_plugins/pageless-redirects.rb

   1 # Pageless Redirect Generator
   2 #
   3 # Generates redirect pages based on YAML or htaccess style redirects
   4 #
   5 # To generate redirects create _redirects.yml, _redirects.htaccess, and/or _redirects.json in the Jekyll root directory
   6 # both follow the pattern alias, final destination.
   7 #
   8 # Example _redirects.yml
   9 #
  10 #   initial-page   : /destination-page
  11 #   other-page     : http://example.org/destination-page
  12 #   "another/page" : /destination-page
  13 #
  14 #  Result:
  15 #   Requests to /initial-page are redirected to /destination-page
  16 #   Requests to /other-page are redirected to http://example.org/destination-page
  17 #   Requests to /another/page are redirected to /destination-page
  18 #
  19 #
  20 # Example _redirects.htaccess
  21 #
  22 #   Redirect /some-page /destination-page
  23 #   Redirect 301 /different-page /destination-page
  24 #   Redirect cool-page http://example.org/destination-page
  25 #
  26 #  Result:
  27 #   Requests to /some-page are redirected to /destination-page
  28 #   Requests to /different-page are redirected to /destination-page
  29 #   Requests to /cool-page are redirected to http://example.org/destination-page
  30 #
  31 #
  32 # Example _redirects.json
  33 #
  34 #   {
  35 #     "some-page"        : "/destination-page",
  36 #     "yet-another-page" : "http://example.org/destination-page",
  37 #     "ninth-page"       : "/destination-page"
  38 #   }
  39 #
  40 #  Result:
  41 #   Requests to /some-page are redirected to /destination-page
  42 #   Requests to /yet-another-page are redirected to http://example.org/destination-page
  43 #   Requests to /ninth-page are redirected to /destination-page
  44 #
  45 #
  46 # Author: Nick Quinlan
  47 # Site: http://nicholasquinlan.com
  48 # Plugin Source: https://github.com/nquinlan/jekyll-pageless-redirects
  49 # Plugin License: MIT
  50 # Plugin Credit: This plugin borrows heavily from alias_generator (http://github.com/tsmango/jekyll_alias_generator) by Thomas Mango (http://thomasmango.com)
  51
  52 require 'json'
  53
  54 module Jekyll
  55
  56   class PagelessRedirectGenerator < Generator
  57
  58     def generate(site)
  59       @site = site
  60
  61       process_yaml
  62       process_htaccess
  63       process_json
  64     end
  65
  66     def process_yaml
  67       file_path = @site.source + "/_redirects.yml"
  68       if File.exists?(file_path)
  69         YAML.load_file(file_path).each do | new_url, old_url |
  70           generate_aliases( old_url, new_url )
  71         end
  72       end
  73     end
  74
  75     def process_htaccess
  76       file_path = @site.source + "/_redirects.htaccess"
  77       if File.exists?(file_path)
  78         # Read the file line by line pushing redirects to the redirects array
  79         file = File.new(file_path, "r")
  80         while (line = file.gets)
  81           # Match the line against a regex, if it matches push it to the object
  82           /^Redirect(\s+30[1237])?\s+(.+?)\s+(.+?)$/.match(line) { | matches |
  83             generate_aliases( matches[3], matches[2])
  84           }
  85         end
  86         file.close
  87       end
  88     end
  89
  90     def process_json
  91       file_path = @site.source + "/_redirects.json"
  92       if File.exists?(file_path)
  93         file = File.new(file_path, "r")
  94         content = JSON.parse(file.read)
  95         content.each do |new_url, old_url|
  96             generate_aliases(old_url, new_url)
  97         end
  98         file.close
  99       end
 100     end
 101
 102     def generate_aliases(destination_path, aliases)
 103       alias_paths ||= Array.new
 104       alias_paths << aliases
 105       alias_paths.compact!
 106
 107       alias_paths.flatten.each do |alias_path|
 108         alias_path = alias_path.to_s
 109
 110         alias_dir  = File.extname(alias_path).empty? ? alias_path : File.dirname(alias_path)
 111         alias_file = File.extname(alias_path).empty? ? "index.html" : File.basename(alias_path)
 112
 113         fs_path_to_dir   = File.join(@site.dest, alias_dir)
 114         alias_index_path = File.join(alias_dir, alias_file)
 115
 116         FileUtils.mkdir_p(fs_path_to_dir)
 117         File.open(File.join(fs_path_to_dir, alias_file), 'w') do |file|
 118           file.write(alias_template(destination_path))
 119         end
 120
 121         (alias_index_path.split('/').size + 1).times do |sections|
 122           @site.static_files << PagelessRedirectFile.new(@site, @site.dest, alias_index_path.split('/')[1, sections + 1].join('/'), '')
 123         end
 124       end
 125     end
 126
 127     def alias_template(destination_path)
 128       <<-EOF
 129 <!DOCTYPE html>
 130 <html>
 131 <head>
 132 <title>Redirecting...</title>
 133 <link rel="canonical" href="#{destination_path}"/>
 134 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
 135 <meta http-equiv="refresh" content="0; url=#{destination_path}" />
 136 </head>
 137 <body>
 138   <p><strong>Redirecting...</strong></p>
 139   <p><a href='#{destination_path}'>Click here if you are not redirected.</a></p>
 140   <script>
 141     document.location.href = "#{destination_path}";
 142   </script>
 143 </body>
 144 </html>
 145       EOF
 146     end
 147   end
 148
 149   class PagelessRedirectFile < StaticFile
 150     require 'set'
 151
 152     def destination(dest)
 153       File.join(dest, @dir)
 154     end
 155
 156     def modified?
 157       return false
 158     end
 159
 160     def write(dest)
 161       return true
 162     end
 163   end
 164 end