How to make a dependency inside a Rails model?

Question

Ruby on Rails

I use Ruby on Rails and Mongoid.
There is a Place model where users can mark their location and set current_position to true .
It is necessary that when the user creates a new location, when he sets current_positon true from his other locations, this value becomes false .

class Place
  include Mongoid::Document

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

  validates :user_id, presence: true

  belongs_to :user, touch: true
 
end

Answer 1

class Place
  include Mongoid::Document

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

  validates :user_id, presence: true

  belongs_to :user, touch: true

  after_save :update_position_for_other, if: :current_position_changed?

  private

  def update_position_for_other
    Place.where(:id.ne => id, user_id: user_id).update_all(current_position: false) if current_position
  end
end