File: README — Documentation for texttube (5.1.1)

TextTube

Pass a string through filters to transform it.

Note!

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.

Build status

Master branch:

Develop branch:

Why?

I wanted to run a filter across articles I'd written for my blog, but also for the atom feed to the blog. Both needed some of the filters, but the atom feed needed less of them and slightly different options.

What does it do?

You want to filter/transform a string. You also want to run several filters across it, usually in the same way but sometimes just some of them, sometimes in a slightly different order. Object orientated programming will come to our rescue!

The string is the instance.
Modules hold groups of reusable filters.
A class defines which filters to use.
The method for running the filters will also allow ordering.

In practice this means:

require 'texttube/filterable'

module AFilter
  extend TextTube::Filterable

  filter_with :double do |text|
    text * 2
  end

  filter_with :triple do |text|
    text * 3
  end
end

module BFil
  extend TextTube::Filterable

  filter_with :spacial do |current,options|
    current.split(//).join " " 
  end
end

require 'texttube/base'

class NeuS < TextTube::Base
  register BFil
  register AFilter
  register do # on the fly
    filter_with :dashes do |text|
      "---#{text}---"
    end
  end
end

Now there is a class NeuS which will run filters :spacial, :double, :triple, and :dashes in that order, on a given string. For example:

n = NeuS.new "abc"

Running all of the filters:

n.filter
# => "---a b ca b ca b ca b ca b ca b c---"

Or just some of the filters:

n.filter :spacial
# => "a b c"
n.filter :spacial, :dashes
# => "---a b c---"

Run them more than once:

n.filter :double, :triple, :double
# => "abcabcabcabcabcabcabcabcabcabcabcabc"

Creating a filter

Make something filterable:

require 'texttube/filterable'

module AnotherFilter
  extend TextTube::Filterable

  filter_with :copyright do |text|
    text << " ©#{Time.now.year}. "
  end

  filter_with :number do |text,options|
    text * options[:times].to_i
  end
end

That's all there is to creating a filter.

Creating a filter class

The class picks which filters to use, and can add filters on the fly, by using register:

require 'texttube/base'

class MyString < TextTube::Base
  register AnotherFilter
  register do
    filter_with :my_name do |text|
      text.gsub "Iain Barnett", %q!<a href="iainbarnett.me.uk" title="My blog">Iain Barnett</a>!
    end
  end
end

s = MyString.new "Let me introduce Iain Barnett. He writes Ruby code."
# => "Let me introduce Iain Barnett. He writes Ruby code."

MyString.options.merge! :number => {times: 2}
# => {:number=>{:times=>2}}

s.filter
# => "Let me introduce <a href="iainbarnett.me.uk" title="My blog">Iain Barnett</a>. He writes Ruby code. ©2013. Let me introduce <a href="iainbarnett.me.uk" title="My blog">Iain Barnett</a>. He writes Ruby code. ©2013. "

The Filters

Here are some ready built filters to use.

LinkReffing

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/filters/link_reffing'

class TextWithLinks < TextTube::Base
  register TextTube::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.

InsideBlock

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::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::Base
  register TextTube::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>

Coderay

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

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

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

FizzBuzz

(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!

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.

Spiffing

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/filters/spiffing'

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

puts CssString.new(content).filter

# output:

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!

Contributors

Many thanks to Eleni Karinou and Annette Smith for brainsplatting a new name for the library, and after many unusable and clearly disturbing suggestions, to Annette for the final name (and its future spin off, which will remain secret for now).

Licence

MIT Licence

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

i.e. be good