A Geo extension for Mongoid.
- Supports Mongoid 1.7 sphere distance calculations and
- Adds nearSphere inclusion method
- Adds a set of geo related inflections
- Adds an exta option for defining a “geo” field, to have the generated attr_writer parse and convert strings etc. to float arrays.
Address.near(:latlng => [37.761523, -122.423575, 1])
base.where(:location.within => { "$center" => [ [ 50, -40 ], 1 ] })
class Person field :location, :type => Array index [[ :location, Mongo::GEO2D ]], :min => -180, :max => 180 end # to ensure indexes are created, either: Mongoid.autocreate_indexes = true # or in the mongoid.yml autocreate_indexes: true
These are the only geo features I could find are currently built-in for Mongoid 2.
Mongoid Geo implements the following extra features…
The following briefly demonstrates all the features that Mongoid Geo currently provides
Old/Manual way: index [[ :location, Mongo::GEO2D ]], :min => -180, :max => 180
Using new geo_index class method : geo_index :location
Note: For embedded documents, you must define the index in the root collection class. (davemitchell)
When setting a geo-location array, the setter should try to convert the value to an array of floats
Old/Manual way:
class Person field :locations, :type => Array def locations= args @locations = args.kind_of?(String) ? args.split(",").map(&:to_f) : args end end
With the new :geo
option supplied by mongoid-geo :
class Person field :location, :type => Array, :geo => true geo_index :location end p = Person.new # A Geo array can now be set via String or Strings, Hash or Object, here a few examples... # Please see geo_fields_spec.rb for more options! p.location = "45.1, -3.4" p.location = "45.1", "-3.4" p.location = {:lat => 45.1, :lng => -3.4} p.location = [{:lat => 45.1, :lng => -3.4}] p.location = {:latitude => 45.1, :longitude => -3.4} my_location = Location.new :latitude => 45.1, :longitude => -3.4 p.location = my_location # for each of the above, the following holds assert([45.1, -3.4], p.location) # also by default adds #lat and #lng convenience methods (thanks to TeuF) assert(45.1 , p.lat) assert(-3.4 , p.lng) # the #lat and #lng convenience methods can also be customized with the :lat and :lng options field :location, :type => Array, :geo => true, :lat => :latitude, :lng => :longitude assert(45.1 , p.latitude) assert(-3.4 , p.longitude) # or set the array attributes using symmetric setter convenience methods! p.latitude = 44 assert(44 , p.latitude) # PURE MAGIC!!!
- Added support for geoNear queries!!!
class Address include Mongoid::Document extend Mongoid::Geo::Near field :location, :type => Array, :geo => true ... end # Find all addresses sorted nearest to a specific address loation nearest_addresses = Address.geoNear(another_address, :location) class Position include Mongoid::Document field :pos, :type => Array, :geo => true ... end # Find all positions sorted nearest to the address loation nearest_positions = Position.geoNear(another_address.location, :pos) # perform distance locations in Speherical mode inside Mongo DB (default is :plane) nearest_positions = Position.geoNear(another_address.location, :pos, :mode => :sphere) # other options supported are: :num, :maxDistance, :distanceMultiplier, :query # GeoNear distance returns distance in degrees. Use distanceMultiplier to return in Miles or KM. # set distanceMultiplier to 6371 to get distance in KM # set distanceMultiplier to 3963.19 to get distance in Miles
If you need to operate on the Mongoid models referenced by the query result, simply call #to_models on it
Fx to get the city of the first model instance from the query result:
nearest_city = Position.geoNear(another_address.location, :pos).to_models.first.city
You can also use a #to_model method on an individual query result like this:
nearest_city = Position.geoNear(another_address.location, :pos).first.to_model.city
- the model returned also has a distance accessor populated with the distance calculated by running the geoNear query
nearest_distance = Position.geoNear(another_address.location, :pos).first.to_model.distance
You can now explicitly set/configure the Mongo DB version used. This will affect whether built-in Mongo DB distance calculation will be used or using standalone Ruby Haversine algorithm. By default the version is set to 1.5. See geo_near specs for more details/info on this.
Mongoid::Geo.mongo_db_version = 1.7
Find addresses near a point using spherical distance calculation
Address.nearSphere(:location => [ 72, -44 ])
base.where(:location.nearSphere => [ 72, -44 ]) # => :location => { "$nearSphere" : [ 72, -44 ] }
Find points near a given point within a maximum distance
base.where(:location.nearMax => [[ 72, -44 ], 5]) # => { $near: [50, 40] , $maxDistance: 3 } base.where(:location.nearMax(:sphere) => [[ 72, -44 ], 5]) # => { $nearSphere: [50, 40] , $maxDistanceSphere: 3 } base.where(:location.nearMax(:sphere, :flat) => [[ 72, -44 ], 5]) # => { $nearSphere: [50, 40] , $maxDistance: 3 }
You can also use a Hash to define the nearMax
places.where(:location.nearMax => {:point => [ 72, -44 ], :distance => 5})
Or use an Object (which must have the methods #point
and #distance
that return the point and max distance from that point)
near_max_ = (Struct.new :point, :distance).new near_max.point = [50, 40] near_max.distance = [30,55] places.where(:location.nearMax => near_max)
Note: For the points, you can also use a hash or an object with the methods/keys, either :lat, :lng
or :latitude, :longitude
Example:
center = (Struct.new :lat, :lng).new center.lat = 72 center.lng = -44 places.where(:location.withinCenter => [center, radius]) # OR places.where(:location.withinCenter => [{:lat => 72, :lng => -44}, radius])
box = [[50, 40], [30,55]] base.where(:location.withinBox => box) # => locations: {"$within" : {"$box" : [[50, 40], [30,55]]} base.where(:location.withinBox(:sphere) => box) # => locations: {"$within" : {"$boxSphere" : [[50, 40], [30,55]]}
You can also use a Hash to define the box
places.where(:location.withinBox => {:lower_left => [50, 40], :upper_right => [30,55]}) # or mix and match places.where(:location.withinBox => {:lower_left => {:lat => 50, :lng => 40}, :upper_right => [30,55] } )
Or use an object (which must have the methods #lower_left
and #upper_right
that return the points of the bounding box)
box = (Struct.new :lower_left, :upper_right).new box.lower_left = [50, 40] box.upper_right = [30, 55] places.where(:location.withinBox => box)
center = [50, 40] radius = 4 places.where(:location.withinCenter => [center, radius]) # => places: {"$within" : {"$center" : [[50, 40], 4]} places.where(:location.withinCenter(:sphere) => [center, radius]) # => places: {"$within" : {"$centerSphere" : [[50, 40], 4]}
You can also use a hash to define the circle, with :center
and :radius
keys
places.where(:location.withinCenter => {:center => [50, 40], :radius => 4})
Or use an object (which must have the methods #lower_left and #upper_right that return the points of the bounding box)
circle = (Struct.new :center, :radius).new circle.center = [50, 40] circle.radius = 4 places.where(:location.withinCenter => circle)