Module: HighCarb::SlidesController

Included in:
RackApp
Defined in:
lib/highcarb/slides_controller.rb

Instance Method Summary collapse

Instance Method Details

#load_asset(asset_name, css_class = []) ⇒ Object 



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# File 'lib/highcarb/slides_controller.rb', line 97

def load_asset(asset_name, css_class = [])
  asset_path = assets_root.join(asset_name)
  asset_url = "/assets/#{ERB::Util.h asset_name}"
  asset_type = nil

  if not css_class.empty?
    # Check if the css_class list contains any of the valid classes
    asset_type = (%w(image style javascript) & css_class).first
  end

  if asset_type.nil?
    # If the class attribute has no known class, infer it with the MIME type
    mime_type = MIME::Types.type_for(asset_name).first
    asset_type =
      if (mime_type and mime_type.media_type == "image")
        "image"
      elsif mime_type.to_s == "text/css"
        "style"
      elsif mime_type.to_s == "application/javascript" or asset_path.extname == "coffee"
        "javascript"
      end
  end

  case asset_type
  when "image"
    %[<img class="asset" src="#{asset_url}">]

  when "style"
    %[<link href="#{asset_url}" rel="stylesheet">]

  when "javascript"
    %[<script src="#{asset_url}"></script>]

  else
    %[<a href="#{asset_url}" target="_blank">#{ERB::Util.h asset_name}</script>]
  end

end

#load_snippet(snippet_name) ⇒ Object 



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# File 'lib/highcarb/slides_controller.rb', line 68

def load_snippet(snippet_name)
  snippet_path = root.join("snippets", snippet_name)
  snippet_html_cached = root.join("tmp", "snippets",
                                  Digest::MD5.new.tap {|digest| digest << snippet_path.read }.hexdigest + ".html")

  if snippet_html_cached.exist? and snippet_html_cached.mtime > snippet_path.mtime

    snippet_html_cached.read

  else

    content = begin
      IO.popen(["pygmentize", "-f", "html", "-O", "noclasses=true", snippet_path.to_s]).read
    rescue Errno::ENOENT
      if not @pygmentize_error_shown
        STDERR.puts "\033[31mpygmentize could not be used. You have to install it if you want to highlight the snippets."
        STDERR.puts "The snippets will be included with no format\033[m"
        @pygmentize_error_shown = true
      end

      %[<pre class="raw-snippet">#{ERB::Util.h snippet_path.read}</pre>]
    end

    snippet_html_cached.dirname.mkpath
    snippet_html_cached.open("w") {|f| f.write content }
    content
  end
end

#slides ⇒ Object 



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# File 'lib/highcarb/slides_controller.rb', line 7

def slides
  output = []

  # Load the content from the sources
  root.join("slides").children.sort.each do |slide_file|
    # Only use non-hidden files
    if slide_file.file? and slide_file.basename.to_s !~ /^\./
      case slide_file.extname.downcase
      when ".haml"
        output << Haml::Engine.new(slide_file.read).render

      when ".html"
        output << slide_file.read

      when ".md"
        output << Kramdown::Document.new(slide_file.read).to_html

      else
        STDERR.puts "\033[31mCan not parse #{slide_file}\033[m"
      end
    end
  end

  page = Nokogiri::HTML.parse(output.join)

  # Find the <snippet> tags and replace with the content from a
  # file located under the snippet/ directory
  page.search("snippet").each do |snippet_tag|
    snippet_tag.replace load_snippet(snippet_tag.inner_text.strip)
  end

  # Find the <asset> tags and replace with link, script or img,
  # depending on the MIME type
  page.search("asset").each do |asset_tag|
    asset_tag.replace load_asset(asset_tag.inner_text.strip, asset_tag.attributes["class"].to_s.split)
  end

  # Find the <external> tags and replace with <a>
  # The text shown will be reduced
  page.search("external").each do |external_tag|
    href = ERB::Util.h(external_tag.inner_text.strip)

    text = href.gsub(/\w+:\/+/, "")
    text = text[0,45] + "&hellip;" if text.length > 45

    external_tag.replace %[<a class="external" href="#{href}" target="_blank" title="Open #{href} in a new window">#{text}</a>]
  end

  # Append a server side generated identifier. This helps to identify them
  # both in presenter- and remote-control-mode
  last_slide_id = 0
  page.search(".slide").each do |slide_node|
    last_slide_id += 1
    slide_node["data-slide-id"] = last_slide_id.to_s
  end

  # Response with everything
  output = page.at("body").inner_html
  throw :response, [200, {'Content-Type' => 'text/html'}, output]
end