts already familiar to ancient Babylonians, that had been applied in computer science since the 1980’s (“the first location-based applications reported in the computer science literature”). Needless to say, these ideas found their way into the World Wide Web very early, and they’ve already been for some time in the Mobile Social Software domain.

Unfortunately, my refusal to take aal down could have caused trouble to people I respect, so I gave it up, sorry for this. I hope the above mentioned resources will be of use.