Question

I have an array of Mongo objects returned by a geolocation query such as :

@data = Record.geo_near([lng,lat], :max_distance => dist, :unit => :m, :spherical => true)

I’m then trying to serialize the response based on the expected format :

respond_to do |format|
    format.html 
    format.json { render json: @data, :status => 200 } # Not working
    format.xml { render xml: @data, :status => 200 } # Working !
end

The weird thing is that everything go smoothly with XML, but I get this error with JSON :

ActiveSupport::JSON::Encoding::CircularReferenceError in BouncesController#populars
object references itself

I found this post relating to the same kind of error, but the validated answer did not work for me.

Any ideas?

EDIT

Here is my model for which the issue is happening :

class MyModel
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Spacial::Document

  spacial_index :loc, :min => -180, :max => 180
  belongs_to :user

  field :text, :type => String
  field :loc, :type => Array, spacial: true
  field :accuracy, :type => Float

  def as_json(options={})
  {
  "id" => self.id,
  "text" => self.text,
  "loc" => self.loc,
  "accuracy" => self.accuracy,
  "user" => {
    "id" => self.user['_id'],
    "login" => self.user['login'],
    "role" => self.user['role']
  },
  "created_at" => self.created_at,
  "updated_at" => self.updated_at
  }
  end
end

Answer 1

For now I have resolved the issue by downgrading my gems as follow :

gem 'mongo', '1.4.0'
gem "mongoid", "~> 2.4"
gem "bson_ext", "~> 1.5"

There is still the possibility to use the following hack, but it prevents you to format yourself the json output in your model.

format.json { render json: Hash.from_xml(@data.to_xml).to_json, :status => 200 }