How to work with locations (geo) in Tire

Tire currently does not expose the (awesome!) „Geo Location and Search” support in ElasticSearch.

However, it's simple to define proper mappings for you location-based documents, and it's possible to search them, either via the Tire.search DSL method by passing it a Hash, or descending a level down, and using Tire::Configuration.client.get <MY QUERY AS A HASH> method.

The following example illustrates the point:

require 'tire'
require 'active_record'

Tire.index('venues') { delete }

ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ":memory:" )

ActiveRecord::Migration.verbose = false
ActiveRecord::Schema.define(version: 1) do
  create_table :venues do |t|
    t.string   :title, :latitude, :longitude
  end
end

class Venue < ActiveRecord::Base
  include Tire::Model::Search
  include Tire::Model::Callbacks

  tire do
    mapping do
      indexes :title,   type: 'string', analyzer: 'snowball'
      indexes :lat_lon, type: 'geo_point'
    end
  end

  # NOTE The ordering of latitude and longitude for indexing geo points is different
  # based on whether a string or an array is used. The order when using an array 
  # should be [longitude, latitude] versus for a string where it should be "latitude,longitude".
  # See The elasticsearch documentation for more information.
  # http://www.elasticsearch.org/guide/reference/mapping/geo-point-type.html
  def lat_lon
    [latitude, longitude].join(',')
  end

  def to_indexed_json
    to_json(only: ['title'], methods: ['lat_lon'])
  end
end

Venue.create title: 'Pizzeria Pomodoro', latitude: "41.12", longitude: "-71.34"

Venue.tire.index.refresh

# Example 1: Construct the search as a Hash
query = { query: { filtered: { query: { match_all: ''} }, filter: { geo_distance: { distance: '100km', lat_lon: "41,-71" } } } }

puts "", "The query:", '-'*80, query.to_json

s = Tire.search 'venues', query

puts "", "Results:", '-'*80, s.results.inspect

# Example 2: Construct the search using block syntax
s = Venue.tire.search do
  query { all }
  filter :geo_distance, lat_lon: "41,-71", distance: '100km'
end

puts "", "Results:", '-'*80, s.results.inspect