Errata

Page 48 (Chapter 6)

Reference: chapter06/app/models/page.rb#L19

The make_slug method is missing an early return guard clause. This is needed for when the title is nil. It should be:

def make_slug
  return unless title

  self.slug = title
                .downcase   
                .gsub(/[_ ]/, '-')
                .gsub(/[^-a-z0-9+]/, '')
                .gsub(/-{2,}/, '-')
                .gsub(/^-/, '')
                .chomp('-')
end

Reported on 2023-12-31 by Hiroaki Satou