CODEWITHSUNDEEP
ruby-on-railsvalidationmodel
Kristiyan Tsvetanov
Kristiyan Tsvetanov

Reputation: 1047

Rails, validate existance of object from other model

I have a simple app with 3 models - Restaurant, Employee, and User. My Restaurant model has_many employees and I can hire other employees by creating them and giving a value to an attribute user_id of the employee. How to check for the presence of User with id=user_id before saving the new employee? Thank you!

EDIT======= The solution

validate :user_exists

  def user_exists
   if User.exists?(self.user_id)
    return true
   else
    self.errors.add(:user_id, "Unable to find this user.")
    return false
   end
  end

Upvotes: 0

Views: 626

Answers (3)

Anthony E
Anthony E

Reputation: 11235

There's actually a simpler way of doing this since you can validate the belongs_to the association directly:

In Employee:

validates :user, presence: true, message: "could not be found"

Upvotes: 2

Kristiyan Tsvetanov
Kristiyan Tsvetanov

Reputation: 1047

It works with this code(No employee is created when the id is not found) but the error message is not showing... 

     validate :user_exists

      def user_exists
       if User.exists?(self.user_id)
        return true
       else
        self.errors.add(:error, "Unable to find this user.")
        return false
       end
      end

Upvotes: 0

Shani
Shani

Reputation: 2541

class Employee < ActiveRecord::Base

  validate :user_exists, message: "#{user_id} must be a valid user"

  def user_exists
   return false if User.find(self.user_id).nil?
  end
end

Upvotes: 1

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