Rails 7.1: implementing Validating Presence of Associated Models Using Custom Validators
I'm experimenting with Hey everyone, I'm running into an issue that's driving me crazy. I tried several approaches but none seem to work... I'm experiencing unexpected behavior with custom validators in Rails 7.1 when trying to validate the presence of associated models. I have a `User` model that has many `Posts`, and I want to ensure that when a `User` is created, they must have at least one `Post`. I created a custom validator, but it seems to bypass the presence validation under certain conditions. Here's what I have: ```ruby class User < ApplicationRecord has_many :posts validate :must_have_at_least_one_post private def must_have_at_least_one_post errors.add(:base, "User must have at least one post") if posts.empty? end end ``` I attempted to create a user without any posts, expecting the validation to trigger. However, the user is still being created without any errors, and that’s not the behavior I anticipated. I have also checked that the `posts` association is correctly initialized, and it shows up as an empty array when I check `user.posts`. I thought maybe the scenario lies in the timing of validation. To debug, I added some logging in the `must_have_at_least_one_post` method, and it appears that the method is never called during the validation process. I've also tried calling `valid?` on the user instance directly after creating it, but it still returns true. I would appreciate any insights into what might be causing this scenario. Are there special considerations for custom validators that I might be overlooking? Also, is there a better approach to ensure that a user has at least one post upon creation? Thanks in advance for any help! This is part of a larger application I'm building. Any examples would be super helpful.