Geocoding addresses with geocoder gem and PostGIS database with RGeo

activerecord, callback, geocoding, postgis, ruby-on-rails

Solution

It was a bloody typo...

It works. I leave it up, maybe someone else has the same issue or a better solution...

I have also added the `reverse_geocode` case.

Now look what it can do:

1.9.3p194 :310 > loc = Location.new(name: "Vatikan")
 => #<Location id: nil, name: "Vatikan", latlon: #<RGeo::Geographic::SphericalPointImpl:0x8148add8 "POINT (0.0 0.0)">, created_at: nil, updated_at: nil, address: nil> 
1.9.3p194 :311 > loc.save
   (0.2ms)  BEGIN
  SQL (0.6ms)  INSERT INTO "locations" ("address", "created_at", "latlon", "name", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["address", "Via Pio X, 00120, Vatican City"], ["created_at", Sat, 17 Nov 2012 19:26:59 UTC +00:00], ["latlon", #<RGeo::Geographic::SphericalPointImpl:0x81570554 "POINT (12.453389 41.902916)">], ["name", "Vatikan"], ["updated_at", Sat, 17 Nov 2012 19:26:59 UTC +00:00]]
   (0.9ms)  COMMIT
 => true

I love this! :-)

Problem

I am trying to use the geocoder gem for looking up addresses and coordinates. I want it to work together with my PostGIS spatial database and the RGeo gem, which uses POINT features instead of saving latitude and longitude values separately. So I have tried to work into my model to save the results from the geocoder lookup into an RGeo POINT feature: ``` class Location < ActiveRecord::Base attr_accessible :latlon, :name, :address set_rgeo_factory_for_column(:latlon, RGeo::Geographic.spherical_factory(:srid => 4326)) geocoded_by :name_and_address do |obj, results| if geo = results.first obj.latlon = Location.rgeo_factory_for_column(:latlon).point(geo.longitude, geo.latitude) end end after_initialize :init after_validation :geocode def init self.latlon ||= Location.rgeo_factory_for_column(:latlon).point(0, 0) end def latitude self.latlon.lat end def latitude=(value) lon = self.latlon.lon self.latlon = Location.rgeo_factory_for_column(:latlon).point(lon, value) end def longitude self.latlon.lon end def longitude=(value) lat = self.latlon.lat self.latlon = Location.rgeo_factory_for_column(:latlon).point(value, lat) end def name_and_address "#{self.name}, #{self.address}" end end ``` In the Rails console I can now do: ``` test = Location.new(name: "Eiffel Tower") // => #<Location id: nil, name: "Eiffel Tower", latlon: #<RGeo::Geographic::SphericalPointImpl:0x81579974 "POINT (0.0 0.0)">, created_at: nil, updated_at: nil, address: nil> test.geocode // => #<RGeo::Geographic::SphericalPointImpl:0x81581ac0 "POINT (2.294254 48.858278)"> ``` Wonderful! However, when I want to save my test Location, which triggers the `:after_validation` call for `:geocode` I get an error: ``` NoMethodError: undefined method `lon' for nil:NilClass from /Users/sg/rails-projects/geo_rails_test/app/models/location.rb:24:in `latitude=' from /Users/sg/rails-projects/geo_rails_test/app/models/location.rb:7:in `block in <class:Location>' from /Users/sg/.rvm/gems/ruby-1.9.3-p194/gems/geocoder-1.1.2/lib/geocoder/stores/base.rb:108:in `call' from /Users/sg/.rvm/gems/ruby-1.9.3-p194/gems/geocoder-1.1.2/lib/geocoder/stores/base.rb:108:in `do_lookup' from /Users/sg/.rvm/gems/ruby-1.9.3-p194/gems/geocoder-1.1.2/lib/geocoder/stores/active_record.rb:278:in `geocode' from /Users/sg/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:405:in `_run__1498365873506454431__validation__51840359655181017__callbacks' [...] ``` It seems that the geocode callback deletes the RGeo object so that its built in methods as well as my getter and setter methods are no longer available. Why? Any ideas?

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