Here are some ready built filters to use with TextTube. If you write any you think would be useful, send me a pull request!

If you're having a problem with the TextTube::InsideBlock filter on Heroku it could be because of the version of Libxml2 it uses, as the problem given here states, which means Nokogiri won't always work properly on Heroku. When using the InsideBlock filter this can be a problem, so use the hpricot branch instead.

Because of the problems with Nokogiri, from v1.1.0 it's been replaced by Oga. If you want alternatives then look in the source for the other versions, or someone could be helpful and send in a plugin with Ox or some other parser doing the work :)

Add this line to your application's Gemfile:

gem 'texttube_baby'

And then execute:

$ bundle install

though I'm a fan of sandboxing my gems, so:

$ bundle install --binstubs --path vendor.noindex

(the .noindex stops OSX Spotlight indexing it, that's just my little tip to you;)

Or install it yourself as:

$ gem install texttube_baby

If you'd don't want your links inline and would prefer to have them at the bottom of the document, then you can use this:

require 'texttube/base'
require 'texttube/baby/link_reffing'

class TextWithLinks < TextTube::Base
  register TextTube::Baby::LinkReffing
end

s = TextWithLinks.new %q!Iain's blog[[http://iainbarnett.me.uk|My blog]] is good. Erik Hollensbe's blog[[http://erik.hollensbe.org/|Holistic Engineering]] is also good, as is James Coglan's blog[[http://blog.jcoglan.com/|The If Works]]!

s.filter

and it will produce this:

# => "Iain's blog[&#8304;](#0 "Jump to reference") is good. Erik Hollensbe's blog[&sup1;](#1 "Jump to reference") is also good, as is James Coglan's blog[&sup2;](#2 "Jump to reference")\n<div markdown='1' id='reflinks'>\n<a name="0"></a>&#91;0&#93; [http://iainbarnett.me.uk](http://iainbarnett.me.uk "http://iainbarnett.me.uk") My blog\n\n\n<a name="1"></a>&#91;1&#93; [http://erik.hollensbe.org/](http://erik.hollensbe.org/ "http://erik.hollensbe.org/") Holistic Engineering\n\n\n<a name="2"></a>&#91;2&#93; [http://blog.jcoglan.com/](http://blog.jcoglan.com/ "http://blog.jcoglan.com/") The If Works\n\n</div>"

Run that through a markdown parser and you get:

<p>Iain's blog<a href="#0" title="Jump to reference">&#8304;</a> is good. Erik Hollensbe's blog<a href="#1" title="Jump to reference">&sup1;</a> is also good, as is James Coglan's blog<a href="#2" title="Jump to reference">&sup2;</a></p>

<div markdown='1' id='reflinks'>
<a name="0"></a>&#91;0&#93; [http://iainbarnett.me.uk](http://iainbarnett.me.uk "http://iainbarnett.me.uk") My blog


<a name="1"></a>&#91;1&#93; [http://erik.hollensbe.org/](http://erik.hollensbe.org/ "http://erik.hollensbe.org/") Holistic Engineering


<a name="2"></a>&#91;2&#93; [http://blog.jcoglan.com/](http://blog.jcoglan.com/ "http://blog.jcoglan.com/") The If Works

</div>

Using this will probably end up with also using InsideBlock, to transform the markdown inside the div.

Sometimes it'd be useful to wrap some markdown with HTML, for example:

<div id="notes">

* first
* second
* third

</div>

If you put this through a markdown parser the markdown won't get parsed:

require 'rdiscount'
s = "<div id="notes">\n\n* first\n* second\n* third\n\n</div>\n"
puts RDiscount.new(s).to_html

This is the output:

<div id="notes">

* first
* second
* third

</div>

My brilliant idea to get around this is to add an HTML attribute of markdown='1' to HTML tags that you want the markdown parser to look inside:

<div id="notes" markdown='1'>

* first
* second
* third

</div>

Trying this with InsideBlock gives:

    puts TextTube::Baby::InsideBlock.run s

<div id="notes">
<ul>
<li>first</li>
<li>second</li>
<li>third</li>
</ul>

</div>

To use it as a filter:

require 'texttube/base'

class MyFilter < TextTube::Baby::Base
  register TextTube::Baby::InsideBlock
end

myf = MyFilter.new(s)
# => "<div id="notes" markdown='1'>\n\n* first\n* second\n* third\n\n</div>\n"

puts myf.filter

Gives:

<div id="notes">
<ul>
<li>first</li>
<li>second</li>
<li>third</li>
</ul>

</div>

Filters an HTML code block and marks it up with coderay:

require 'texttube/base'
require 'texttube/baby/coderay'
require 'rdiscount' # a markdown parser

class TextWithCode < TextTube::Baby::Base
  register do
    filter_with :rdiscount do |text|
      RDiscount.new(text).to_html
    end
  end
  register TextTube::Baby::Coderay
end

s = TextWithCode.new <<'STR'
# FizzBuzz #

    ::::ruby
    (1..100).each do |n| 
      out = "#{n}: "
      out << "Fizz" if n % 3 == 0
      out << "Buzz" if n % 5 == 0
      puts out
    end

That's all folks!
STR
# => "# FizzBuzz #\n\n    ::::ruby\n    (1..100).each do |n| \n      out = "\#{n}: "\n      out << "Fizz" if n % 3 == 0\n      out << "Buzz" if n % 5 == 0\n      puts out\n    end\n\nThat's all folks!\n"


puts s.filter

Produces:

<h1>FizzBuzz</h1>

<pre><code class="CodeRay">(<span class="integer">1</span>..<span class="integer">100</span>).each <span class="keyword">do</span> |n| 
  out = <span class="string"><span class="delimiter">"</span><span class="inline"><span class="inline-delimiter">#{</span>n<span class="inline-delimiter">}</span></span><span class="content">: </span><span class="delimiter">"</span></span>
  out &lt;&lt; <span class="string"><span class="delimiter">"</span><span class="content">Fizz</span><span class="delimiter">"</span></span> <span class="keyword">if</span> n % <span class="integer">3</span> == <span class="integer">0</span>
  out &lt;&lt; <span class="string"><span class="delimiter">"</span><span class="content">Buzz</span><span class="delimiter">"</span></span> <span class="keyword">if</span> n % <span class="integer">5</span> == <span class="integer">0</span>
  puts out
<span class="keyword">end</span></code></pre>

<p>That's all folks!</p>

The language was specified with a leading ::::ruby. It didn't have to be as the default is to use Ruby, but if you want to use any other of the coderay supported languages, that's how to do it.

Transforms CSS written in British English into its ugly sister from across the pond. Inspired by visualidiot's SpiffingCSS.

content = <<CSS
  body {
    background-colour: darkgrey;
    background-photograph: url(logo.gif);
    transparency: .7;
  
    font: 72px "Comic Sans", cursive !please;
    font-weight: plump;
    p { text-align: centre }
    fieldset input {
      text-transform: capitalise;
    }
  }
CSS

require 'texttube/base'
require 'texttube/baby/spiffing'

class CssString < TextTube::Base
  register TextTube::Baby::Spiffing
end

puts CssString.new(content).filter

body {
  background-color: darkgray;
  background-image: url(logo.gif);
  opacity: .7;

  font: 72px "Comic Sans", cursive !important;
  font-weight: bold;
  p { text-align: center }
  fieldset input {
    text-transform: capitalize;
  }
}

God save the Queen!

1. Fork it ( https://github.com/[my-github-username]/TextTubeBaby/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request