HTML Tag Scraper

tag_scraper.rb

## Make sure you install nokogiri: 'gem install nokogiri'
require 'nokogiri'
require 'set'

HTML5_TAGS = [
              "section", "nav", "article",
              "aside", "hgroup", "header",
              "footer", "figure", "figcaption",
              "data", "time", "mark",
              "ruby", "rt", "rp",
              "bdi", "wbr", "embed",
              "video", "audio", "source",
              "track", "canvas", "svg",
              "math", "datalist", "keygen",
              "output", "progress", "meter",
              "details", "summary", "command",
              "menu", "input:color", "input:date",
              "input:datetime", "input:datetime-local",
              "input:email", "input:month", "input:number",
              "input:range", "input:search", "input:tel",
              "input:time", "input:url", "input:week"
             ]

def scrape_tags_recursively(html)
  tags = Set.new

  html.elements.each do |element|
    if element.name == "input"
      tags << "input:#{element.attributes["type"].value}" # Get type attribute for input tags.
    else
      tags << element.name # Get tag name for any non-input tag.
    end
    tags |= scrape_tags_recursively(element) if element.children # recur on every child element.
  end

  return tags
end

def main
  unless ARGV[0]
    print "Enter HTML file to parse: "
  end
  ARGV[0] ||= gets.chomp # Type in file in none entered on command line.
  tags = Set.new
  
  unless ARGV[0].empty? 
    begin
      html = Nokogiri::HTML open(ARGV[0])
    rescue
      puts "Could not load file"
      return
    end
    tags |= scrape_tags_recursively(html)
  else # If no file is entered, scrape every HTML file in the current directory.
    ARGV[0] = "all files"
    Dir.foreach(".") do |file|
      if file.match(/^.+\.html$/i)
        html = Nokogiri::HTML open(file)
        tags |= scrape_tags_recursively(html)
      end
    end
  end
  

  puts "\nHTML tags in #{ARGV[0]}:"
  tags.sort.each {|tag| puts tag}
  puts "\nHTML5 Tags in #{ARGV[0]}:"
  tags.sort.each {|tag| puts tag if HTML5_TAGS.include?(tag)}
end

main if __FILE__ == $0