Executing custom validation before record created?

Question

I want to execute a custom validation before the record is created?

It looks as if this is the right method: before_validation_on_create. For example:

before_validation_on_create :custom_validation

But am not sure. Any help would be appreciated.

Answer 1

There's a great resource here for information on callbacks and the order they happen in:

http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html

Answer 2

before_validation_on_create hooks happen before validation on create… but they aren't validations themselves.

What you probably want to do is use validate and a private method which adds to the error array. like this:

class IceCreamCone

validate :ensure_ice_cream_is_not_melted, :before => :create

private
  def ensure_ice_cream_is_not_melted
    if self.ice_cream.melted?
      errors.add(:ice_cream, 'is melted.')
    end
  end
end