How to create an association in Rails?

Question

MongoDB

Hello, I'm using Ruby on Rails 5.2, Mongoid 7.0 and Geocoder
. I have a Place model where the user's location is created, I need it to be associated with another City model via field : city when creating a location (so that it is created new or added to an existing one, I understand that something like this should look like self.city = City.find_or_create_by(name: name) if name.present? ).
place.rb

class Place
  include Mongoid::Document
  include Mongoid::Timestamps
  include Geocoder::Model::Mongoid
  field :coordinates, type: Array
  field :latitude, type: Float
  field :longitude, type: Float

  field :city, type: String

  field :current_position, type: Boolean, default: "true"

  belongs_to :user, touch: true
  belongs_to :city, touch: true
 
  before_validation :initialize_coordinates
  after_validation :reverse_geocode

  def initialize_coordinates
    self.coordinates = [self.longitude.to_f, self.latitude.to_f]
  end

  reverse_geocoded_by :coordinates do |obj,results|
    if geo = results.first
      obj.city = geo.city || geo.state
    end
  end
end

city.rb

class City
  include Mongoid::Document
  include Mongoid::Timestamps

  field :name, type: String
  field :created_at, type: Time

  has_many :places
end

Answer 1

Isn't it easier to pass city_id from the form?