Super short & minimal wiki using Sinatra and DataMapper

Gemfile

# A sample Gemfile
source "https://rubygems.org"

gem 'sinatra'
gem 'sinatra-authentication'

gem 'data_mapper'
gem 'dm-sqlite-adapter'

gem 'rdiscount'
gem 'haml'

lilwiki.rb

require 'bundler'
require 'sinatra'
require 'rdiscount'
require 'haml'
require 'data_mapper'
require 'sinatra-authentication'

use Rack::Session::Cookie, 'shhhhhhhhhhhhhhh~'

class Page
  include DataMapper::Resource
  property :id, Serial
  property :title, String, :unique => true
  property :body, Text

  def html
    RDiscount.new(body).to_html
  end

  def slug
    title ? title.downcase.gsub(/[^a-z0-9 ]*/, '').gsub(/ /, '_') : 'home'
  end
end

class DmUser
  property :approved, Boolean, :default => false
  property :admin, Boolean, :default => false
end

DataMapper.setup(:default, ENV['DATABASE_URL'] || "sqlite3://#{Dir.pwd}/test.db")
DataMapper.auto_upgrade!

unless Page.first(:title => 'home')
  Page.create(:title => 'home', :body => "Welcome to Lil' Wiki!\n\n[A Page To Create](/A Page To Create)")
end

get '/' do
  show_page('home')
end

get '/:title' do
  show_page(params[:title])
end

get '/:title/edit' do
  if approved?
    @page = Page.first(:title => params[:title])
    haml :edit
  else
    haml :error
  end
end

post '/posts/:title' do
  if approved?  
    @page = Page.first(:title => params[:title]) || Page.create(:title => params[:title])
    @page.update(params)
    redirect "/#{params[:title]}"
  else
    haml :error
  end
end

def approved?
  current_user && current_user.approved?
end

def show_page(title)
  @page = Page.first(:title => title)
  if @page
    haml :page
  else
    @page = Page.new(:title => title)
    haml :edit
  end
end

__END__

@@ layout
!!! XML
!!!
%html
  %head
    %title Wiki
  %body
    %ul
      %li
        %a{:href => '/'} Home
      - if @page
        %li
          %a{:href => "/#{@page.slug}/edit"} Edit this page
      - if logged_in?
        %li
          %a{:href => '/logout'} Log out
      - else
        %li
          %a{:href => '/login'} Log in
        %li
          %a{:href => '/signup'} Sign up
    #page= yield

@@ page
%h1= @page.title
#body= @page.html

@@ edit
%h1= "Editing #{@page.title}"
%form{:method => "post", :action => "/posts/#{@page.title}"}
  %textarea{:name => "body"}= @page.body
  %br
  %input{:type => "submit"}

@@ error
You need to be approved before you can edit.