portfolio_helper.rb

module PortfolioHelper
  def portfolio_prev_next
   items = @pages.find(:all,
                       :in_directory => "/portfolio",
                       :sort_by      => "title")
   portfolio = @pages.find(:title => "Portfolio")
   current = @pages.find(:title => @page.title,
                         :in_directory => "/portfolio")

   index = items.index(current)
   prev_page = items.first == current ? portfolio : items[index-1]
   next_page = items.last == current ? portfolio : items[index+1]

   html = <<-HTML
     <a href="..#{prev_page.url}" id="back">
       &larr; #{h(prev_page.title)}
     </a>
     <a href="..#{next_page.url}" id="forward">
       #{h(next_page.title)} &rarr;
     </a>
   HTML

   return html
  end
end

Webby::Helpers.register(PortfolioHelper)