🎉 Book Website (#145)

* Basic script to modify html output

* Modify HTML of website

* Add makefile

* Compile website in CI

* Improve readme

website/modify_build.rb

@@ -0,0 +1,82 @@
+require 'pry'
+require 'nokogiri'
+
+# This class goes through the generated default LaTeX HTML and performs
+# several optimisations on the HTML. Nokogiri is used to facilitate the
+# modifications.
+
+class ModifyBuild
+  def self.build
+    new.build
+  end
+
+  def build
+    build_latex_html
+  end
+
+  def build_latex_html
+    system("rm -rf #{build_dir}/")
+    system("mkdir #{build_dir}/")
+    copy_source_to_local_dir_for_modification
+    list_of_files_to_modify.each do |filename|
+      modify_file(filename)
+    end
+  end
+
+  private
+
+  def modify_file(filename)
+    orig_text = File.read(filename)
+    text = fix_double_slashes(orig_text)
+    text = fix_navigation_bar(text)
+    File.open(filename, "w") {|file| file.puts text }
+  end
+
+  def list_of_files_to_modify
+    Dir.glob("#{build_dir}/*.html")
+  end
+
+  def copy_source_to_local_dir_for_modification
+    system("cd ../book/ && make website") unless source_website_output_exists?
+    system("cp -R ../book/#{build_dir}/* #{build_dir}")
+  end
+
+  def source_website_output_exists?
+    File.directory?("../book/#{build_dir}/")
+  end
+
+  def build_dir
+    'static_website_html'
+  end
+
+  def fix_double_slashes(text)
+    text.gsub(/\/\//, "/")
+  end
+
+  def fix_navigation_bar(text)
+    doc = Nokogiri::HTML(text)
+    elements = [doc.search('.chapterToc'), doc.search('.sectionToc'), doc.search('.subsectionToc')].flatten
+    elements.each do |n|
+      chapter_number_or_nothing = n.children[0].text.strip
+      hyperlink_node = n.children[1]
+      # remove unneeded text and merge into single a tag
+      n.children[0].remove
+      link_text = hyperlink_node.content
+      # no chapter number
+      if chapter_number_or_nothing.length == 0
+        content = hyperlink_node.to_s
+      else
+        link_node_content = %Q{
+        <span class="chapter_number">#{chapter_number_or_nothing}</span>
+        <span class="link_text">#{link_text}</span>
+        }
+        hyperlink_node.inner_html = link_node_content
+        content = hyperlink_node.to_s
+      end
+      n.inner_html = content
+    end
+    doc.to_html
+  end
+end
+
+ModifyBuild.build