* DEPRECATION: Geocoder.search now returns an array instead of a single result.
* DEPRECATION: obj.nearbys second argument is now an options hash (instead of units). Please change <tt>obj.nearbys(20, :km)</tt> to: <tt>obj.nearbys(20, :units => :km)</tt>.
@@ -9,6 +9,8 @@ Geocoder has been successfully tested with Ruby (MRI) 1.8.7, 1.9.2, and JRuby 1.
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@@ -9,6 +9,8 @@ Geocoder has been successfully tested with Ruby (MRI) 1.8.7, 1.9.2, and JRuby 1.
Geocoder is compatible with Rails 3. If you need to use it with Rails 2 please see the <tt>rails2</tt> branch (no longer maintained, limited feature set).
Geocoder is compatible with Rails 3. If you need to use it with Rails 2 please see the <tt>rails2</tt> branch (no longer maintained, limited feature set).
Geocoder also works outside of Rails but you'll need to install either the +json+ (for MRI) or +json_pure+ (for JRuby) gem.
== Install
== Install
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@@ -33,13 +35,22 @@ At the command prompt:
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@@ -33,13 +35,22 @@ At the command prompt:
=== Required Attributes
=== Required Attributes
Your object 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):
*ActiveRecord:* Your object 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):
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+).
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+).
*Mongoid:* Define your address and coordinate fields right in the model. You also need to include the <tt>Geocoder::Model::Mongoid</tt> module _before_ calling <tt>geocoded_by</tt>:
field :address
field :latitude, :type => Float
field :longitude, :type => Float
include Geocoder::Model::Mongoid
geocoded_by :address
=== Model Behavior
=== Model Behavior
In your model, tell Geocoder which method returns your object's full address:
In your model, tell Geocoder which method returns your object's full address:
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@@ -82,12 +93,37 @@ Some utility methods are also available:
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@@ -82,12 +93,37 @@ Some utility methods are also available:
=> 3619.77359999382
=> 3619.77359999382
# find the geographic center (aka center of gravity) of objects or points
# find the geographic center (aka center of gravity) of objects or points
<i>Note: when using SQLite +distance+ and +bearing+ values are provided for interface consistency only. They are not accurate.</i>
== More on Configuration
== More on Configuration
You are not stuck with using the +latitude+ and +longitude+ database column names for storing coordinates. For example, to use +lat+ and +lon+:
You are not stuck with using the +latitude+ and +longitude+ database column names for storing coordinates. For example, to use +lat+ and +lon+:
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@@ -126,14 +162,14 @@ So far we have looked at shortcuts for assigning geocoding results to object att
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@@ -126,14 +162,14 @@ So far we have looked at shortcuts for assigning geocoding results to object att
Every <tt>Geocoder::Result</tt> object, +result+, provides the following data:
Every <tt>Geocoder::Result</tt> object, +result+, provides the following data:
* <tt>result.latitude # float</tt>
* +result.latitude+ - float
* <tt>result.longitude # float</tt>
* +result.longitude+ - float
* <tt>result.coordinates # array of the above two</tt>
* +result.coordinates+ - array of the above two
* <tt>result.address # string</tt>
* +result.address+ - string
* <tt>result.city # string</tt>
* +result.city+ - string
* <tt>result.postal_code # string</tt>
* +result.postal_code+ - string
* <tt>result.country_name # string</tt>
* +result.country_name+ - string
* <tt>result.country_code # string</tt>
* +result.country_code+ - string
and if you're familiar with the results returned by the geocoding service you're using, you can access even more (see code comments for details: <tt>lib/geocoder/results/*</tt>).
and if you're familiar with the results returned by the geocoding service you're using, you can access even more (see code comments for details: <tt>lib/geocoder/results/*</tt>).
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@@ -144,34 +180,81 @@ By default Geocoder uses Google's geocoding API to fetch coordinates and address
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@@ -144,34 +180,81 @@ By default Geocoder uses Google's geocoding API to fetch coordinates and address
# config/initializers/geocoder.rb
# config/initializers/geocoder.rb
Geocoder::Configuration.lookup = :yahoo
Geocoder::Configuration.lookup = :yahoo
Geocoder::Configuration.yahoo_appid = "..."
To obtain a Yahoo app id go to:
Street address geocoding services currently supported (valid settings for the above):
https://developer.apps.yahoo.com/wsregapp
* Google: <tt>:google</tt>
* Yahoo: <tt>:yahoo</tt>
* Geocoder.ca: <tt>:geocoder_ca</tt> (US and Canada only)
Note that the result objects returned by different geocoding services all implement the methods listed above. Beyond that, however, you must be familiar with your particular subclass of <tt>Geocoder::Result</tt> and the geocoding service's result structure:
Note that the result objects returned by different geocoding services all implement the methods listed above. Beyond that, however, you must be familiar with your particular subclass of <tt>Geocoder::Result</tt> and the geocoding service's result structure:
You can set the timeout used for connections to the geocoding service. The default is 3 seconds but if you want to set it to 5, for example, put the following in an initializer:
You can set the timeout used for connections to the geocoding service. The default is 3 seconds but if you want to set it to 5, for example, put the following in an initializer:
# config/initializers/geocoder.rb
Geocoder::Configuration.timeout = 5
Geocoder::Configuration.timeout = 5
=== Language
=== Language
You can set the language used for reverse geocoding results to German, for example, by setting the following:
You can set the language used for reverse geocoding results to German, for example, by setting the following:
# config/initializers/geocoder.rb
Geocoder::Configuration.language = :de
Geocoder::Configuration.language = :de
For a list of supported languages see the documentation for the geocoding service you're using.
For a list of supported languages see the documentation for the geocoding service you're using.
=== HTTPS
If you want to use HTTPS for geocoding service connections:
Geocoder::Configuration.use_https = true
Note that currently the only service that supports HTTPS is Google.
== Caching Results
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
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).
== Forward and Reverse Geocoding in the Same Model
== Forward and Reverse Geocoding in the Same Model
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@@ -217,23 +300,21 @@ Geocoder adds a +location+ method to the standard <tt>Rack::Request</tt> object
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@@ -217,23 +300,21 @@ Geocoder adds a +location+ method to the standard <tt>Rack::Request</tt> object
You can use Geocoder outside of Rails by calling the <tt>Geocoder.search</tt> method:
You can use Geocoder outside of Rails by calling the <tt>Geocoder.search</tt> method:
result = Geocoder.search("McCarren Park, Brooklyn, NY")
results = Geocoder.search("McCarren Park, Brooklyn, NY")
This returns a <tt>Geocoder::Result</tt> object with all information provided by the geocoding service. Please see above and in the code for details.
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.
== Distance Queries in SQLite
== 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.
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.
It is also not possible to calculate distances between points without the trig functions so you cannot sort results by "nearness."
=== Discussion
=== Discussion
There are few options for finding objects near a given point in SQLite without installing extensions:
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--at worst 29% farther away), but you will get all the points within the required radius.
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.
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.
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@@ -252,12 +333,11 @@ You cannot use the +near+ scope with another scope that provides an +includes+ o
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@@ -252,12 +333,11 @@ You cannot use the +near+ scope with another scope that provides an +includes+ o
If anyone has a more elegant solution to this problem I am very interested in seeing it.
If anyone has a more elegant solution to this problem I am very interested in seeing it.
