external_links.rb

# require "typhoeus"

# Nanoc::Extra::Checking::Checks.send(:remove_const, :ExternalLinks)
# module Nanoc::Extra::Checking::Checks
#   class ExternalLinks < Nanoc::Extra::Checking::Check
#     identifiers :external_links, :elinks
#     @count = 4

#     class << self
#       attr_accessor :count
#     end

#     def run
#       hrefs =
#         Nanoc::Extra::LinkCollector.new(
#           self.output_filenames.select { |f|
#             File.extname(f) == ".html"
#           }, :external
#         ).filenames_per_href

#       list = hrefs.keys.select { |u| u =~ %r!https?://! }
#       self.find_invalid(list).each do |l|
#         filenames = hrefs[l]
#         filenames.map do |f|
#           self.add_issue("#{l} is broken, fix it", subject: f)
#         end
#       end
#     end

#     def find_invalid(hrefs)
#       self.class.count.times do |i|
#         hydra = Typhoeus::Hydra.new(max_concurrency: 20)
#         hrefs.each do |l|
#           hydra.queue(
#             req =
#               Typhoeus::Request.new(
#                 l, method: :head, followlocation: true)
#           )

#           req.on_complete do |r|
#             if [200, 301, 302].include?(r.response_code)
#               hrefs.delete(l)
#             end
#           end
#         end

#         hydra.run

#         if i < self.class.count
#           (hrefs.empty?) ? break : sleep(i * 5)
#         end
#       end

#       hrefs
#     end
#   end
# end