Rakefile task for querying Zemanta for keywords

zemanta.rb

require 'yaml'
require 'rubygems'
require 'zemanta' # gem install zemanta

def get_zemanta_terms(content)
  $stderr.puts "Querying Zemanta..."
  zemanta = Zemanta.new "xxxxxxxxxxxxxxxxxxxxxxxx"
  suggests = zemanta.suggest(content)
  res = []
  suggests['keywords'].each {|k|
    res << k['name'].downcase.gsub(/\s*\(.*?\)/,'').strip if k['confidence'] > 0.02
  }
  res
end

desc "Add Zemanta keywords to post YAML"
task :add_keywords, :post do |t, args|
  file = args.post
  if File.exists?(file)
    # Split the post by --- to extract YAML headers
    contents = IO.read(file).split(/^---\s*$/)
    headers = YAML::load("---\n"+contents[1])
    content = contents[2].strip
    # skip adding keywords if it's already been done
    unless headers['keywords'] && headers['keywords'] != []
      begin
        $stderr.puts "getting terms for #{file}"
        # retrieve the suggested keywords
        keywords = get_zemanta_terms(content)
        # insert them in the YAML array
        headers['keywords'] = keywords
        # Dump the headers and contents back to the post
        File.open(file,'w+') {|file| file.puts YAML::dump(headers) + "---\n" + content + "\n"}
      rescue
        $stderr.puts "ERROR: #{file}"
      end
    else
      puts "Skipped: post already has keywords header"
    end
  else
    puts "No such file."
  end
end