Codebeerstartups

Use belongs_to with presence validator

Introduction

user

Mohit Jain

Rails Developer


validations, associations

Use belongs_to with presence validator

Posted by Mohit Jain on .
Featured

validations, associations

Use belongs_to with presence validator

Posted by Mohit Jain on .

Assume we have two models: User and Image. User has one image and image belongs to user. The code below:

class User < ActiveRecord::Base
  has_one :image
end

class Image < ActiveRecord::Base
  belongs_to :user
end

Now we want to add validation for image to check if user is there or not.

class Image < ActiveRecord::Base
  belongs_to :user
  validates :user, :presence => true
end

So by adding just one line whenever you are trying to save image object, it will fire a query with respect to the user_id to check weather that user exists or not. In case user doesn’t exits “image.save” with return an error.

Happy Hacking :)

user

Mohit Jain

http://codebeerstartups.com

Rails Developer