dirtyword.rb

require 'sinatra'
require 'sanitize'

TO_REMOVE = ["", " ", " "]

get '/' do
  <<-HTML
    <form method="post" action="sanitize">
      <textarea name="dirty" style="width:100%;height:800px;"></textarea>
      <input type="submit" value="Submit">
    </form>
  HTML
end

post '/sanitize' do
  dirty = params[:dirty]
  clean = Sanitize.clean(dirty, 
    :elements => ['a', 'p', 'b', 'i', 'blockquote'], 
    :attributes => {'a' => ['href']}, 
    :allow_comments => false,
    :transformers => [
      lambda {|env|
        # fixes https://github.com/rgrove/sanitize/issues/17
        env[:node].remove if env[:node].name == 'style'
        {}
      },
      lambda {|env|
        env[:node].remove if env[:node].content == "&nbsp;" || env[:node].content == "" || env[:node].content == " "
      }
    ]
  )
  
  <<-HTML
    <textarea name="dirty" style="width:100%;height:800px;">#{clean}</textarea>
  HTML
end