Question

class Foo < ActiveRecord::Base {
starts_at datetime;
ends_at datetime;
}

How do I enforce a check which verifies if ends_at is after starts_at?

Answer 1

Use the validate macro and pass a custom method.

class Foo < ActiveRecord::Base

  validate :validate_timeline

  protected

    def validate_timeline
      unless ends_at > starts_at
        errors.add(:ends_at, "end date cannot precede start date")
      end
    end
end