lib/geokit/geocoders/google.rb
module Geokit
module Geocoders
class GoogleGeocoder < Geocoder
config :client_id, :cryptographic_key, :channel, :api_key, :host
self.secure = true
private
# ==== OPTIONS
# * :language - See: https://developers.google.com/maps/documentation/geocoding
# * :result_type - This option allows restricting results by specific result types.
# See https://developers.google.com/maps/documentation/geocoding/intro#reverse-restricted
# Note: This parameter is available only for requests that include an API key or a client ID.
# * :location_type - This option allows restricting results by specific location type.
# See https://developers.google.com/maps/documentation/geocoding/intro#reverse-restricted
# Note: This parameter is available only for requests that include an API key or a client ID.
def self.do_reverse_geocode(latlng, options = {})
latlng = LatLng.normalize(latlng)
latlng_str = "latlng=#{Geokit::Inflector.url_escape(latlng.ll)}"
result_type_str = options[:result_type] ? "&result_type=#{options[:result_type]}" : ''
location_type_str = options[:location_type] ? "&location_type=#{options[:location_type]}" : ''
url = submit_url("#{latlng_str}#{result_type_str}#{location_type_str}", options)
process :json, url
end
# ==== OPTIONS
# * :language - See: https://developers.google.com/maps/documentation/geocoding
# * :bias - This option makes the Google Geocoder return results biased to a particular
# country or viewport. Country code biasing is achieved by passing the ccTLD
# ('uk' for .co.uk, for example) as a :bias value. For a list of ccTLD's,
# look here: http://en.wikipedia.org/wiki/CcTLD. By default, the geocoder
# will be biased to results within the US (ccTLD .com).
#
# If you'd like the Google Geocoder to prefer results within a given viewport,
# you can pass a Geokit::Bounds object as the :bias value.
# * :components - This option allows restricting results by specific areas. See
# https://developers.google.com/maps/documentation/geocoding/intro#ComponentFiltering
# for details.
#
# ==== EXAMPLES
# # By default, the geocoder will return Toledo, OH
# Geokit::Geocoders::GoogleGeocoder.geocode('Toledo').country_code # => 'US'
# # With country code biasing, it returns Toledo (spannish city), Spain
# Geokit::Geocoders::GoogleGeocoder.geocode('Toledo', :bias => :es).country_code # => 'Es'
#
# # By default, the geocoder will return Winnetka, IL
# Geokit::Geocoders::GoogleGeocoder.geocode('Winnetka').state # => 'IL'
# # When biased to an bounding box around California, it will now return the Winnetka neighbourhood, CA
# bounds = Geokit::Bounds.normalize([34.074081, -118.694401], [34.321129, -118.399487])
# Geokit::Geocoders::GoogleGeocoder.geocode('Winnetka', :bias => bounds).state # => 'CA'
#
# # By default, the geocoder will return several matches for Austin with
# the first one being in Texas
# Geokit::Geocoders::GoogleGeocoder.geocode('Austin').state # => 'TX'
# # Using Component Filtering the results can be restricted to a specific
# area, e.g. IL
# Geokit::Geocoders::GoogleGeocoder.geocode('Austin',
# :components => {administrative_area: 'IL', country: 'US'}).state # => 'IL'
def self.do_geocode(address, options = {})
bias_str = options[:bias] ? construct_bias_string_from_options(options[:bias]) : ''
components_str = options[:components] ? construct_components_string_from_options(options[:components]) : ''
address_str = address.is_a?(GeoLoc) ? address.to_geocodeable_s : address
url = submit_url("address=#{Geokit::Inflector.url_escape(address_str)}#{bias_str}#{components_str}", options)
process :json, url
end
# This code comes from Googles Examples
# http://gmaps-samples.googlecode.com/svn/trunk/urlsigning/urlsigner.rb
def self.sign_gmap_bus_api_url(urlToSign, google_cryptographic_key)
require 'base64'
require 'openssl'
# Decode the private key
rawKey = Base64.decode64(google_cryptographic_key.tr('-_', '+/'))
# create a signature using the private key and the URL
rawSignature = OpenSSL::HMAC.digest('sha1', rawKey, urlToSign)
# encode the signature into base64 for url use form.
Base64.encode64(rawSignature).tr('+/', '-_').gsub(/\n/, '')
end
def self.submit_url(query_string, options = {})
language_str = options[:language] ? "&language=#{options[:language]}" : ''
query_string = "/maps/api/geocode/json?sensor=false&#{query_string}#{language_str}"
if client_id && cryptographic_key
channel_string = channel ? "&channel=#{channel}" : ''
urlToSign = query_string + "&client=#{client_id}" + channel_string
signature = sign_gmap_bus_api_url(urlToSign, cryptographic_key)
"#{protocol}://maps.googleapis.com" + urlToSign + "&signature=#{signature}"
elsif api_key
url_with_key = query_string + "&key=#{api_key}"
"#{protocol}://maps.googleapis.com" + url_with_key
else
request_host = host || 'maps.google.com'
"#{protocol}://#{request_host}#{query_string}"
end
end
def self.construct_bias_string_from_options(bias)
case bias
when String, Symbol
# country code biasing
"®ion=#{bias.to_s.downcase}"
when Bounds
# viewport biasing
url_escaped_string = Geokit::Inflector.url_escape("#{bias.sw}|#{bias.ne}")
"&bounds=#{url_escaped_string}"
end
end
def self.construct_components_string_from_options(components={})
unless components.empty?
escaped_components = Geokit::Inflector.url_escape(components.to_a.map { |pair| pair.join(":").downcase }.join("|"))
"&components=#{escaped_components}"
end
end
def self.parse_json(results)
case results['status']
when 'OVER_QUERY_LIMIT'
raise Geokit::Geocoders::TooManyQueriesError, results['error_message']
when 'REQUEST_DENIED'
raise Geokit::Geocoders::AccessDeniedError, results['error_message']
when 'ZERO_RESULTS'
return GeoLoc.new
when 'OK'
# all good
else
raise Geokit::Geocoders::GeocodeError, results['error_message']
end
unsorted = results['results'].map do |addr|
single_json_to_geoloc(addr)
end
all = unsorted.sort { |a, b| b.accuracy <=> a.accuracy }
encoded = all.first
encoded.all = all
encoded
end
# location_type stores additional data about the specified location.
# The following values are currently supported:
# "ROOFTOP" indicates that the returned result is a precise geocode
# for which we have location information accurate down to street
# address precision.
# "RANGE_INTERPOLATED" indicates that the returned result reflects an
# approximation (usually on a road) interpolated between two precise
# points (such as intersections). Interpolated results are generally
# returned when rooftop geocodes are unavailable for a street address.
# "GEOMETRIC_CENTER" indicates that the returned result is the
# geometric center of a result such as a polyline (for example, a
# street) or polygon (region).
# "APPROXIMATE" indicates that the returned result is approximate
# these do not map well. Perhaps we should guess better based on size
# of bounding box where it exists? Does it really matter?
ACCURACY = {
'ROOFTOP' => 9,
'RANGE_INTERPOLATED' => 8,
'GEOMETRIC_CENTER' => 5,
'APPROXIMATE' => 4,
}
PRECISIONS = %w(unknown country state city zip zip+4 street address building)
def self.single_json_to_geoloc(addr)
loc = new_loc
loc.success = true
loc.full_address = addr['formatted_address']
set_address_components(loc, addr)
set_precision(loc, addr)
if loc.street_name
loc.street_address = [loc.street_number, loc.street_name].join(' ').strip
end
ll = addr['geometry']['location']
loc.lat = ll['lat'].to_f
loc.lng = ll['lng'].to_f
set_bounds(loc, addr)
loc.place_id = addr['place_id']
loc.formatted_address = addr['formatted_address']
loc
end
def self.set_bounds(loc, addr)
viewport = addr['geometry']['viewport']
ne = Geokit::LatLng.from_json(viewport['northeast'])
sw = Geokit::LatLng.from_json(viewport['southwest'])
loc.suggested_bounds = Geokit::Bounds.new(sw, ne)
end
def self.set_address_components(loc, addr)
addr['address_components'].each do |comp|
types = comp['types']
case
when types.include?('subpremise')
loc.sub_premise = comp['short_name']
when types.include?('street_number')
loc.street_number = comp['short_name']
when types.include?('route')
loc.street_name = comp['long_name']
when types.include?('locality')
loc.city = comp['long_name']
when types.include?('administrative_area_level_1') # state
loc.state_code = comp['short_name']
loc.state_name = comp['long_name']
when types.include?('postal_town')
loc.city = comp['long_name']
when types.include?('postal_code')
loc.zip = comp['long_name']
when types.include?('country')
loc.country_code = comp['short_name']
loc.country = comp['long_name']
when types.include?('administrative_area_level_2')
loc.district = comp['long_name']
loc.county = comp['long_name']
when types.include?('neighborhood')
loc.neighborhood = comp['short_name']
when types.include?('sublocality')
loc.sublocality = comp['long_name']
loc.city = comp['long_name'] if loc.city.nil? # Use sublocality as city if google does not return a city
when types.include?('administrative_area_level_3')
loc.city = comp['long_name'] if loc.city.nil? # Use admin area level 3 as city if google does not return a city
end
end
end
def self.set_precision(loc, addr)
loc.accuracy = ACCURACY[addr['geometry']['location_type']]
loc.precision = PRECISIONS[loc.accuracy]
# try a few overrides where we can
if loc.sub_premise
loc.precision = PRECISIONS[9]
loc.accuracy = 9
end
if loc.street_name && loc.precision == 'city'
loc.precision = PRECISIONS[7]
loc.accuracy = 7
end
if addr['types'].include?('postal_code')
loc.precision = PRECISIONS[6]
loc.accuracy = 6
end
end
end
end
end