diff --git a/README.md b/README.md new file mode 100644 index 0000000000000000000000000000000000000000..b2e6b739e93936b42c0316e399bd7873bdcbf718 --- /dev/null +++ b/README.md @@ -0,0 +1,580 @@ +Geocoder +======== + +Geocoder is a complete geocoding solution for Ruby. With Rails it adds geocoding (by street or IP address), reverse geocoding (find 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")`. + + +Compatibility +------------- + +* Supports multiple Ruby versions: Ruby 1.8.7, 1.9.2, and JRuby. +* Supports multiple databases: MySQL, PostgreSQL, SQLite, and MongoDB (1.7.0 and higher). +* Supports Rails 3. If you need to use it with Rails 2 please see the `rails2` branch (no longer maintained, limited feature set).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. + + +Install +------- + +### As a Gem + +Add to your Gemfile: + + gem "geocoder" + +and run at the command prompt: + + bundle install + +### Or As a Plugin + +At the command prompt: + + rails plugin install git://github.com/alexreisner/geocoder.git + + +Configure Object Geocoding +-------------------------- + +In the below, note that addresses may be street or IP addresses. + +### 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 "More on Configuration" below): + + rails generate migration AddLatitudeAndLongitudeToModel latitude:float longitude:float + rake db:migrate + +For reverse 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 + +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 + +Geocoder will print warnings if you exceed the rate limit for your geocoding service. + + +Request Geocoding by IP Address +------------------------------- + +Geocoder adds a `location` method 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 + +See _Advanced Geocoding_ below for more information about `Geocoder::Result` objects. + + +Location-Aware Database Queries +------------------------------- + +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.geocoded # venues with coordinates + Venue.not_geocoded # venues without coordinates + +With geocoded objects you can do things like this: + + 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 + +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 (in miles) between Eiffel Tower and Empire State Building + Geocoder::Calculations.distance_between([47.858205,2.294359], [40.748433,-73.985655]) + => 3619.77359999382 + + # 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` or `:km`). + + +More on 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 + + +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. If you want to improve performance AND have access to distance and bearing info, use both scopes: + + Venue.near(center_point, distance).within_bounding_box(box) + + +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 +* `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, 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 Services +------------------ + +By default Geocoder uses Google's geocoding API to fetch coordinates and street addresses (FreeGeoIP is used for IP address info). However there are several other APIs supported, as well as a variety of settings. Please see the listing and comparison below for details on specific geocoding services (not all settings are supported by all services). Some common configuration options are: + + # config/initializers/geocoder.rb + Geocoder.configure do |config| + + # geocoding service (see below for supported options): + config.lookup = :yahoo + + # to use an API key: + config.api_key = "..." + + # geocoding service request timeout, in seconds (default 3): + config.timeout = 5 + + # set default units to kilometers: + config.units = :km + + # caching (see below for details): + config.cache = Redis.new + config.cache_prefix = "..." + + end + +Please see lib/geocoder/configuration.rb for a complete list of configuration options. Additionally, some lookups have their own configuration options which are listed in the comparison chart below, and as of version 1.2.0 you can pass arbitrary parameters to any geocoding service. For example, to use Nominatim's `countrycodes` parameter: + + Geocoder::Configuration.lookup = :nominatim + Geocoder.search("Paris", :params => {:countrycodes => "gb,de,fr,es,us"}) + + +### Listing and Comparison + +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`, `:google_premier`) + +* **API key**: required for Premier (do NOT use a key for the free version) +* **Key signup**: http://code.google.com/apis/maps/signup.html +* **Quota**: 2,500 requests/day, 100,000 with Google Maps API Premier +* **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) +* **Extra options**: `:bounds` - pass SW and NE coordinates as an array of two arrays to bias results towards a viewport +* **Documentation**: http://code.google.com/apis/maps/documentation/geocoding/#JSON +* **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..." +* **Notes**: To use Google Premier set `Geocoder::Configuration.lookup = :google_premier` and `Geocoder::Configuration.api_key = [key, client, channel]`. + +#### Yahoo (`:yahoo`) + +* **API key**: optional in development (required for production apps) +* **Key signup**: https://developer.apps.yahoo.com/wsregapp +* **Quota**: 50,000 requests/day, more available by special arrangement +* **Region**: world +* **SSL support**: no +* **Languages**: ? +* **Documentation**: http://developer.yahoo.com/geo/placefinder/guide/responses.html +* **Terms of Service**: http://info.yahoo.com/legal/us/yahoo/maps/mapsapi/mapsapi-2141.html +* **Limitations**: "YOU SHALL NOT... (viii) store or allow end users to store map imagery, map data or geocoded location information from the Yahoo! Maps APIs for any future use; (ix) use the stand-alone geocoder for any use other than displaying Yahoo! Maps or displaying points on Yahoo! Maps;" + +#### Bing (`:bing`) + +* **API key**: required +* **Key signup**: http://www.bingmapsportal.com +* **Quota**: 50,000 requests/24 hrs +* **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. Data licensed under CC-BY-SA (you must provide attribution). + +#### Yandex (`:yandex`) + +* **API key**: none +* **Quota**: 25000 requests / day +* **Region**: world +* **SSL support**: no +* **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." + +#### Mapquest (`:mapquest`) + +* **API key**: none +* **Quota**: ? +* **Region**: world +* **SSL support**: no +* **Languages**: English +* **Documentation**: http://www.mapquestapi.com/geocoding/ +* **Terms of Service**: http://info.mapquest.com/terms-of-use/ +* **Limitations**: ? + +#### FreeGeoIP (`:freegeoip`) + +* **API key**: none +* **Quota**: 1000 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.rst +* **Terms of Service**: ? +* **Limitations**: ? + + +Caching +------- + +It's a good idea, when relying on any external service, 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::Configuration.cache = Redis.new + +This example uses Redis, but the cache store can be any object that supports these methods: + +* `store#[](key)` - retrieves a value +* `store#[]=(key, value)` - stores a value +* `store#keys` - lists all keys +* `store#del(url)` - deletes a value + +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::Configuration.cache_prefix = "..." + +By default the prefix is `geocoder:` + +If you need to expire cached content: + + Geocoder.cache.expire("http://...") # expire cached result for a URL + Geocoder.cache.expire(:all) # expire all cached results + +Do *not* include the prefix when passing a URL to be expired. Expiring `:all` will only expire keys with the configured prefix (won't kill 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 (say 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 + +The reason for this is that we don't want ambiguity when doing distance calculations. We need a single, authoritative source for coordinates! + + +Use Outside of Rails +-------------------- + +You can use Geocoder outside of Rails by calling the `Geocoder.search` method: + + results = Geocoder.search("McCarren Park, Brooklyn, NY") + +This returns an array of `Geocoder::Result` objects with all information provided by the geocoding service. Please see above and in the code for details. + + +Testing Apps that Use Geocoder +------------------------------ + +When writing tests for an app that uses Geocoder it may be useful to avoid network calls and have Geocoder return consistent, configurable results. To do this, configure and use the `:test` lookup. For example: + + Geocoder::Configuration.lookup = :test + + Geocoder::Lookup::Test.add_stub( + "New York, NY", [ + { + 'latitude' => 40.7143528, + 'longitude' => -74.0059731, + 'address' => 'New York, NY, USA', + 'state' => 'New York', + 'state_code' => 'NY', + 'country' => 'United States', + 'country_code' => 'US' + } + ] + ) + +Now, any time Geocoder looks up "New York, NY" its results array will contain one result with the above attributes. + + +Command Line Interface +---------------------- + +When you install the Geocoder gem it adds a `geocode` command to your shell. You can search for a street address, IP address, postal code, coordinates, etc just like you can with the Geocoder.search method for example: + + $ geocode 29.951,-90.081 + Latitude: 29.952211 + Longitude: -90.080563 + Full address: 1500 Sugar Bowl Dr, New Orleans, LA 70112, USA + City: New Orleans + State/province: Louisiana + Postal code: 70112 + Country: United States + Google map: http://maps.google.com/maps?q=29.952211,-90.080563 + +There are also a number of options for setting the geocoding API, key, and language, viewing the raw JSON reponse, and more. Please run `geocode -h` for details. + + +Notes on MongoDB +---------------- + +### The Near Method + +Mongo document classes (Mongoid and MongoMapper) have a built-in `near` scope, but since it only works two-dimensions Geocoder overrides it with its own spherical `near` method in geocoded classes. + +### Latitude/Longitude Order + +Coordinates are generally printed and spoken as latitude, then longitude ([lat,lon]). Geocoder respects this convention and always expects method arguments to be given in [lat,lon] order. However, MongoDB requires that coordinates be stored in [lon,lat] order as per the GeoJSON spec (http://geojson.org/geojson-spec.html#positions), so internally they are stored "backwards." However, this does not affect order of arguments to methods when using Mongoid or MongoMapper. + +To access an object's coordinates in the conventional order, use the `to_coordinates` instance method provided by Geocoder. For example: + + obj.to_coordinates # => [37.7941013, -122.3951096] # [lat, lon] + +Calling `obj.coordinates` directly returns the internal representation of the coordinates which, in the case of MongoDB, is probably the reverse of what you want: + + obj.coordinates # => [-122.3951096, 37.7941013] # [lon, lat] + +For consistency with the rest of Geocoder, always use the `to_coordinates` method instead. + + +Distance Queries in SQLite +-------------------------- + +SQLite's lack of trigonometric functions requires an alternate implementation of the `near` scope. When using SQLite, Geocoder will automatically use a less accurate algorithm for finding objects near a given point. Results of this algorithm should not be trusted too much as it will return objects that are outside the given radius, along with inaccurate distance and bearing calculations. + + +### Discussion + +There are few options for finding objects near a given point in SQLite without installing extensions: + +1. Use a square instead of a circle for finding nearby points. For example, if you want to find points near 40.71, 100.23, search for objects with latitude between 39.71 and 41.71 and longitude between 99.23 and 101.23. One degree of latitude or longitude is at most 69 miles so divide your radius (in miles) by 69.0 to get the amount to add and subtract from your center coordinates to get the upper and lower bounds. The results will not be very accurate (you'll get points outside the desired radius), but you will get all the points within the required radius. + +2. Load all objects into memory and compute distances between them using the `Geocoder::Calculations.distance_between` method. This will produce accurate results but will be very slow (and use a lot of memory) if you have a lot of objects in your database. + +3. If you have a large number of objects (so you can't use approach #2) and you need accurate results (better than approach #1 will give), you can use a combination of the two. Get all the objects within a square around your center point, and then eliminate the ones that are too far away using `Geocoder::Calculations.distance_between`. + +Because Geocoder needs to provide this functionality as a scope, we must go with option #1, but feel free to implement #2 or #3 if you need more accuracy. + + +Tests +----- + +Geocoder comes with a test suite (just run `rake test`) that mocks ActiveRecord and is focused on testing the aspects of Geocoder that do not involve executing database queries. Geocoder uses many database engine-specific queries which must be tested against all supported databases (SQLite, MySQL, etc). Ideally this involves creating a full, working Rails application, and that seems beyond the scope of the included test suite. As such, I have created a separate repository which includes a full-blown Rails application and some utilities for easily running tests against multiple environments: + +http://github.com/alexreisner/geocoder_test + + +Error Handling +-------------- + +By default Geocoder will rescue any exceptions raised by calls to the geocoding service and return an empty array (using warn() to inform you of the error). You can override this and implement custom error handling for certain exceptions by using the `:always_raise` option: + + Geocoder::Configuration.always_raise = [SocketError, TimeoutError] + +You can also do this to raise all exceptions: + + Geocoder::Configuration.always_raise = :all + +See `lib/geocoder/exceptions.rb` for a list of raise-able exceptions. + + +Known Issue +----------- + +You cannot use the `near` scope with another scope that provides an `includes` option because the `SELECT` clause generated by `near` will overwrite it (or vice versa). Instead, try using `joins` and pass a `:select` option to the `near` scope to get the columns you want. For example: + + # instead of City.near(...).includes(:venues) + City.near("Omaha, NE", 20, :select => "cities.*, venues.*").joins(:venues) + +If anyone has a more elegant solution to this problem I am very interested in seeing it. + + +Copyright (c) 2009-12 Alex Reisner, released under the MIT license diff --git a/README.rdoc b/README.rdoc deleted file mode 100644 index a82ad48f9d920e55d5694cf106c66eab1d29880b..0000000000000000000000000000000000000000 --- a/README.rdoc +++ /dev/null @@ -1,557 +0,0 @@ -= Geocoder - -Geocoder is a complete geocoding solution for Ruby. With Rails it adds geocoding (by street or IP address), reverse geocoding (find 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 <tt>Venue.near("Billings, MT")</tt>. - - -== Compatibility - -* Supports multiple Ruby versions: Ruby 1.8.7, 1.9.2, and JRuby. -* Supports multiple databases: MySQL, PostgreSQL, SQLite, and MongoDB (1.7.0 and higher). -* Supports Rails 3. If you need to use it with Rails 2 please see the <tt>rails2</tt> 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. - - -== Install - -=== As a Gem - -Add to your Gemfile: - - gem "geocoder" - -and run at the command prompt: - - bundle install - -=== Or As a Plugin - -At the command prompt: - - rails plugin install git://github.com/alexreisner/geocoder.git - - -== Configure Object Geocoding - -In the below, note that addresses may be street or IP addresses. - -=== 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 "More on Configuration" below): - - rails generate migration AddLatitudeAndLongitudeToModel latitude:float longitude:float - rake db:migrate - -For reverse 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 <tt>Geocoder::Model::Mongoid</tt> module and then call <tt>geocoded_by</tt>: - - 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 - -Be sure to read <i>Latitude/Longitude Order</i> in the <i>Notes on MongoDB</i> 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 <tt>Geocoder::Model::MongoMapper</tt>. - -=== Mongo Indices - -By default, the methods <tt>geocoded_by</tt> and <tt>reverse_geocoded_by</tt> create a geospatial index. You can avoid index creation with the <tt>:skip_index option</tt>, 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 - -Geocoder will print warnings if you exceed the rate limit for your geocoding service. - - -== Request Geocoding by IP Address - -Geocoder adds a +location+ method to the standard <tt>Rack::Request</tt> 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 - -See "Advanced Geocoding" below for more information about Geocoder::Result objects. - - -== Location-Aware Database Queries - -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.geocoded # venues with coordinates - Venue.not_geocoded # venues without coordinates - -With geocoded objects you can do things like this: - - 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 - -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 (in miles) between Eiffel Tower and Empire State Building - Geocoder::Calculations.distance_between([47.858205,2.294359], [40.748433,-73.985655]) - => 3619.77359999382 - - # 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): - -* <tt>obj.distance</tt> - number of miles from the search point to this object -* <tt>obj.bearing</tt> - 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: - -* <tt>0</tt> - due north -* <tt>180</tt> - due south -* <tt>90</tt> - due east -* <tt>270</tt> - due west -* <tt>230.1</tt> - southwest -* <tt>359.9</tt> - 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" - -<i>Note: when using SQLite +distance+ and +bearing+ values are provided for interface consistency only. They are not very accurate.</i> - -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 <tt>bearing_from/to</tt> methods take a single argument which can be: a <tt>[lat,lon]</tt> array, a geocoded object, or a geocodable address (string). The <tt>distance_from/to</tt> methods also take a units argument (<tt>:mi</tt> or <tt>:km</tt>). - - -== More on 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 - - -== 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 <tt>within_bounding_box</tt> 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. If you want to improve performance AND have access to distance and bearing info, use both scopes: - - Venue.near(center_point, distance).within_bounding_box(box) - - -== 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 <tt>Geocoder::Result</tt> 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 <tt>Geocoder::Result</tt> object, +result+, provides the following data: - -* <tt>result.latitude</tt> - float -* <tt>result.longitude</tt> - float -* <tt>result.coordinates</tt> - array of the above two -* <tt>result.address</tt> - string -* <tt>result.city</tt> - string -* <tt>result.state</tt> - string -* <tt>result.state_code</tt> - string -* <tt>result.postal_code</tt> - string -* <tt>result.country</tt> - string -* <tt>result.country_code</tt> - string - -If you're familiar with the results returned by the geocoding service you're using you can access even more data, but you'll need to be familiar with the particular <tt>Geocoder::Result</tt> object you're using and the structure of your geocoding service's responses. (See below for links to geocoding service documentation.) - - -== Geocoding Services - -By default Geocoder uses Google's geocoding API to fetch coordinates and street addresses (FreeGeoIP is used for IP address info). However there are several other APIs supported, as well as a variety of settings. Please see the listing and comparison below for details on specific geocoding services (not all settings are supported by all services). Some common configuration options are: - - # config/initializers/geocoder.rb - Geocoder.configure do |config| - - # geocoding service (see below for supported options): - config.lookup = :yahoo - - # to use an API key: - config.api_key = "..." - - # geocoding service request timeout, in seconds (default 3): - config.timeout = 5 - - # set default units to kilometers: - config.units = :km - - # caching (see below for details): - config.cache = Redis.new - config.cache_prefix = "..." - - end - -Please see lib/geocoder/configuration.rb for a complete list of configuration options. Additionally, some lookups have their own configuration options which are listed in the comparison chart below, and as of version 1.2.0 you can pass arbitrary parameters to any geocoding service. For example, to use Nominatim's <tt>countrycodes</tt> parameter: - - Geocoder::Configuration.lookup = :nominatim - Geocoder.search("Paris", :params => {:countrycodes => "gb,de,fr,es,us"}) - - -=== Listing and Comparison - -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 (<tt>:google</tt>) - -API key:: required for Premier (do NOT use a key for the free version) -Key signup:: http://code.google.com/apis/maps/signup.html -Quota:: 2,500 requests/day, 100,000 with Google Maps API Premier -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) -Extra options:: <tt>:bounds</tt> - pass SW and NE coordinates as an array of two arrays to bias results towards a viewport -Documentation:: http://code.google.com/apis/maps/documentation/geocoding/#JSON -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..." -Notes:: To use Google Premier set <tt>Geocoder::Configuration.lookup = :google_premier</tt> and <tt>Geocoder::Configuration.api_key = [key, client, channel]</tt>. - -==== Yahoo (<tt>:yahoo</tt>) - -API key:: optional in development (required for production apps) -Key signup:: https://developer.apps.yahoo.com/wsregapp -Quota:: 50,000 requests/day, more available by special arrangement -Region:: world -SSL support:: no -Languages:: ? -Documentation:: http://developer.yahoo.com/geo/placefinder/guide/responses.html -Terms of Service:: http://info.yahoo.com/legal/us/yahoo/maps/mapsapi/mapsapi-2141.html -Limitations:: "YOU SHALL NOT... (viii) store or allow end users to store map imagery, map data or geocoded location information from the Yahoo! Maps APIs for any future use; (ix) use the stand-alone geocoder for any use other than displaying Yahoo! Maps or displaying points on Yahoo! Maps;" - -==== Bing (<tt>:bing</tt>) - -API key:: required -Key signup:: http://www.bingmapsportal.com -Quota:: 50,000 requests/24 hrs -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 (<tt>:nominatim</tt>) - -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. Data licensed under CC-BY-SA (you must provide attribution). - -==== Yandex (<tt>:yandex</tt>) - -API key:: none -Quota:: 25000 requests / day -Region:: world -SSL support:: no -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 (<tt>:geocoder_ca</tt>) - -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." - -==== Mapquest (<tt>:mapquest</tt>) - -API key:: none -Quota:: ? -Region:: world -SSL support:: no -Languages:: English -Documentation:: http://www.mapquestapi.com/geocoding/ -Terms of Service:: http://info.mapquest.com/terms-of-use/ -Limitations:: ? - -==== FreeGeoIP (<tt>:freegeoip</tt>) - -API key:: none -Quota:: 1000 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.rst -Terms of Service:: ? -Limitations:: ? - - -== Caching - -It's a good idea, when relying on any external service, 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::Configuration.cache = Redis.new - -This example uses Redis, but the cache store can be any object that supports these methods: - -* <tt>store#[](key)</tt> - retrieves a value -* <tt>store#[]=(key, value)</tt> - stores a value -* <tt>store#keys</tt> - lists all keys -* <tt>store#del(url)</tt> - deletes a value - -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::Configuration.cache_prefix = "..." - -By default the prefix is <tt>geocoder:</tt> - -If you need to expire cached content: - - Geocoder.cache.expire("http://...") # expire cached result for a URL - Geocoder.cache.expire(:all) # expire all cached results - -Do *not* include the prefix when passing a URL to be expired. Expiring <tt>:all</tt> will only expire keys with the configured prefix (won't kill every entry in your key/value store). - -<i>Before you implement caching in your app please be sure that doing so does not violate the Terms of Service for your geocoding service.</i> - - -== Forward and Reverse Geocoding in the Same Model - -If you apply both forward and reverse geocoding functionality to the same model (say 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 - -The reason for this is that we don't want ambiguity when doing distance calculations. We need a single, authoritative source for coordinates! - - -== Use Outside of Rails - -You can use Geocoder outside of Rails by calling the <tt>Geocoder.search</tt> method: - - results = Geocoder.search("McCarren Park, Brooklyn, NY") - -This returns an array of <tt>Geocoder::Result</tt> objects with all information provided by the geocoding service. Please see above and in the code for details. - - -== Testing Apps that Use Geocoder - -When writing tests for an app that uses Geocoder it may be useful to avoid network calls and have Geocoder return consistent, configurable results. To do this, configure and use the <tt>:test</tt> lookup. For example: - - Geocoder::Configuration.lookup = :test - - Geocoder::Lookup::Test.add_stub( - "New York, NY", [ - { - 'latitude' => 40.7143528, - 'longitude' => -74.0059731, - 'address' => 'New York, NY, USA', - 'state' => 'New York', - 'state_code' => 'NY', - 'country' => 'United States', - 'country_code' => 'US' - } - ] - ) - -Now, any time Geocoder looks up "New York, NY" its results array will contain one result with the above attributes. - - -== Command Line Interface - -When you install the Geocoder gem it adds a +geocode+ command to your shell. You can search for a street address, IP address, postal code, coordinates, etc just like you can with the Geocoder.search method for example: - - $ geocode 29.951,-90.081 - Latitude: 29.952211 - Longitude: -90.080563 - Full address: 1500 Sugar Bowl Dr, New Orleans, LA 70112, USA - City: New Orleans - State/province: Louisiana - Postal code: 70112 - Country: United States - Google map: http://maps.google.com/maps?q=29.952211,-90.080563 - -There are also a number of options for setting the geocoding API, key, and language, viewing the raw JSON reponse, and more. Please run <tt>geocode -h</tt> for details. - - -== Notes on MongoDB - -=== The Near Method - -Mongo document classes (Mongoid and MongoMapper) have a built-in +near+ scope, but since it only works two-dimensions Geocoder overrides it with its own spherical +near+ method in geocoded classes. - -=== Latitude/Longitude Order - -Coordinates are generally printed and spoken as latitude, then longitude ([lat,lon]). Geocoder respects this convention and always expects method arguments to be given in [lat,lon] order. However, MongoDB requires that coordinates be stored in [lon,lat] order as per the GeoJSON spec (http://geojson.org/geojson-spec.html#positions), so internally they are stored "backwards." However, this does not affect order of arguments to methods when using Mongoid or MongoMapper. - -To access an object's coordinates in the conventional order, use the <tt>to_coordinates</tt> instance method provided by Geocoder. For example: - - obj.to_coordinates # => [37.7941013, -122.3951096] # [lat, lon] - -Calling <tt>obj.coordinates</tt> directly returns the internal representation of the coordinates which, in the case of MongoDB, is probably the reverse of what you want: - - obj.coordinates # => [-122.3951096, 37.7941013] # [lon, lat] - -For consistency with the rest of Geocoder, always use the <tt>to_coordinates</tt> method instead. - - -== Distance Queries in SQLite - -SQLite's lack of trigonometric functions requires an alternate implementation of the +near+ scope. When using SQLite, Geocoder will automatically use a less accurate algorithm for finding objects near a given point. Results of this algorithm should not be trusted too much as it will return objects that are outside the given radius, along with inaccurate distance and bearing calculations. - - -=== Discussion - -There are few options for finding objects near a given point in SQLite without installing extensions: - -1. Use a square instead of a circle for finding nearby points. For example, if you want to find points near 40.71, 100.23, search for objects with latitude between 39.71 and 41.71 and longitude between 99.23 and 101.23. One degree of latitude or longitude is at most 69 miles so divide your radius (in miles) by 69.0 to get the amount to add and subtract from your center coordinates to get the upper and lower bounds. The results will not be very accurate (you'll get points outside the desired radius), but you will get all the points within the required radius. - -2. Load all objects into memory and compute distances between them using the <tt>Geocoder::Calculations.distance_between</tt> method. This will produce accurate results but will be very slow (and use a lot of memory) if you have a lot of objects in your database. - -3. If you have a large number of objects (so you can't use approach #2) and you need accurate results (better than approach #1 will give), you can use a combination of the two. Get all the objects within a square around your center point, and then eliminate the ones that are too far away using <tt>Geocoder::Calculations.distance_between</tt>. - -Because Geocoder needs to provide this functionality as a scope, we must go with option #1, but feel free to implement #2 or #3 if you need more accuracy. - - -== Tests - -Geocoder comes with a test suite (just run <tt>rake test</tt>) that mocks ActiveRecord and is focused on testing the aspects of Geocoder that do not involve executing database queries. Geocoder uses many database engine-specific queries which must be tested against all supported databases (SQLite, MySQL, etc). Ideally this involves creating a full, working Rails application, and that seems beyond the scope of the included test suite. As such, I have created a separate repository which includes a full-blown Rails application and some utilities for easily running tests against multiple environments: - -http://github.com/alexreisner/geocoder_test - - -== Error Handling - -By default Geocoder will rescue any exceptions raised by calls to the geocoding service and return an empty array (using warn() to inform you of the error). You can override this and implement custom error handling for certain exceptions by using the <tt>:always_raise</tt> option: - - Geocoder::Configuration.always_raise = [SocketError, TimeoutError] - -You can also do this to raise all exceptions: - - Geocoder::Configuration.always_raise = :all - -See <tt>lib/geocoder/exceptions.rb</tt> for a list of raise-able exceptions. - - -== Known Issue - -You cannot use the +near+ scope with another scope that provides an +includes+ option because the +SELECT+ clause generated by +near+ will overwrite it (or vice versa). Instead, try using +joins+ and pass a <tt>:select</tt> option to the +near+ scope to get the columns you want. For example: - - # instead of City.near(...).includes(:venues) - City.near("Omaha, NE", 20, :select => "cities.*, venues.*").joins(:venues) - -If anyone has a more elegant solution to this problem I am very interested in seeing it. - - -Copyright (c) 2009-12 Alex Reisner, released under the MIT license diff --git a/examples/autoexpire_cache.rb b/examples/autoexpire_cache.rb new file mode 100644 index 0000000000000000000000000000000000000000..cace891197f6d237080b3734956cac5a27cd13ee --- /dev/null +++ b/examples/autoexpire_cache.rb @@ -0,0 +1,30 @@ +# This class implements a cache with simple delegation to the Redis store, but +# when it creates a key/value pair, it also sends an EXPIRE command with a TTL. +# It should be fairly simple to do the same thing with Memcached. +class AutoexpireCache + def initialize(store) + @store = store + @ttl = 86400 + end + + def [](url) + @store.[](url) + end + + def []=(url, value) + @store.[]=(url, value) + @store.expire(url, @ttl) + end + + def keys + @store.keys + end + + def del(url) + @store.del(url) + end +end + +Geocoder.configure do |config| + config.cache = AutoexpireCache.new(Redis.new) +end diff --git a/lib/geocoder/calculations.rb b/lib/geocoder/calculations.rb index a3f1ff987c66dc5ae78bdf34eb6b940bf7edbc8d..9756d035f60ce765074ad9319f38fb204c957fb9 100644 --- a/lib/geocoder/calculations.rb +++ b/lib/geocoder/calculations.rb @@ -184,7 +184,7 @@ module Geocoder end ## - # Returns coordinates of the lower-left and upper-right corners of a box + # Returns coordinates of the southwest and northeast corners of a box # with the given point at its center. The radius is the shortest distance # from the center point to any side of the box (the length of each side # is twice the radius). diff --git a/lib/geocoder/lookups/freegeoip.rb b/lib/geocoder/lookups/freegeoip.rb index a3f6dc91a6662cf40ccc0a37a2461f822975ab0c..621d8ed638699b05bb695c370f8130cf22660151 100644 --- a/lib/geocoder/lookups/freegeoip.rb +++ b/lib/geocoder/lookups/freegeoip.rb @@ -12,7 +12,7 @@ module Geocoder::Lookup def results(query) # don't look up a loopback address, just return the stored result - return [reserved_result(query)] if query.loopback_ip_address? + return [reserved_result(query.text)] if query.loopback_ip_address? begin return (doc = fetch_data(query)) ? [doc] : [] rescue StandardError => err # Freegeoip.net returns HTML on bad request diff --git a/lib/geocoder/sql.rb b/lib/geocoder/sql.rb new file mode 100644 index 0000000000000000000000000000000000000000..69c146a9e2122419a4e513958df732db07edea1a --- /dev/null +++ b/lib/geocoder/sql.rb @@ -0,0 +1,104 @@ +module Geocoder + module Sql + extend self + + ## + # Distance calculation for use with a database that supports POWER(), + # SQRT(), PI(), and trigonometric functions SIN(), COS(), ASIN(), + # ATAN2(), DEGREES(), and RADIANS(). + # + # Based on the excellent tutorial at: + # http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL + # + def full_distance(latitude, longitude, lat_attr, lon_attr, options = {}) + earth = Geocoder::Calculations.earth_radius(options[:units] || :mi) + + "#{earth} * 2 * ASIN(SQRT(" + + "POWER(SIN((#{latitude} - #{lat_attr}) * PI() / 180 / 2), 2) + " + + "COS(#{latitude} * PI() / 180) * COS(#{lat_attr} * PI() / 180) * " + + "POWER(SIN((#{longitude} - #{lon_attr}) * PI() / 180 / 2), 2)" + + "))" + end + + ## + # Distance calculation for use with a database without trigonometric + # functions, like SQLite. Approach is to find objects within a square + # rather than a circle, so results are very approximate (will include + # objects outside the given radius). + # + # Distance and bearing calculations are *extremely inaccurate*. To be + # clear: this only exists to provide interface consistency. Results + # are not intended for use in production! + # + def approx_distance(latitude, longitude, lat_attr, lon_attr, options = {}) + dx = Geocoder::Calculations.longitude_degree_distance(30, options[:units] || :mi) + dy = Geocoder::Calculations.latitude_degree_distance(options[:units] || :mi) + + # sin of 45 degrees = average x or y component of vector + factor = Math.sin(Math::PI / 4) + + "(#{dy} * ABS(#{lat_attr} - #{latitude}) * #{factor}) + " + + "(#{dx} * ABS(#{lon_attr} - #{longitude}) * #{factor})" + end + + def within_bounding_box(sw_lat, sw_lng, ne_lat, ne_lng, lat_attr, lon_attr) + spans = "#{lat_attr} BETWEEN #{sw_lat} AND #{ne_lat} AND " + # handle box that spans 180 longitude + if sw_lng.to_f > ne_lng.to_f + spans + "#{lon_attr} BETWEEN #{sw_lng} AND 180 OR " + + "#{lon_attr} BETWEEN -180 AND #{ne_lng}" + else + spans + "#{lon_attr} BETWEEN #{sw_lng} AND #{ne_lng}" + end + end + + ## + # Fairly accurate bearing calculation. Takes a latitude, longitude, + # and an options hash which must include a :bearing value + # (:linear or :spherical). + # + # Based on: + # http://www.beginningspatial.com/calculating_bearing_one_point_another + # + def full_bearing(latitude, longitude, lat_attr, lon_attr, options = {}) + case options[:bearing] + when :linear + "CAST(" + + "DEGREES(ATAN2( " + + "RADIANS(#{lon_attr} - #{longitude}), " + + "RADIANS(#{lat_attr} - #{latitude})" + + ")) + 360 " + + "AS decimal) % 360" + when :spherical + "CAST(" + + "DEGREES(ATAN2( " + + "SIN(RADIANS(#{lon_attr} - #{longitude})) * " + + "COS(RADIANS(#{lat_attr})), (" + + "COS(RADIANS(#{latitude})) * SIN(RADIANS(#{lat_attr}))" + + ") - (" + + "SIN(RADIANS(#{latitude})) * COS(RADIANS(#{lat_attr})) * " + + "COS(RADIANS(#{lon_attr} - #{longitude}))" + + ")" + + ")) + 360 " + + "AS decimal) % 360" + end + end + + ## + # Totally lame bearing calculation. Basically useless except that it + # returns *something* in databases without trig functions. + # + def approx_bearing(latitude, longitude, lat_attr, lon_attr, options = {}) + "CASE " + + "WHEN (#{lat_attr} >= #{latitude} AND " + + "#{lon_attr} >= #{longitude}) THEN 45.0 " + + "WHEN (#{lat_attr} < #{latitude} AND " + + "#{lon_attr} >= #{longitude}) THEN 135.0 " + + "WHEN (#{lat_attr} < #{latitude} AND " + + "#{lon_attr} < #{longitude}) THEN 225.0 " + + "WHEN (#{lat_attr} >= #{latitude} AND " + + "#{lon_attr} < #{longitude}) THEN 315.0 " + + "END" + end + end +end diff --git a/lib/geocoder/stores/active_record.rb b/lib/geocoder/stores/active_record.rb index 34a52a787f90f5e5d253ff3c7c9909d7ac837869..4d4acfd26d036e664dc8a6b004bfea0b2727cb30 100644 --- a/lib/geocoder/stores/active_record.rb +++ b/lib/geocoder/stores/active_record.rb @@ -1,3 +1,4 @@ +require 'geocoder/sql' require 'geocoder/stores/base' ## @@ -36,11 +37,13 @@ module Geocoder::Store if Geocoder::Calculations.coordinates_present?(latitude, longitude) near_scope_options(latitude, longitude, *args) else - where(false_condition) # no results if no lat/lon given + # If no lat/lon given we don't want any results, but we still + # need distance and bearing columns so you can add, for example: + # .order("distance") + select(select_clause(nil, "NULL", "NULL")).where(false_condition) end } - ## # Find all objects within the area of a given bounding box. # Bounds must be an array of locations specifying the southwest @@ -49,14 +52,15 @@ module Geocoder::Store # scope :within_bounding_box, lambda{ |bounds| sw_lat, sw_lng, ne_lat, ne_lng = bounds.flatten if bounds - return where(false_condition) unless sw_lat && sw_lng && ne_lat && ne_lng - spans = "#{geocoder_options[:latitude]} BETWEEN #{sw_lat} AND #{ne_lat} AND " - spans << if sw_lng > ne_lng # Handle a box that spans 180 - "#{geocoder_options[:longitude]} BETWEEN #{sw_lng} AND 180 OR #{geocoder_options[:longitude]} BETWEEN -180 AND #{ne_lng}" + if sw_lat && sw_lng && ne_lat && ne_lng + {:conditions => Geocoder::Sql.within_bounding_box( + sw_lat, sw_lng, ne_lat, ne_lng, + full_column_name(geocoder_options[:latitude]), + full_column_name(geocoder_options[:longitude]) + )} else - "#{geocoder_options[:longitude]} BETWEEN #{sw_lng} AND #{ne_lng}" + select(select_clause(nil, "NULL", "NULL")).where(false_condition) end - { :conditions => spans } } end end @@ -69,7 +73,7 @@ module Geocoder::Store def distance_from_sql(location, *args) latitude, longitude = Geocoder::Calculations.extract_coordinates(location) if Geocoder::Calculations.coordinates_present?(latitude, longitude) - distance_from_sql_options(latitude, longitude, *args) + distance_sql(latitude, longitude, *args) end end @@ -94,141 +98,65 @@ module Geocoder::Store # * +:exclude+ - an object to exclude (used by the +nearbys+ method) # def near_scope_options(latitude, longitude, radius = 20, options = {}) + options[:units] ||= (geocoder_options[:units] || Geocoder::Configuration.units) + bearing = bearing_sql(latitude, longitude, options) + distance = distance_sql(latitude, longitude, options) if using_sqlite? - approx_near_scope_options(latitude, longitude, radius, options) - else - full_near_scope_options(latitude, longitude, radius, options) - end - end - - def distance_from_sql_options(latitude, longitude, options = {}) - if using_sqlite? - approx_distance_from_sql(latitude, longitude, options) + b = Geocoder::Calculations.bounding_box([latitude, longitude], radius, options) + args = b + [ + full_column_name(geocoder_options[:latitude]), + full_column_name(geocoder_options[:longitude]) + ] + conditions = Geocoder::Sql.within_bounding_box(*args) else - full_distance_from_sql(latitude, longitude, options) + conditions = ["#{distance} <= ?", radius] end + { + :select => select_clause(options[:select], distance, bearing), + :conditions => add_exclude_condition(conditions, options[:exclude]), + :order => options.include?(:order) ? options[:order] : "distance ASC" + } end ## - # Scope options hash for use with a database that supports POWER(), - # SQRT(), PI(), and trigonometric functions SIN(), COS(), ASIN(), - # ATAN2(), DEGREES(), and RADIANS(). + # SQL for calculating distance based on the current database's + # capabilities (trig functions?). # - # Bearing calculation based on: - # http://www.beginningspatial.com/calculating_bearing_one_point_another - # - def full_near_scope_options(latitude, longitude, radius, options) - lat_attr = geocoder_options[:latitude] - lon_attr = geocoder_options[:longitude] - options[:bearing] ||= (options[:method] || - geocoder_options[:method] || - Geocoder::Configuration.distances) - bearing = case options[:bearing] - when :linear - "CAST(" + - "DEGREES(ATAN2( " + - "RADIANS(#{full_column_name(lon_attr)} - #{longitude}), " + - "RADIANS(#{full_column_name(lat_attr)} - #{latitude})" + - ")) + 360 " + - "AS decimal) % 360" - when :spherical - "CAST(" + - "DEGREES(ATAN2( " + - "SIN(RADIANS(#{full_column_name(lon_attr)} - #{longitude})) * " + - "COS(RADIANS(#{full_column_name(lat_attr)})), (" + - "COS(RADIANS(#{latitude})) * SIN(RADIANS(#{full_column_name(lat_attr)}))" + - ") - (" + - "SIN(RADIANS(#{latitude})) * COS(RADIANS(#{full_column_name(lat_attr)})) * " + - "COS(RADIANS(#{full_column_name(lon_attr)} - #{longitude}))" + - ")" + - ")) + 360 " + - "AS decimal) % 360" - end - options[:units] ||= (geocoder_options[:units] || Geocoder::Configuration.units) - distance = full_distance_from_sql(latitude, longitude, options) - conditions = ["#{distance} <= ?", radius] - default_near_scope_options(latitude, longitude, radius, options).merge( - :select => select_clause(options[:select], distance, bearing), - :conditions => add_exclude_condition(conditions, options[:exclude]) + def distance_sql(latitude, longitude, options = {}) + method_prefix = using_sqlite? ? "approx" : "full" + Geocoder::Sql.send( + method_prefix + "_distance", + latitude, longitude, + full_column_name(geocoder_options[:latitude]), + full_column_name(geocoder_options[:longitude]), + options ) end - - # Distance calculations based on the excellent tutorial at: - # http://www.scribd.com/doc/2569355/Geo-Distance-Search-with-MySQL - - def full_distance_from_sql(latitude, longitude, options) - lat_attr = geocoder_options[:latitude] - lon_attr = geocoder_options[:longitude] - - earth = Geocoder::Calculations.earth_radius(options[:units] || :mi) - - "#{earth} * 2 * ASIN(SQRT(" + - "POWER(SIN((#{latitude} - #{full_column_name(lat_attr)}) * PI() / 180 / 2), 2) + " + - "COS(#{latitude} * PI() / 180) * COS(#{full_column_name(lat_attr)} * PI() / 180) * " + - "POWER(SIN((#{longitude} - #{full_column_name(lon_attr)}) * PI() / 180 / 2), 2) ))" - end - - def approx_distance_from_sql(latitude, longitude, options) - lat_attr = geocoder_options[:latitude] - lon_attr = geocoder_options[:longitude] - - dx = Geocoder::Calculations.longitude_degree_distance(30, options[:units] || :mi) - dy = Geocoder::Calculations.latitude_degree_distance(options[:units] || :mi) - - # sin of 45 degrees = average x or y component of vector - factor = Math.sin(Math::PI / 4) - - "(#{dy} * ABS(#{full_column_name(lat_attr)} - #{latitude}) * #{factor}) + " + - "(#{dx} * ABS(#{full_column_name(lon_attr)} - #{longitude}) * #{factor})" - end - ## - # Scope options hash for use with a database without trigonometric - # functions, like SQLite. Approach is to find objects within a square - # rather than a circle, so results are very approximate (will include - # objects outside the given radius). - # - # Distance and bearing calculations are *extremely inaccurate*. They - # only exist for interface consistency--not intended for production! + # SQL for calculating bearing based on the current database's + # capabilities (trig functions?). # - def approx_near_scope_options(latitude, longitude, radius, options) - lat_attr = geocoder_options[:latitude] - lon_attr = geocoder_options[:longitude] - unless options.include?(:bearing) - options[:bearing] = (options[:method] || \ - geocoder_options[:method] || \ - Geocoder::Configuration.distances) + def bearing_sql(latitude, longitude, options = {}) + if !options.include?(:bearing) + options[:bearing] = Geocoder::Configuration.distances end if options[:bearing] - bearing = "CASE " + - "WHEN (#{full_column_name(lat_attr)} >= #{latitude} AND #{full_column_name(lon_attr)} >= #{longitude}) THEN 45.0 " + - "WHEN (#{full_column_name(lat_attr)} < #{latitude} AND #{full_column_name(lon_attr)} >= #{longitude}) THEN 135.0 " + - "WHEN (#{full_column_name(lat_attr)} < #{latitude} AND #{full_column_name(lon_attr)} < #{longitude}) THEN 225.0 " + - "WHEN (#{full_column_name(lat_attr)} >= #{latitude} AND #{full_column_name(lon_attr)} < #{longitude}) THEN 315.0 " + - "END" - else - bearing = false + method_prefix = using_sqlite? ? "approx" : "full" + Geocoder::Sql.send( + method_prefix + "_bearing", + latitude, longitude, + full_column_name(geocoder_options[:latitude]), + full_column_name(geocoder_options[:longitude]), + options + ) end - - options[:units] ||= (geocoder_options[:units] || Geocoder::Configuration.units) - distance = approx_distance_from_sql(latitude, longitude, options) - - b = Geocoder::Calculations.bounding_box([latitude, longitude], radius, options) - conditions = [ - "#{full_column_name(lat_attr)} BETWEEN ? AND ? AND #{full_column_name(lon_attr)} BETWEEN ? AND ?"] + - [b[0], b[2], b[1], b[3] - ] - default_near_scope_options(latitude, longitude, radius, options).merge( - :select => select_clause(options[:select], distance, bearing), - :conditions => add_exclude_condition(conditions, options[:exclude]) - ) end ## # Generate the SELECT clause. # - def select_clause(columns, distance, bearing) + def select_clause(columns, distance, bearing = nil) if columns == :geo_only clause = "" else @@ -238,22 +166,12 @@ module Geocoder::Store (bearing ? ", #{bearing} AS bearing" : "") end - ## - # Options used for any near-like scope. - # - def default_near_scope_options(latitude, longitude, radius, options) - { - :order => options[:order] || "distance", - :limit => options[:limit], - :offset => options[:offset] - } - end - ## # Adds a condition to exclude a given object by ID. - # The given conditions MUST be an array. + # Expects conditions as an array or string. Returns array. # def add_exclude_condition(conditions, exclude) + conditions = [conditions] if conditions.is_a?(String) if exclude conditions[0] << " AND #{full_column_name(primary_key)} != ?" conditions << exclude.id @@ -289,8 +207,8 @@ module Geocoder::Store do_lookup(false) do |o,rs| if r = rs.first unless r.latitude.nil? or r.longitude.nil? - o.send :write_attribute, self.class.geocoder_options[:latitude], r.latitude - o.send :write_attribute, self.class.geocoder_options[:longitude], r.longitude + o.__send__ "#{self.class.geocoder_options[:latitude]}=", r.latitude + o.__send__ "#{self.class.geocoder_options[:longitude]}=", r.longitude end r.coordinates end @@ -307,7 +225,7 @@ module Geocoder::Store do_lookup(true) do |o,rs| if r = rs.first unless r.address.nil? - o.send :write_attribute, self.class.geocoder_options[:fetched_address], r.address + o.__send__ "#{self.class.geocoder_options[:fetched_address]}=", r.address end r.address end