#272 Markdown with Redcarpet

How come you didn't do something like this? Was there any reason?

def markdown(text, options = nil)
  options ||= [:hard_wrap, :filter_html, :autolink, :no_intraemphasis, :fenced_code, :gh_blockcode]
  syntax_highlighter(Redcarpet.new(text, *options).to_html).html_safe
end

Hi Ryan and all,
how can I get in my textmate to show up new folder icon, I've tried everything I still get the same old icon, I'm using TM 1.5.9

@Ainars Same old icon? Not sure if you're referring to how Ryans drawer looks like, but he's using the TextMate MissingDrawer plugin.

Ryan, thanks for the plug. Create episode as always!

Hello Ryan,

Thanks for the screencast! When I use your example or the source code Nokogiri inserts HTML headers to the output of the syntax_highlighter method. I've fixed it by modifying the last line of that method.

def syntax_highlighter(html)
  doc = Nokogiri::HTML(html)
  doc.search("//pre[@lang]").each do |pre|
    pre.replace Albino.colorize(pre.text.rstrip, pre[:lang])
  end
  doc.at_css("body").inner_html.to_s
end

Why is it that the output in the screencast is different?

Love the 'casts...Thanks, Ryan!

Another great cast. You have an uncanny ability to cover topics as I need them. I got RedCloth going this morning, but upon seeing this cast I will be switching ASAP. Thanks Ryan!

Thanks for your screen.

A Markdown TextEditor with markitup and redcarpet ,support rails 3

https://github.com/ZhangHanDong/rails_markitup

I am getting the following error in my log when i try and use ruby block...

ActionView::TemplateError (No such file or directory - posix_spawnp)

Any ideas why? or how to fix?

:D

Thanks Ryan.

Is it possible to use pygments on Heroku?

Great screencast. Thanks Ryan.

Again, Just awesome, and Just in time.???

Is there a ruby alternative to pigments? Seems strange to use a python library.

I cant install redcarpet, im using windows :(! "Error: Failed to build gem native extensions." Someone could?

To do this with heroku, change syntax_highlighter to the following:

  def syntax_highlighter(html)
    doc = Nokogiri::HTML(html)
    doc.search("//pre[@lang]").each do |pre|
      lang = pre[:lang]
      code = pre.text.rstrip
      request = Net::HTTP.post_form(URI.parse('http://pygments.appspot.com/'), {'lang'=>lang, 'code'=>code})
      pre.replace request.body
    end
    doc.to_s
  end

If you are having problems with the Albino gem returning nothing, make sure you are running Pygmentize under Python2.

I was encountering this issue from the command line:

pygmentize -l ruby -f html -O encoding=utf-8 test.rb

*** Error while highlighting:
TypeError: must be str, not bytes
   (file "/usr/lib/python3.2/codecs.py", line 356, in write)

In Arch Linux for example the default Python is Python3.2, installing Pygmentize under Python2.7 solved this for me.

Anyone knows why indentation is not correct, or which part is responsible for that, Albino or pygmentize?

it looks like this

def syntax_highlighter(html)
                doc = Nokogiri::HTML(html)
                  doc.search("//pre[@lang]").each do |pre|
                    pre.replace Albino.colorize(pre.text.rstrip, pre[:lang])
                  end
                doc.css('body').inner_html.to_s
            end

instead of

def syntax_highlighter(html)
  doc = Nokogiri::HTML::DocumentFragment.parse(html)
  doc.css("pre[@lang]").each do |pre|
    pre.replace Albino.colorize(pre.text.rstrip, pre[:lang])
  end
  doc.to_s
end 

when I put this without parsing it with Nokogiri/Albino/Pyg, then it appears correct (using markdown only)

Hi,

when I try

ruby
 puts "hello world"

I get

<code>ruby<br> print "hello world" <br></code>

but not get
<pre lang="ruby">
Thanks for the podcast.

@ Everyone trying to to this on Heroku I know I am late but I set up a new appspot app that uses the new version of Pygments and wrote a little blog post about how to use it at http://iamaust.in/posts/3.

I hope this helps people, now you can colorize things like coffeescript and sass for your rails 3.1 apps

Hello,

I would like to know if there is a way to show the line numbers for the code blocks generated through Albino.

Thanks.

@nathan le Ray you can pull from my github a modified version of albino that allows you to pass options to pygments. https://github.com/austinbv/albino. To use this version of albion in your gemfile just add

gem albino, :git => git://github.com/austinbv/albino.git

I started with the pre-release version of the new redcarpet gem and then went about modifying the helper you outlined in your screencast. Based on the following from the wiki for the gem

Rendering with the Markdown object is done through Markdown#render. Unlike in the RedCloth API, the text to render is passed as an argument and not stored inside the Markdown instance, to encourage reusability.

I tried to change your helper. This is the basics of what i tried. I clearly don't know enough to see what must be obvious to experienced programmers.

def markdown
  markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML,
        :autolink => true, :space_after_headers => true)
end

I have a policy model, so in my show view I tried something like.

markdown.render(@policies.introduction)

Needless to say, this isn't working correctly for me. Thoughts, help?

Hi there, is it possible to embed a video (e.g. youtube video) using redcarpet?

I've implemented this months ago without any pain. But today when I moved my application to a newer debian-server, it told me "easy_install not found.

If you face the same trouble use:

sudo apt-get install python-pygments

Here's how I did it for a blog project using Rails 3.2 and Redcarpet 2.1 (minus the syntax highlighting). Some of the configuration options have been moved into the HTML renderer, while the more generic ones are still at the markdown layer:

module ApplicationHelper 
  def markdown(text)
    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML.new(
        :hard_wrap => true, :filter_html => true, :safe_links_only => true),
        :no_intraemphasis => true, :autolink => true)
    return markdown.render(text).html_safe
  end
end

Albino has been deprecated in favor of pygments.rb. This code combines both redcarpet 2.1 and pygments.rb

module ApplicationHelper
  class HTMLwithPygments < Redcarpet::Render::HTML
    def block_code(code, language)
      Pygments.highlight(code, :lexer => language)
    end
  end

  def markdown(text)
    renderer = HTMLwithPygments.new(:hard_wrap => true)
    options = {
      :fenced_code_blocks => true,
      :no_intra_emphasis => true,
      :autolink => true,
      :strikethrough => true,
      :lax_html_blocks => true,
      :superscript => true
    }
    Redcarpet::Markdown.new(renderer, options).render(text)
  end
end

The github repository for redcarpet has gone away, does anyone know what's happening with it?

https://github.com/tanoku/redcarpet

nice article

Given the changes with Redcarpet, I was not able to get the steps in this Railscast to work. But, I used it to help me understand what I was looking at in figuring out what to do next. I got Redcarpet working with my Rails 4, RC1 blog. If you'd like steps, you can peek at it here:

http://www.hamcois.com/articles/4

Hey all I had a question about this, I'm using 3.2 and was wondering how would I implement live preview using the example above?? i have it working where when I enter the new information it reads the markdown

then i enter

<script type="text/javascript">
$('#design_description').keyup(function () {
    var impt = $(this).val();
    $(".preview").html(impt);
});

</script>

in the bottom of the view.... its listening and showing the words but no markdown syntax is applied... how would I do this?

Update for anyone using RedCarpet 3.0.0

Using this RailsCast, just change the helper method to this:

def markdown(blogtext)
    renderOptions = {hard_wrap: true, filter_html: true}
    markdownOptions = {autolink: true, no_intra_emphasis: true}
    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML.new(renderOptions), markdownOptions)
    markdown.render(blogtext).html_safe
 end

Then in view just use

<%= markdown(@blog.body) %>

Notice they changed to sets of hashes for options. One hash of options for the Redcarpet::Render::HTML.new(options hash here)
and the second options hash for the Redcarpet::Markdown.new(renderer(this is where the renderer goes), markdown hash here). To understand, here are both without removing options into two variables.

def markdown(blogtext)
  markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML.new({hard_wrap: true, filter_html: true}), {autolink: true, no_intra_emphasis: true})
  markdown.render(blogtext).htm_safe
end

Check their github site to find out which options belongs in which options hash.

Thank you so much SimplizIT. That was very helpful. Please keep it up.