Short, Long and Pretty Urls - Using Sinatra & DataMapper to demonstrate different types of urls

main.rb

require 'sinatra'
require 'data_mapper'
require 'slim'
require 'digest/sha1'

DataMapper.setup(:default, ENV['DATABASE_URL'] || File.join("sqlite3://",settings.root, "development.db"))

class Note
  include DataMapper::Resource
  property :id,       Serial
  property :title,    String, :required => true
  property :content,  Text
  property :pretty,   String,  default: -> r,p { r.make_pretty }
  property :salt,     String,  default: -> r,p { (1+rand(8)).to_s }
  property :long,     String,  default: -> r,p { r.make_long }
  
  def make_pretty
    title.downcase.gsub(/\W/,'-').squeeze('-').chomp('-') 
  end
  
  def make_long
    Digest::SHA1.hexdigest(Time.now.to_s + title + id.to_s) 
  end
  
  def short
    (id.to_s + salt).reverse.to_i.to_s(36)
  end
end

get '/' do
  @notes = Note.all
  slim :index
end

post '/' do
  note = Note.create params[:note]
  redirect '/'
end

get '/pretty/:url' do
  @note = Note.first(:pretty => params[:url])
  slim :show
end

get '/short/:url' do
  @note = Note.get params[:url].to_i(36).to_s.reverse.chop 
  slim :show
end

get '/long/:url' do
  @note = Note.first(:long => params[:url])
  slim :show
end

__END__
@@layout
doctype html
html
  head
    meta charset="utf-8"
    title Short, Long & Pretty Urls
  body
    == yield

@@index
h1 Notes
form action="/" method="POST"
  input type="text" name='note[title]'
  br
  textarea name='note[content]' rows=12 cols=40
  input type="submit" value="Create"
-if @notes.any?
  ul#notes
    - @notes.each do |note|
      li #{note.title} <a href="/pretty/#{note.pretty}">Pretty</a> | <a href="/short/#{note.short}">Short</a> | <a href="/long/#{note.long}">Long</a>
- else
  h2 No Notes!
  
@@show
h1= @note.title
= @note.content