app.rb

# Step 2
class HelloWorld
  def call(env)
    [200, {}, ['Hello World']]
  end
end

# # Step 3
# class HelloWorld
#   def call(env)
#     # Please, please, don't put params directly into the output
#     # like this. It's not safe from hackers!
#     [200, {}, ["Hello, #{env['QUERY_STRING']}"]]
#   end
# end

# # Step 4
# class HelloWorld
#   def call(env)
#     request = Rack::Request.new env

#     # Please, please, don't put params directly into the output
#     # like this. It's not safe from hackers!
#     [200, {}, ["Hello, #{request.params['person']}"]]
#   end
# end

# # Step 5
# class HelloWorld
#   def call(env)
#     request = Rack::Request.new env
#     # Please, please, don't open files blindly like this upon request
#     # from an external user. It's not safe from hackers!
#     file = File.open(request.params['q'] + '.html')

#     [200, {}, file]
#   end
# end

# # Step 6
# class HelloWorld
#   def call(env)
#     request = Rack::Request.new env
#     @person = request.params['person']

#     # Please, please, just don't do anything in this file. Use sinatra
#     # or rails to do this stuff. They're smarter than us! :)
#     file = File.open(request.params['q'] + '.html.erb')
#     template = ERB.new(file.read)
#     result = template.result(binding)

#     [200, {}, [result]]
#   end
# end

# # Step 7
# class HelloWorld
#   def call(env)
#     request = Rack::Request.new env
#     @person = request.params['person']

#     # This one is actually pretty safe. As we go up to higher-level and
#     # more complex gems they start to do more things like sanitization.
#     file = request.params['q'] + '.md'
#     require 'github/markup'
#     @page = GitHub::Markup.render(file, File.open(file).read)

#     # Please, please, just don't do anything in this file. Use sinatra
#     # or rails to do this stuff. They're smarter than us! :)
#     layout = File.open('layout.html.erb')
#     template = ERB.new(layout.read)
#     result = template.result(binding)

#     [200, {}, [result]]
#   end
# end

# # Step 8
# class HelloWorld
#   def call(env)
#     # Initial creation steps ("caching")
#       # Make a request object
#       # Find params, sanitize them and pass them to a template tool like
#       # markdown or ERB or github-markup
#       # Make the layout, pass in the page object we just created
#       # Save the plain html file to a folder named something like _site
#     # Now we just need to go back to HelloWorld4
#       # Or even better, use Apache or Nginx which are /much/ better at
#       # serving plain html pages.
#     # This is called caching, but we could do this without requesting
#     # webpages at all. This is what `jekyll build` does. So all you get
#     # is plain html pages with no need to boot a ruby server at all. This
#     # is what github-pages does (ie: username.github.io)

#     [200, {}, ['']]
#   end
# end