Applying google analytics to rake doc

Rakefile

@@ -8,7 +8,9 @@ task default: [:install, :spec]
 
 RSpec::Core::RakeTask.new(:spec)
 
-YARD::Rake::YardocTask.new(:doc) do |t|
+task doc: [:yarddoc, :apply_google_analytics]
+
+YARD::Rake::YardocTask.new(:yarddoc) do |t|
   t.files   = ['lib/**/*.rb', 'samples/**/*.rb']   # optional
   #t.options = ['--any', '--extra', '--opts'] # optional
 end
@@ -23,4 +25,51 @@ task benchmark: [:install] do
       end
     end
   end
-end
+end
+
+task :apply_google_analytics do
+  # The string to replace in the html document. This is chosen to be the end
+  # body </body> tag. So the script can be injected as the last thing in the
+  # document body.
+  string_to_replace = "</body>"
+  # This is the string to replace with. It include the google analytics script
+  # as well as the end </body> tag.
+  string_to_replace_with = <<-EOF
+    <script>
+      (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+      (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+      m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+      })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+
+      ga('create', 'UA-54811605-1', 'auto');
+      ga('send', 'pageview');
+
+   </script>
+  </body>
+  EOF
+
+  files = Dir.glob("doc/**/*.html")
+
+  files.each do |html_file|
+    puts "Processing file: #{html_file}"
+    contents = ""
+    # Read the file contents
+    file =  File.open(html_file)
+    file.each { |line| contents << line }
+    file.close
+
+    # If the file already has google analytics tracking info, skip it.
+    if contents.include?(string_to_replace_with)
+      puts "Skipped..."
+      next
+    end
+
+    # Apply google analytics tracking info to the html file
+    contents.gsub!(string_to_replace, string_to_replace_with)
+
+    # Write the contents with the google analytics info to the file
+    file =  File.open(html_file, "w")
+    file.write(contents)
+    file.close
+  end
+end