модель Layer

layer.rb

class Layer
  include Mongoid::Document
  include Mongoid::Timestamps

  #TODO create geotype filter
  field :geotypes, type: Array
  field :structure_json, type: String
  field :is_spatial, type: Boolean, default: true
  field :has_many_geoms, type: Boolean, default: false

  embeds_many :layers_objects

  before_validation :set_fields
  after_save :clear_temp_attributes

  attr_accessor :structure

  def structure
    if new_record?
      @structure ||= attributes["structure"]
    else
      t = {}
      JSON.parse(structure_json).each{|k,v| t[k.to_sym] = v.to_sym}
      @structure ||= t
    end
  end

  def new_layers_object attrs
    return if structure.blank?
    layers_object = self.layers_objects.new
    structure.each{|k,t|
      layers_object.fields_objects.new key: k, value: attrs[k], field_type: t
    }
    layers_object
  end

  private

  def set_fields
    self.structure_json = structure.to_json
  end

  def clear_temp_attributes
    @structure = nil
  end

end