README.md

Geocoder
========

Geocoder is a complete geocoding solution for Ruby. With Rails, it adds geocoding (by street or IP address), reverse geocoding (finding street address based on given coordinates), and distance queries. It's as simple as calling `geocode` on your objects, and then using a scope like `Venue.near("Billings, MT")`.

_Please note that this README is for the current `HEAD` and may document features not present in the latest gem release. For this reason, you may want to instead view the README for your [particular version](https://github.com/alexreisner/geocoder/releases)._


Compatibility
-------------

* Supports multiple Ruby versions: Ruby 1.9.3, 2.x, and JRuby.
* Supports multiple databases: MySQL, PostgreSQL, SQLite, and MongoDB (1.7.0 and higher).
* Supports Rails 3, 4, and 5. If you need to use it with Rails 2 please see the `rails2` branch (no longer maintained, limited feature set).
* Works very well outside of Rails, you just need to install either the `json` (for MRI) or `json_pure` (for JRuby) gem.


Note on Rails 4.1 and Greater
-----------------------------

Due to [a change in ActiveRecord's `count` method](https://github.com/rails/rails/pull/10710) you will need to use `count(:all)` to explicitly count all columns ("*") when using a `near` scope. Using `near` and calling `count` with no argument will cause exceptions in many cases.


Installation
------------

Install Geocoder like any other Ruby gem:

    gem install geocoder

Or, if you're using Rails/Bundler, add this to your Gemfile:

    gem 'geocoder'

and run at the command prompt:

    bundle install


Object Geocoding
----------------

### ActiveRecord

Your model must have two attributes (database columns) for storing latitude and longitude coordinates. By default they should be called `latitude` and `longitude` but this can be changed (see "Model Configuration" below):

    rails generate migration AddLatitudeAndLongitudeToModel latitude:float longitude:float
    rake db:migrate

For geocoding, your model must provide a method that returns an address. This can be a single attribute, but it can also be a method that returns a string assembled from different attributes (eg: `city`, `state`, and `country`).

Next, your model must tell Geocoder which method returns your object's geocodable address:

    geocoded_by :full_street_address   # can also be an IP address
    after_validation :geocode          # auto-fetch coordinates

For reverse geocoding, tell Geocoder which attributes store latitude and longitude:

    reverse_geocoded_by :latitude, :longitude
    after_validation :reverse_geocode  # auto-fetch address

### Mongoid

First, your model must have an array field for storing coordinates:

    field :coordinates, :type => Array

You may also want an address field, like this:

    field :address

but if you store address components (city, state, country, etc) in separate fields you can instead define a method called `address` that combines them into a single string which will be used to query the geocoding service.

Once your fields are defined, include the `Geocoder::Model::Mongoid` module and then call `geocoded_by`:

    include Geocoder::Model::Mongoid
    geocoded_by :address               # can also be an IP address
    after_validation :geocode          # auto-fetch coordinates

Reverse geocoding is similar:

    include Geocoder::Model::Mongoid
    reverse_geocoded_by :coordinates
    after_validation :reverse_geocode  # auto-fetch address

Once you've set up your model you'll need to create the necessary spatial indices in your database:

    rake db:mongoid:create_indexes

Be sure to read _Latitude/Longitude Order_ in the _Notes on MongoDB_ section below on how to properly retrieve latitude/longitude coordinates from your objects.

### MongoMapper

MongoMapper is very similar to Mongoid, just be sure to include `Geocoder::Model::MongoMapper`.

### Mongo Indices

By default, the methods `geocoded_by` and `reverse_geocoded_by` create a geospatial index. You can avoid index creation with the `:skip_index option`, for example:

    include Geocoder::Model::Mongoid
    geocoded_by :address, :skip_index => true

### Bulk Geocoding

If you have just added geocoding to an existing application with a lot of objects, you can use this Rake task to geocode them all:

    rake geocode:all CLASS=YourModel

If you need reverse geocoding instead, call the task with REVERSE=true:

    rake geocode:all CLASS=YourModel REVERSE=true

Geocoder will print warnings if you exceed the rate limit for your geocoding service. Some services — Google notably — enforce a per-second limit in addition to a per-day limit. To avoid exceeding the per-second limit, you can add a `SLEEP` option to pause between requests for a given amount of time. You can also load objects in batches to save memory, for example:

    rake geocode:all CLASS=YourModel SLEEP=0.25 BATCH=100

To avoid per-day limit issues (for example if you are trying to geocode thousands of objects and don't want to reach the limit), you can add a `LIMIT` option. Warning: This will ignore the `BATCH` value if provided.

    rake geocode:all CLASS=YourModel LIMIT=1000

### Avoiding Unnecessary API Requests

Geocoding only needs to be performed under certain conditions. To avoid unnecessary work (and quota usage) you will probably want to geocode an object only when:

* an address is present
* the address has been changed since last save (or it has never been saved)

The exact code will vary depending on the method you use for your geocodable string, but it would be something like this:

    after_validation :geocode, if: ->(obj){ obj.address.present? and obj.address_changed? }


Request Geocoding by IP Address
-------------------------------

Geocoder adds `location` and `safe_location` methods to the standard `Rack::Request` object so you can easily look up the location of any HTTP request by IP address. For example, in a Rails controller or a Sinatra app:

    # returns Geocoder::Result object
    result = request.location

**The `location` method is vulnerable to trivial IP address spoofing via HTTP headers.**  If that's a problem for your application, use `safe_location` instead, but be aware that `safe_location` will *not* try to trace a request's originating IP through proxy headers; you will instead get the location of the last proxy the request passed through, if any (excepting any proxies you have explicitly whitelisted in your Rack config).

Note that these methods will usually return `nil` in your test and development environments because things like "localhost" and "0.0.0.0" are not an Internet IP addresses.

See _Advanced Geocoding_ below for more information about `Geocoder::Result` objects.


Location-Aware Database Queries
-------------------------------

### For Mongo-backed models:

Please use MongoDB's [geospatial query language](https://docs.mongodb.org/manual/reference/command/geoNear/). Mongoid also provides [a DSL](http://mongoid.github.io/en/mongoid/docs/querying.html#geo_near) for doing near queries.

### For ActiveRecord models:

To find objects by location, use the following scopes:

    Venue.near('Omaha, NE, US', 20)    # venues within 20 miles of Omaha
    Venue.near([40.71, -100.23], 20)    # venues within 20 miles of a point
    Venue.near([40.71, -100.23], 20, :units => :km)
                                       # venues within 20 kilometres of a point
    Venue.geocoded                     # venues with coordinates
    Venue.not_geocoded                 # venues without coordinates

by default, objects are ordered by distance. To remove the ORDER BY clause use the following:

    Venue.near('Omaha', 20, :order => false)

With geocoded objects you can do things like this:

    if obj.geocoded?
      obj.nearbys(30)                      # other objects within 30 miles
      obj.distance_from([40.714,-100.234]) # distance from arbitrary point to object
      obj.bearing_to("Paris, France")      # direction from object to arbitrary point
    end

Some utility methods are also available:

    # look up coordinates of some location (like searching Google Maps)
    Geocoder.coordinates("25 Main St, Cooperstown, NY")
     => [42.700149, -74.922767]

    # distance between Eiffel Tower and Empire State Building
    Geocoder::Calculations.distance_between([47.858205,2.294359], [40.748433,-73.985655])
     => 3619.77359999382 # in configured units (default miles)

    # find the geographic center (aka center of gravity) of objects or points
    Geocoder::Calculations.geographic_center([city1, city2, [40.22,-73.99], city4])
     => [35.14968, -90.048929]

Please see the code for more methods and detailed information about arguments (eg, working with kilometers).


Distance and Bearing
--------------------

When you run a location-aware query the returned objects have two attributes added to them (only w/ ActiveRecord):

* `obj.distance` - number of miles from the search point to this object
* `obj.bearing` - direction from the search point to this object

Results are automatically sorted by distance from the search point, closest to farthest. Bearing is given as a number of clockwise degrees from due north, for example:

* `0` - due north
* `180` - due south
* `90` - due east
* `270` - due west
* `230.1` - southwest
* `359.9` - almost due north

You can convert these numbers to compass point names by using the utility method provided:

    Geocoder::Calculations.compass_point(355) # => "N"
    Geocoder::Calculations.compass_point(45)  # => "NE"
    Geocoder::Calculations.compass_point(208) # => "SW"

_Note: when using SQLite `distance` and `bearing` values are provided for interface consistency only. They are not very accurate._

To calculate accurate distance and bearing with SQLite or MongoDB:

    obj.distance_to([43.9,-98.6])  # distance from obj to point
    obj.bearing_to([43.9,-98.6])   # bearing from obj to point
    obj.bearing_from(obj2)         # bearing from obj2 to obj

The `bearing_from/to` methods take a single argument which can be: a `[lat,lon]` array, a geocoded object, or a geocodable address (string). The `distance_from/to` methods also take a units argument (`:mi`, `:km`, or `:nm` for nautical miles).


Model Configuration
-------------------

You are not stuck with using the `latitude` and `longitude` database column names (with ActiveRecord) or the `coordinates` array (Mongo) for storing coordinates. For example:

    geocoded_by :address, :latitude  => :lat, :longitude => :lon # ActiveRecord
    geocoded_by :address, :coordinates => :coords                # MongoDB

The `address` method can return any string you'd use to search Google Maps. For example, any of the following are acceptable:

* "714 Green St, Big Town, MO"
* "Eiffel Tower, Paris, FR"
* "Paris, TX, US"

If your model has `street`, `city`, `state`, and `country` attributes you might do something like this:

    geocoded_by :address

    def address
      [street, city, state, country].compact.join(', ')
    end

For reverse geocoding, you can also specify an alternate name attribute where the address will be stored. For example:

    reverse_geocoded_by :latitude, :longitude, :address => :location  # ActiveRecord
    reverse_geocoded_by :coordinates, :address => :loc                # MongoDB

You can also configure a specific lookup for your model which will override the globally-configured lookup. For example:

    geocoded_by :address, :lookup => :yandex

You can also specify a proc if you want to choose a lookup based on a specific property of an object. For example, you can use specialized lookups for different regions:

    geocoded_by :address, :lookup => lambda{ |obj| obj.geocoder_lookup }

    def geocoder_lookup
      if country_code == "RU"
        :yandex
      elsif country_code == "CN"
        :baidu
      else
        :google
      end
    end


Advanced Querying
-----------------

When querying for objects (if you're using ActiveRecord) you can also look within a square rather than a radius (circle) by using the `within_bounding_box` scope:

    distance = 20
    center_point = [40.71, 100.23]
    box = Geocoder::Calculations.bounding_box(center_point, distance)
    Venue.within_bounding_box(box)

This can also dramatically improve query performance, especially when used in conjunction with indexes on the latitude/longitude columns. Note, however, that returned results do not include `distance` and `bearing` attributes. Also note that `#near` performs both bounding box and radius queries for speed.

You can also specify a minimum radius (if you're using ActiveRecord and not Sqlite) to constrain the
lower bound (ie. think of a donut, or ring) by using the `:min_radius` option:

    box = Geocoder::Calculations.bounding_box(center_point, distance, :min_radius => 10.5)

With ActiveRecord, you can specify alternate latitude and longitude column names for a geocoded model (useful if you store multiple sets of coordinates for each object):

    Venue.near("Paris", 50, latitude: :secondary_latitude, longitude: :secondary_longitude)


Advanced Geocoding
------------------

So far we have looked at shortcuts for assigning geocoding results to object attributes. However, if you need to do something fancy, you can skip the auto-assignment by providing a block (takes the object to be geocoded and an array of `Geocoder::Result` objects) in which you handle the parsed geocoding result any way you like, for example:

    reverse_geocoded_by :latitude, :longitude do |obj,results|
      if geo = results.first
        obj.city    = geo.city
        obj.zipcode = geo.postal_code
        obj.country = geo.country_code
      end
    end
    after_validation :reverse_geocode

Every `Geocoder::Result` object, `result`, provides the following data:

* `result.latitude` - float
* `result.longitude` - float
* `result.coordinates` - array of the above two in the form of `[lat,lon]`
* `result.address` - string
* `result.city` - string
* `result.state` - string
* `result.state_code` - string
* `result.postal_code` - string
* `result.country` - string
* `result.country_code` - string

If you're familiar with the results returned by the geocoding service you're using you can access even more data (call the `#data` method of any Geocoder::Result object to get the full parsed response), but you'll need to be familiar with the particular `Geocoder::Result` object you're using and the structure of your geocoding service's responses. (See below for links to geocoding service documentation.)


Geocoding Service ("Lookup") Configuration
------------------------------------------

Geocoder supports a variety of street and IP address geocoding services. The default lookups are `:google` for street addresses and `:freegeoip` for IP addresses. Please see the listing and comparison below for details on specific geocoding services (not all settings are supported by all services).

To create a Rails initializer with an example configuration:

    rails generate geocoder:config

Some common configuration options are:

    # config/initializers/geocoder.rb
    Geocoder.configure(

      # geocoding service (see below for supported options):
      :lookup => :yandex,

      # IP address geocoding service (see below for supported options):
      :ip_lookup => :maxmind,

      # to use an API key:
      :api_key => "...",

      # geocoding service request timeout, in seconds (default 3):
      :timeout => 5,

      # set default units to kilometers:
      :units => :km,

      # caching (see below for details):
      :cache => Redis.new,
      :cache_prefix => "..."

    )

Please see [`lib/geocoder/configuration.rb`](https://github.com/alexreisner/geocoder/blob/master/lib/geocoder/configuration.rb) for a complete list of configuration options. Additionally, some lookups have their own configuration options, some of which are directly supported by Geocoder. For example, to specify a value for Google's `bounds` parameter:

    # with Google:
    Geocoder.search("Paris", :bounds => [[32.1,-95.9], [33.9,-94.3]])

Please see the [source code for each lookup](https://github.com/alexreisner/geocoder/tree/master/lib/geocoder/lookups) to learn about directly supported parameters. Parameters which are not directly supported can be specified using the `:params` option, by which you can pass arbitrary parameters to any geocoding service. For example, to use Nominatim's `countrycodes` parameter:

    # with Nominatim:
    Geocoder.search("Paris", :params => {:countrycodes => "gb,de,fr,es,us"})

Or, to search within a particular region with Google:

    Geocoder.search("...", :params => {:region => "..."})

Or, to use parameters in your model:

    class Venue

      # build an address from street, city, and state attributes
      geocoded_by :address_from_components, :params => {:region => "..."}

      # store the fetched address in the full_address attribute
      reverse_geocoded_by :latitude, :longitude, :address => :full_address, :params => {:region => "..."}
    end


### Configure Multiple Services

You can configure multiple geocoding services at once, like this:

    Geocoder.configure(

      :timeout => 2,
      :cache => Redis.new,

      :yandex => {
        :api_key => "...",
        :timeout => 5
      },

      :baidu => {
        :api_key => "..."
      },

      :maxmind => {
        :api_key => "...",
        :service => :omni
      }

    )

The above combines global and service-specific options and could be useful if you specify different geocoding services for different models or under different conditions. Lookup-specific settings override global settings. In the above example, the timeout for all lookups would be 2 seconds, except for Yandex which would be 5.


### Street Address Services

The following is a comparison of the supported geocoding APIs. The "Limitations" listed for each are a very brief and incomplete summary of some special limitations beyond basic data source attribution. Please read the official Terms of Service for a service before using it.

#### Google (`:google`)

* **API key**: optional, but quota is higher if key is used (use of key requires HTTPS so be sure to set: `:use_https => true` in `Geocoder.configure`)
* **Key signup**: https://console.developers.google.com/flows/enableapi?apiid=geocoding_backend&keyType=SERVER_SIDE
* **Quota**: 2,500 requests/24 hrs, 5 requests/second
* **Region**: world
* **SSL support**: yes (required if key is used)
* **Languages**: see https://developers.google.com/maps/faq#languagesupport
* **Extra options**:
  * `:bounds` - pass SW and NE coordinates as an array of two arrays to bias results towards a viewport
  * `:google_place_id` - pass `true` if search query is a Google Place ID
* **Documentation**: https://developers.google.com/maps/documentation/geocoding/intro
* **Terms of Service**: http://code.google.com/apis/maps/terms.html#section_10_12
* **Limitations**: "You must not use or display the Content without a corresponding Google map, unless you are explicitly permitted to do so in the Maps APIs Documentation, or through written permission from Google." "You must not pre-fetch, cache, or store any Content, except that you may store: (i) limited amounts of Content for the purpose of improving the performance of your Maps API Implementation..."

#### Google Maps API for Work (`:google_premier`)

Similar to `:google`, with the following differences:

* **API key**: required, plus client and channel (set `Geocoder.configure(:lookup => :google_premier, :api_key => [key, client, channel])`)
* **Key signup**: https://developers.google.com/maps/documentation/business/
* **Quota**: 100,000 requests/24 hrs, 10 requests/second

#### Google Places Details (`:google_places_details`)

The [Google Places Details API](https://developers.google.com/places/documentation/details) is not, strictly speaking, a geocoding service. It accepts a Google `place_id` and returns address information, ratings and reviews. A `place_id` can be obtained from the Google Places Search lookup (`:google_places_search`) and should be passed to Geocoder as the first search argument: `Geocoder.search("ChIJhRwB-yFawokR5Phil-QQ3zM", lookup: :google_places_details)`.

* **API key**: required
* **Key signup**: https://code.google.com/apis/console/
* **Quota**: 1,000 request/day, 100,000 after credit card authentication
* **Region**: world
* **SSL support**: yes
* **Languages**: ar, eu, bg, bn, ca, cs, da, de, el, en, en-AU, en-GB, es, eu, fa, fi, fil, fr, gl, gu, hi, hr, hu, id, it, iw, ja, kn, ko, lt, lv, ml, mr, nl, no, pl, pt, pt-BR, pt-PT, ro, ru, sk, sl, sr, sv, tl, ta, te, th, tr, uk, vi, zh-CN, zh-TW (see http://spreadsheets.google.com/pub?key=p9pdwsai2hDMsLkXsoM05KQ&gid=1)
* **Documentation**: https://developers.google.com/places/documentation/details
* **Terms of Service**: https://developers.google.com/places/policies
* **Limitations**: "If your application displays Places API data on a page or view that does not also display a Google Map, you must show a "Powered by Google" logo with that data."

#### Google Places Search (`:google_places_search`)

The [Google Places Search API](https://developers.google.com/places/web-service/search) is the geocoding service of Google Places API. It returns very limited location data, but it also returns a `place_id` which can be used with Google Place Details to get more detailed information. For a comparison between this and the regular Google Geocoding API, see https://maps-apis.googleblog.com/2016/11/address-geocoding-in-google-maps-apis.html

* Same specifications as Google Places Details (see above).

#### Bing (`:bing`)

* **API key**: required (set `Geocoder.configure(:lookup => :bing, :api_key => key)`)
* **Key signup**: https://www.microsoft.com/maps/create-a-bing-maps-key.aspx
* **Quota**: 50,0000 requests/day (Windows app), 125,000 requests/year (non-Windows app)
* **Region**: world
* **SSL support**: no
* **Languages**: ?
* **Documentation**: http://msdn.microsoft.com/en-us/library/ff701715.aspx
* **Terms of Service**: http://www.microsoft.com/maps/product/terms.html
* **Limitations**: No country codes or state names. Must be used on "public-facing, non-password protected web sites," "in conjunction with Bing Maps or an application that integrates Bing Maps."

#### Nominatim (`:nominatim`)

* **API key**: none
* **Quota**: 1 request/second
* **Region**: world
* **SSL support**: no
* **Languages**: ?
* **Documentation**: http://wiki.openstreetmap.org/wiki/Nominatim
* **Terms of Service**: http://wiki.openstreetmap.org/wiki/Nominatim_usage_policy
* **Limitations**: Please limit request rate to 1 per second and include your contact information in User-Agent headers (eg: `Geocoder.configure(:http_headers => { "User-Agent" => "your contact info" })`). [Data licensed under Open Database License (ODbL) (you must provide attribution).](http://www.openstreetmap.org/copyright)

#### PickPoint (`:pickpoint`)

* **API key**: required
* **Key signup**: [https://pickpoint.io](https://pickpoint.io)
* **Quota**: 2500 requests / day for free non-commercial usage, commercial plans are [available](https://pickpoint.io/#pricing). No rate limit.
* **Region**: world
* **SSL support**: required
* **Languages**: worldwide
* **Documentation**: [https://pickpoint.io/api-reference](https://pickpoint.io/api-reference)
* **Limitations**: [Data licensed under Open Database License (ODbL) (you must provide attribution).](http://www.openstreetmap.org/copyright)


#### LocationIQ (`:location_iq`)

* **API key**: required
* **Quota**: 60 requests/minute (2 req/sec, 10k req/day), then [ability to purchase more](http://locationiq.org/#pricing)
* **Region**: world
* **SSL support**: yes
* **Languages**: ?
* **Documentation**: https://locationiq.org/#docs
* **Terms of Service**: https://unwiredlabs.com/tos
* **Limitations**: [Data licensed under Open Database License (ODbL) (you must provide attribution).](https://www.openstreetmap.org/copyright)

#### OpenCageData (`:opencagedata`)

* **API key**: required
* **Key signup**: http://geocoder.opencagedata.com
* **Quota**: 2500 requests / day, then [ability to purchase more](https://geocoder.opencagedata.com/pricing)
* **Region**: world
* **SSL support**: yes
* **Languages**: worldwide
* **Documentation**: http://geocoder.opencagedata.com/api.html
* **Limitations**: [Data licensed under Open Database License (ODbL) (you must provide attribution).](http://www.openstreetmap.org/copyright)

#### Yandex (`:yandex`)

* **API key**: optional, but without it lookup is territorially limited
* **Quota**: 25000 requests / day
* **Region**: world with API key. Otherwise restricted to Russia, Ukraine, Belarus, Kazakhstan, Georgia, Abkhazia, South Ossetia, Armenia, Azerbaijan, Moldova, Turkmenistan, Tajikistan, Uzbekistan, Kyrgyzstan and Turkey
* **SSL support**: HTTPS only
* **Languages**: Russian, Belarusian, Ukrainian, English, Turkish (only for maps of Turkey)
* **Documentation**: http://api.yandex.com.tr/maps/doc/intro/concepts/intro.xml
* **Terms of Service**: http://api.yandex.com.tr/maps/doc/intro/concepts/intro.xml#rules
* **Limitations**: ?

#### Geocoder.ca (`:geocoder_ca`)

* **API key**: none
* **Quota**: ?
* **Region**: US and Canada
* **SSL support**: no
* **Languages**: English
* **Documentation**: ?
* **Terms of Service**: http://geocoder.ca/?terms=1
* **Limitations**: "Under no circumstances can our data be re-distributed or re-sold by anyone to other parties without our written permission."

#### Mapbox (`:mapbox`)

* **API key**: required
* **Dataset**: Uses `mapbox.places` dataset by default.  Specify the `mapbox.places-permanent` dataset by setting: `Geocoder.configure(:mapbox => {:dataset => "mapbox.places-permanent"})`
* **Key signup**: https://www.mapbox.com/pricing/
* **Quota**: depends on plan
* **Region**: complete coverage of US and Canada, partial coverage elsewhere (see for details: https://www.mapbox.com/developers/api/geocoding/#coverage)
* **SSL support**: yes
* **Languages**: English
* **Documentation**: https://www.mapbox.com/developers/api/geocoding/
* **Terms of Service**: https://www.mapbox.com/tos/
* **Limitations**: For `mapbox.places` dataset, must be displayed on a Mapbox map; Cache results for up to 30 days. For `mapbox.places-permanent` dataset, depends on plan.
* **Notes**: Currently in public beta.

#### Mapquest (`:mapquest`)

* **API key**: required
* **Key signup**: https://developer.mapquest.com/plans
* **Quota**: ?
* **HTTP Headers**: when using the licensed API you can specify a referer like so:
    `Geocoder.configure(:http_headers => { "Referer" => "http://foo.com" })`
* **Region**: world
* **SSL support**: no
* **Languages**: English
* **Documentation**: http://www.mapquestapi.com/geocoding/
* **Terms of Service**: http://info.mapquest.com/terms-of-use/
* **Limitations**: ?
* **Notes**: You can use the open (non-licensed) API by setting: `Geocoder.configure(:mapquest => {:open => true})` (defaults to licensed version)

#### Ovi/Nokia (`:ovi`)

* **API key**: not required, but performance restricted without it
* **Quota**: ?
* **Region**: world
* **SSL support**: no
* **Languages**: English
* **Documentation**: http://api.maps.ovi.com/devguide/overview.html
* **Terms of Service**: http://www.developer.nokia.com/Develop/Maps/TC.html
* **Limitations**: ?

#### Here/Nokia (`:here`)

* **API key**: required (set `Geocoder.configure(:api_key => [app_id, app_code])`)
* **Quota**: Depending on the API key
* **Region**: world
* **SSL support**: yes
* **Languages**: The preferred language of address elements in the result. Language code must be provided according to RFC 4647 standard.
* **Documentation**: http://developer.here.com/rest-apis/documentation/geocoder
* **Terms of Service**: http://developer.here.com/faqs#l&t
* **Limitations**: ?

#### ESRI (`:esri`)

* **API key**: optional (set `Geocoder.configure(:esri => {:api_key => ["client_id", "client_secret"]})`)
* **Quota**: Required for some scenarios (see Terms of Service)
* **Region**: world
* **SSL support**: yes
* **Languages**: English
* **Documentation**: https://developers.arcgis.com/rest/geocode/api-reference/overview-world-geocoding-service.htm
* **Terms of Service**: http://www.esri.com/legal/software-license
* **Limitations**: Requires API key if results will be stored. Using API key will also remove rate limit.
* **Notes**: You can specify which projection you want to use by setting, for example: `Geocoder.configure(:esri => {:outSR => 102100})`. If you will store results, set the flag and provide API key: `Geocoder.configure(:esri => {:api_key => ["client_id", "client_secret"], :for_storage => true})`. If you want to, you can also supply an ESRI token directly: `Geocoder.configure(:esri => {:token => Geocoder::EsriToken.new('TOKEN', Time.now + 1.day})`

#### Mapzen (`:mapzen`)

* **API key**: required
* **Quota**: 6/sec, up to 30k per day, paid plan info at https://mapzen.com/documentation/search/api-keys-rate-limits/#rate-limits
* **Region**: world
* **SSL support**: yes
* **Languages**: en
* **Documentation**: https://mapzen.com/documentation/search/search/
* **Terms of Service**: http://mapzen.com/terms
* **Limitations**: ?
* **Notes**: Mapzen is the primary author of Pelias and offers Pelias-as-a-service in free and paid versions https://mapzen.com/pelias.

#### Pelias (`:pelias`)

* **API key**: configurable (self-hosted service)
* **Quota**: none (self-hosted service)
* **Region**: world
* **SSL support**: yes
* **Languages**: en
* **Documentation**: https://github.com/pelias/pelias
* **Terms of Service**: https://github.com/pelias/pelias/blob/master/data_licenses.md
* **Limitations**: See terms
* **Notes**: Configure your self-hosted pelias with the `endpoint` option: `Geocoder.configure(:lookup => :pelias, :api_key => 'your_api_key', :pelias => {:endpoint => 'self.hosted/pelias'})`. Defaults to `localhost`.

#### Data Science Toolkit (`:dstk`)

Data Science Toolkit provides an API whose response format is like Google's but which can be set up as a privately hosted service.

* **API key**: none
* **Quota**: No quota if you are self-hosting the service.
* **Region**: world
* **SSL support**: ?
* **Languages**: en
* **Documentation**: http://www.datasciencetoolkit.org/developerdocs
* **Terms of Service**: http://www.datasciencetoolkit.org/developerdocs#googlestylegeocoder
* **Limitations**: No reverse geocoding.
* **Notes**: If you are hosting your own DSTK server you will need to configure the host name, eg: `Geocoder.configure(:lookup => :dstk, :dstk => {:host => "localhost:4567"})`.

#### Baidu (`:baidu`)

* **API key**: required
* **Quota**: No quota limits for geocoding
* **Region**: China
* **SSL support**: no
* **Languages**: Chinese (Simplified)
* **Documentation**: http://developer.baidu.com/map/webservice-geocoding.htm
* **Terms of Service**: http://developer.baidu.com/map/law.htm
* **Limitations**: Only good for non-commercial use. For commercial usage please check http://developer.baidu.com/map/question.htm#qa0013
* **Notes**: To use Baidu set `Geocoder.configure(:lookup => :baidu, :api_key => "your_api_key")`.

#### Geocodio (`:geocodio`)

* **API key**: required
* **Quota**: 2,500 free requests/day then purchase $0.0005 for each, also has volume pricing and plans. Pricing page: https://geocod.io/pricing/
* **Region**: US
* **SSL support**: yes
* **Languages**: en
* **Documentation**: http://geocod.io/docs
* **Terms of Service**: http://geocod.io/terms-of-use
* **Limitations**: No restrictions on use

#### SmartyStreets (`:smarty_streets`)

* **API key**: requires auth_id and auth_token (set `Geocoder.configure(:api_key => [id, token])`)
* **Quota**: 250/month then purchase at sliding scale. Pricing page: https://smartystreets.com/pricing
* **Region**: US
* **SSL support**: yes (required)
* **Languages**: en
* **Documentation**: http://smartystreets.com/kb/liveaddress-api/rest-endpoint
* **Terms of Service**: http://smartystreets.com/legal/terms-of-service
* **Limitations**: No reverse geocoding.


#### OKF Geocoder (`:okf`)

* **API key**: none
* **Quota**: none
* **Region**: FI
* **SSL support**: no
* **Languages**: fi
* **Documentation**: http://books.okf.fi/geocoder/_full/
* **Terms of Service**: http://www.itella.fi/liitteet/palvelutjatuotteet/yhteystietopalvelut/Postinumeropalvelut-Palvelukuvausjakayttoehdot.pdf
* **Limitations**: ?

#### Geoportail.lu (`:geoportail_lu`)

* **API key**: none
* **Quota**: none
* **Region**: LU
* **SSL support**: yes
* **Languages**: en
* **Documentation**: http://wiki.geoportail.lu/doku.php?id=en:api
* **Terms of Service**: http://wiki.geoportail.lu/doku.php?id=en:mcg_1
* **Limitations**: ?

#### PostcodeAnywhere Uk (`:postcode_anywhere_uk`)

This uses the PostcodeAnywhere UK Geocode service, this will geocode any string from UK postcode, placename, point of interest or location.

* **API key**: required
* **Quota**: Dependant on service plan?
* **Region**: UK
* **SSL support**: yes
* **Languages**: English
* **Documentation**: [http://www.postcodeanywhere.co.uk/Support/WebService/Geocoding/UK/Geocode/2/](http://www.postcodeanywhere.co.uk/Support/WebService/Geocoding/UK/Geocode/2/)
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: To use PostcodeAnywhere you must include an API key: `Geocoder.configure(:lookup => :postcode_anywhere_uk, :api_key => 'your_api_key')`.

#### LatLon.io (`:latlon`)

* **API key**: required
* **Quota**: Depends on the user's plan (free and paid plans available)
* **Region**: US
* **SSL support**: yes
* **Languages**: en
* **Documentation**: https://latlon.io/documentation
* **Terms of Service**: ?
* **Limitations**: No restrictions on use

#### Base Adresse Nationale FR (`:ban_data_gouv_fr`)

* **API key**: none
* **Quota**: none
* **Region**: FR
* **SSL support**: yes
* **Languages**: en / fr
* **Documentation**: https://adresse.data.gouv.fr/api/ (in french)
* **Terms of Service**: https://adresse.data.gouv.fr/faq/ (in french)
* **Limitations**: [Data licensed under Open Database License (ODbL) (you must provide attribution).](http://openstreetmap.fr/ban)

#### AMap (`:amap`)

- **API key**: required
- **Quota**: 2000/day and 2000/minute for personal developer, 4000000/day and 60000/minute for enterprise developer, for geocoding requests
- **Region**: China
- **SSL support**: yes
- **Languages**: Chinese (Simplified)
- **Documentation**: http://lbs.amap.com/api/webservice/guide/api/georegeo
- **Terms of Service**: http://lbs.amap.com/home/terms/
- **Limitations**: Only good for non-commercial use. For commercial usage please check http://lbs.amap.com/home/terms/
- **Notes**: To use AMap set `Geocoder.configure(:lookup => :amap, :api_key => "your_api_key")`.

### IP Address Services

#### FreeGeoIP (`:freegeoip`)

* **API key**: none
* **Quota**: 15,000 requests per hour. After reaching the hourly quota, all of your requests will result in HTTP 403 (Forbidden) until it clears up on the next roll over.
* **Region**: world
* **SSL support**: no
* **Languages**: English
* **Documentation**: http://github.com/fiorix/freegeoip/blob/master/README.md
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: If you are [running your own local instance of the FreeGeoIP service](https://github.com/fiorix/freegeoip) you can configure the host like this: `Geocoder.configure(freegeoip: {host: "..."})`.

#### Pointpin (`:pointpin`)

* **API key**: required
* **Quota**: 50,000/mo for €9 through 1m/mo for €49
* **Region**: world
* **SSL support**: yes
* **Languages**: English
* **Documentation**: https://pointp.in/docs/get-started
* **Terms of Service**: https://pointp.in/terms
* **Limitations**: ?
* **Notes**: To use Pointpin set `Geocoder.configure(:ip_lookup => :pointpin, :api_key => "your_pointpin_api_key")`.

#### Telize (`:telize`)

* **API key**: required
* **Quota**: 1,000/day for $7/mo through 100,000/day for $100/mo
* **Region**: world
* **SSL support**: yes
* **Languages**: English
* **Documentation**: https://market.mashape.com/fcambus/telize
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: To use Telize set `Geocoder.configure(:ip_lookup => :telize, :api_key => "your_api_key")`. Or configure your self-hosted telize with the `host` option: `Geocoder.configure(:ip_lookup => :telize, :telize => {:host => "localhost"})`.


#### MaxMind Legacy Web Services (`:maxmind`)

* **API key**: required
* **Quota**: Request Packs can be purchased
* **Region**: world
* **SSL support**: yes
* **Languages**: English
* **Documentation**: http://dev.maxmind.com/geoip/legacy/web-services/
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: You must specify which MaxMind service you are using in your configuration. For example: `Geocoder.configure(:maxmind => {:service => :omni})`.

#### Baidu IP (`:baidu_ip`)

* **API key**: required
* **Quota**: No quota limits for geocoding
* **Region**: China
* **SSL support**: no
* **Languages**: Chinese (Simplified)
* **Documentation**: http://developer.baidu.com/map/webservice-geocoding.htm
* **Terms of Service**: http://developer.baidu.com/map/law.htm
* **Limitations**: Only good for non-commercial use. For commercial usage please check http://developer.baidu.com/map/question.htm#qa0013
* **Notes**: To use Baidu set `Geocoder.configure(:lookup => :baidu_ip, :api_key => "your_api_key")`.

#### MaxMind GeoIP2 Precision Web Services (`:maxmind_geoip2`)

* **API key**: required
* **Quota**: Request Packs can be purchased
* **Region**: world
* **SSL support**: yes
* **Languages**: English
* **Documentation**: http://dev.maxmind.com/geoip/geoip2/web-services/
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: You must specify which MaxMind service you are using in your configuration, and also basic authentication. For example: `Geocoder.configure(:maxmind_geoip2 => {:service => :country, :basic_auth => {:user => '', :password => ''}})`.

#### IPInfo.io (`:ipinfo_io`)

* **API key**: optional - see http://ipinfo.io/pricing
* **Quota**: 1,000/day - more with api key
* **Region**: world
* **SSL support**: no (not without access key - see http://ipinfo.io/pricing)
* **Languages**: English
* **Documentation**: http://ipinfo.io/developers
* **Terms of Service**: http://ipinfo.io/developers

#### IP-API.com (`:ipapi_com`)

* **API key**: optional - see http://ip-api.com/docs/#usage_limits
* **Quota**: 150/minute - unlimited with api key
* **Region**: world
* **SSL support**: no (not without access key - see https://signup.ip-api.com/)
* **Languages**: English
* **Documentation**: http://ip-api.com/docs/
* **Terms of Service**: https://signup.ip-api.com/terms

#### DB-IP.com (`:db_ip_com`)

* **API key**: required
* **Quota**: 2,500/day (with free API Key, 50,000/day and up for paid API keys)
* **Region**: world
* **SSL support**: yes (with paid API keys - see https://db-ip.com/api/)
* **Languages**: English (English with free API key, multiple languages with paid API keys)
* **Documentation**: https://db-ip.com/api/doc.php
* **Terms of Service**: https://db-ip.com/tos.php

### IP Address Local Database Services

#### MaxMind Local (`:maxmind_local`) - EXPERIMENTAL

This lookup provides methods for geocoding IP addresses without making a call to a remote API (improves speed and availability). It works, but support is new and should not be considered production-ready. Please [report any bugs](https://github.com/alexreisner/geocoder/issues) you encounter.

* **API key**: none (requires the GeoLite City database which can be downloaded from [MaxMind](http://dev.maxmind.com/geoip/legacy/geolite/))
* **Quota**: none
* **Region**: world
* **SSL support**: N/A
* **Languages**: English
* **Documentation**: http://www.maxmind.com/en/city
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: There are two supported formats for MaxMind local data: binary file, and CSV file imported into an SQL database. **You must download a database from MaxMind and set either the `:file` or `:package` configuration option for local lookups to work.**

**To use a binary file** you must add the *geoip* (or *jgeoip* for JRuby) gem to your Gemfile or have it installed in your system, and specify the path of the MaxMind database in your configuration. For example:

    Geocoder.configure(ip_lookup: :maxmind_local, maxmind_local: {file: File.join('folder', 'GeoLiteCity.dat')})

**To use a CSV file** you must import it into an SQL database. The GeoLite *City* and *Country* packages are supported. Configure like so:

    Geocoder.configure(ip_lookup: :maxmind_local, maxmind_local: {package: :city})

You can generate ActiveRecord migrations and download and import data via provided rake tasks:

    # generate migration to create tables
    rails generate geocoder:maxmind:geolite_city

    # download, unpack, and import data
    rake geocoder:maxmind:geolite:load PACKAGE=city

You can replace `city` with `country` in any of the above tasks, generators, and configurations.

#### GeoLite2 (`:geoip2`)

This lookup provides methods for geocoding IP addresses without making a call to a remote API (improves speed and availability). It works, but support is new and should not be considered production-ready. Please [report any bugs](https://github.com/alexreisner/geocoder/issues) you encounter.

* **API key**: none (requires a GeoIP2 or free GeoLite2 City or Country binary database which can be downloaded from [MaxMind](http://dev.maxmind.com/geoip/geoip2/))
* **Quota**: none
* **Region**: world
* **SSL support**: N/A
* **Languages**: English
* **Documentation**: http://www.maxmind.com/en/city
* **Terms of Service**: ?
* **Limitations**: ?
* **Notes**: **You must download a binary database file from MaxMind and set the `:file` configuration option.** The CSV format databases are not yet supported since they are still in alpha stage. Set the path to the database file in your configuration:

    Geocoder.configure(
      ip_lookup: :geoip2,
      geoip2: {
        file: File.join('folder', 'GeoLite2-City.mmdb')
      }
    )

You must add either the *[hive_geoip2](https://rubygems.org/gems/hive_geoip2)* gem (native extension that relies on libmaxminddb) or the *[maxminddb](http://rubygems.org/gems/maxminddb)* gem (pure Ruby implementation) to your Gemfile or have it installed in your system. The pure Ruby gem (maxminddb) will be used by default. To use `hive_geoip2`:

    Geocoder.configure(
      ip_lookup: :geoip2,
      geoip2: {
        lib: 'hive_geoip2',
        file: File.join('folder', 'GeoLite2-City.mmdb')
      }
    )

Caching
-------

When relying on any external service, it's always a good idea to cache retrieved data. When implemented correctly, it improves your app's response time and stability. It's easy to cache geocoding results with Geocoder -- just configure a cache store:

    Geocoder.configure(:cache => Redis.new)

This example uses Redis, but the cache store can be any object that supports these methods:

* `store#[](key)` or `#get` or `#read` - retrieves a value
* `store#[]=(key, value)` or `#set` or `#write` - stores a value
* `store#del(url)` - deletes a value
* `store#keys` - (Optional) Returns array of keys. Used if you wish to expire the entire cache (see below).

Even a plain Ruby hash will work, though it's not a great choice (cleared out when app is restarted, not shared between app instances, etc).

You can also set a custom prefix to be used for cache keys:

    Geocoder.configure(:cache_prefix => "...")

By default the prefix is `geocoder:`

If you need to expire cached content:

    Geocoder::Lookup.get(Geocoder.config[:lookup]).cache.expire(:all)  # expire cached results for current Lookup
    Geocoder::Lookup.get(:google).cache.expire("http://...")           # expire cached result for a specific URL
    Geocoder::Lookup.get(:google).cache.expire(:all)                   # expire cached results for Google Lookup
    # expire all cached results for all Lookups.
    # Be aware that this methods spawns a new Lookup object for each Service
    Geocoder::Lookup.all_services.each{|service| Geocoder::Lookup.get(service).cache.expire(:all)}

Do *not* include the prefix when passing a URL to be expired. Expiring `:all` will only expire keys with the configured prefix -- it will *not* expire every entry in your key/value store.

For an example of a cache store with URL expiry, please see examples/autoexpire_cache.rb

_Before you implement caching in your app please be sure that doing so does not violate the Terms of Service for your geocoding service._


Forward and Reverse Geocoding in the Same Model
-----------------------------------------------

If you apply both forward and reverse geocoding functionality to the same model (i.e. users can supply an address or coordinates and you want to fill in whatever's missing), you will provide two address methods:

* one for storing the fetched address (reverse geocoding)
* one for providing an address to use when fetching coordinates (forward geocoding)

For example:

    class Venue

      # build an address from street, city, and state attributes
      geocoded_by :address_from_components

      # store the fetched address in the full_address attribute
      reverse_geocoded_by :latitude, :longitude, :address => :full_address
    end

However, there can be only one set of latitude/longitude attributes, and whichever you specify last will be used. For example:

    class Venue

      geocoded_by :address,
        :latitude  => :fetched_latitude,  # this will be overridden by the below
        :longitude => :fetched_longitude  # same here

      reverse_geocoded_by :latitude, :longitude
    end

We don't want ambiguity when doing distance calculations -- we need a single, authoritative source for coordinates!

Once both forward and reverse geocoding has been applied, it is possible to call them sequentially.

For example:

    class Venue

      after_validation :geocode, :reverse_geocode

    end

For certain geolocation services such as Google's geolocation API, this may cause issues during subsequent updates to database records if the longitude and latitude coordinates cannot be associated with a known location address (on a large body of water for example). On subsequent callbacks the following call:

     after_validation :geocode