👀 Views: 6941 💬 Answers: 1 📅 Created: 2025-06-06

ruby rails activemodel Ruby

I'm maintaining legacy code that I've been banging my head against this for hours... I can't seem to get I'm working with an scenario with custom validations in a Rails 7 application. I created a form object to handle a more complex submission involving multiple models, but the custom validation seems to be skipping over some conditions. Specifically, I have a validation that checks if a related model exists based on the input from the form object, but it always returns true, even when the related model doesn't exist. Here's the relevant code for my form object: ```ruby class MyForm include ActiveModel::Model attr_accessor :name, :related_model_id validates :name, presence: true validate :related_model_must_exist def related_model_must_exist return if related_model_id.blank? unless RelatedModel.exists?(id: related_model_id) errors.add(:related_model_id, 'must refer to an existing related model') end end end ``` In my controller, I instantiate the form object like this: ```ruby def create @form = MyForm.new(form_params) if @form.valid? # Proceed with creation logic else # Handle errors end end private def form_params params.require(:my_form).permit(:name, :related_model_id) end ``` When I submit the form with a valid name and an invalid `related_model_id`, I expect the validation to unexpected result and the behavior message to be added to `@form.errors`. However, it seems to pass validation every time. I've tried debugging by adding `puts` statements in the validation method to check the value of `related_model_id`, and it appears correct. Also, I checked if `RelatedModel.exists?` returns the expected results in the Rails console, which it does. I suspect there might be something related to how ActiveModel validations are processed in this context. Any insights on what I might be missing here? Could it be a potential conflict with how form objects handle validations or some other configuration that I'm overlooking? My development environment is Linux. Any ideas what could be causing this? What's the best practice here? Thanks for your help in advance! My development environment is Ubuntu 20.04. What are your experiences with this?