How to call a Rails method before a validations occur

If you need some behavior to occur before validations take place on an ActiveRecord object, you can add the before_validation callback to your ActiveRecord model. This method accepts a method name as an argument which will be automatically invoked before validations are run.

You will also have access to the ActiveRecord within the invoked callback method, it can be referenced explicitly through self. Or you can just call its attribute methods directly because self is the default object.

class Account < ApplicationRecord
  # is called second
  validates_presence_of :name, :email
  # is called first
  before_validation :clean_record

  def clean_record
    p "#{self.inspect}"
    p "#{name}"

Accout.create(name: "blue bacon", email: "blue@bacon.istasty")
# Puts output from clean_record invocation:
# "#<Account id: nil, name: \"blue bacon\", email: \"blue@bacon.istasty\", admin: nil, created_at: nil, updated_at: nil>"
# "blue bacon"

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