Factor out common code for models which deal with geographic points

into a base class.

app/models/geo_record.rb

@@ -0,0 +1,29 @@
+class GeoRecord < ActiveRecord::Base
+  before_save :update_tile
+
+  def self.find_by_area(minlat, minlon, maxlat, maxlon, options)
+    self.with_scope(:find => {:conditions => OSM.sql_for_area(minlat, minlon, maxlat, maxlon)}) do
+      return self.find(:all, options)
+    end
+  end
+
+  def update_tile
+    self.tile = QuadTile.tile_for_point(lat, lon)
+  end
+
+  def lat=(l)
+    self.latitude = (l * 10000000).round
+  end
+
+  def lon=(l)
+    self.longitude = (l * 10000000).round
+  end
+
+  def lat
+    return self.latitude.to_f / 10000000
+  end
+
+  def lon
+    return self.longitude.to_f / 10000000
+  end
+end