ruby - How to reference an embedded document in Mongoid? -

using mongoid, let's have following classes:

class map   include mongoid::document    embeds_many :locations end  class location   include mongoid::document    field :x_coord, :type => integer   field :y_coord, :type => integer    embedded_in      :map, :inverse_of => :locations end   class player   include mongoid::document    references_one   :location end 

as can see, i'm trying model simple game world environment map embeds locations, , player references single location current spot.

using approach, i'm getting following error when try reference "location" attribute of player class:

mongoid::errors::documentnotfound: document not found class location id(s) xxxxxxxxxxxxxxxxxxx. 

my understanding because location document embedded making difficult reference outside scope of embedding document (the map). makes sense, how model direct reference embedded document?

because maps own collection, need iterate on every map collection searching within location player referenced.

you can't access embedded documents directly. have enter through collection , work way down.

to avoid iterating of maps can store both location reference , map reference in player document. allows chain criteria selects map , location within it. have code method on player class handle this.

def location   self.map.locations.find(self.location_id) end 

so, similar how answered except still store location_id in player document instead of using coord attribs.

another way put maps, locations, , players in own collections instead of embedding location in map collection. use reference relationships without doing fancy... using hierarchical database likes it's relational database @ point...