RailsCasts downloader

README.md

RailsCasts downloader

A utility script to automatically download all episodes of Ryan Bates' screencast series RailsCasts.

download.rb

require 'dotenv'
require 'nokogiri'

Dotenv.load

class Episode
  attr_reader :slug, :free

  def initialize(options = {})
    @slug = options[:slug]
    @free = options[:free]
  end

  def file_slug
    nr, title = slug.split('-', 2)
    [nr.rjust(3, '0'), title].join('-')
  end

  def source_code_basename
    "#{file_slug}.zip"
  end

  def source_code_url
    "http://media.railscasts.com/assets/episodes/sources/#{file_slug}.zip"
  end

  def video_basename
    "#{file_slug}.mp4"
  end

  def video_url
    if free
      "http://media.railscasts.com/assets/episodes/videos/#{video_basename}"
    else
      "http://media.railscasts.com/assets/subscriptions/#{subscription_secret}/videos/#{video_basename}"
    end
  end

  def subscription_secret
    ENV.fetch('SUBSCRIPTION_SECRET')
  end
end

f = File.open("list.html")
doc = Nokogiri::HTML(f)
f.close

episodes = doc.css('tr.episode td:nth-child(2)').map do |episode_cell|
  slug = episode_cell.at_css('a').attributes['href'].text.gsub(%r{/episodes/}, '')
  revised = episode_cell.at_css('a').text.end_with?('(revised)')
  pro = !!episode_cell.at_css('em')
  free = !revised && !pro
  Episode.new(slug: slug, free: free)
end

episodes.sort_by!(&:file_slug)

base_dir = '/mnt/sdb1/koronen/Downloads/RailsCasts'
File.open('d.sh', 'w') do |f|
  f.puts "#!/bin/bash"
  f.puts "set -e"

  episodes.each do |episode|
    episode_dir = File.join(base_dir, episode.file_slug)
    FileUtils.mkdir_p episode_dir

    source_code_file = File.join(episode_dir, episode.source_code_basename)
    f.puts "[ -f \"#{source_code_file}\" ] || wget -O \"#{source_code_file}\" \"#{episode.source_code_url}\" || true"

    video_file = File.join(episode_dir, episode.video_basename)
    f.puts "[ -f \"#{video_file}\" ] || wget -O \"#{video_file}\" \"#{episode.video_url}\""
  end
end

Gemfile

source 'https://rubygems.org'

ruby '2.1.0'

gem 'dotenv', '~> 0.11.1'
gem 'mechanize', '~> 2.7.3'
gem 'nokogiri', '~> 1.6.2'

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    domain_name (0.5.18)
      unf (>= 0.0.5, < 1.0.0)
    dotenv (0.11.1)
      dotenv-deployment (~> 0.0.2)
    dotenv-deployment (0.0.2)
    http-cookie (1.0.2)
      domain_name (~> 0.5)
    mechanize (2.7.3)
      domain_name (~> 0.5, >= 0.5.1)
      http-cookie (~> 1.0)
      mime-types (~> 2.0)
      net-http-digest_auth (~> 1.1, >= 1.1.1)
      net-http-persistent (~> 2.5, >= 2.5.2)
      nokogiri (~> 1.4)
      ntlm-http (~> 0.1, >= 0.1.1)
      webrobots (>= 0.0.9, < 0.2)
    mime-types (2.3)
    mini_portile (0.6.0)
    net-http-digest_auth (1.4)
    net-http-persistent (2.9.4)
    nokogiri (1.6.2.1)
      mini_portile (= 0.6.0)
    ntlm-http (0.1.1)
    unf (0.1.4)
      unf_ext
    unf_ext (0.0.6)
    webrobots (0.1.1)

PLATFORMS
  ruby

DEPENDENCIES
  dotenv (~> 0.11.1)
  mechanize (~> 2.7.3)
  nokogiri (~> 1.6.2)