snippet.rb

# An example of how to use mounted apps and stil have acces to full paths within the apps.
#
# Created by Kematzy [ 2009-07-10 ]

require 'rubygems'
require 'sinatra/base'

# set the root of the whole app
APP_ROOT = File.dirname(File.expand_path(__FILE__)) unless defined?(APP_ROOT)


require 'sinatra/base'

# simple Sinatra::Extension
module Sinatra
  module MountedAtExample
    module Helpers
        
      ##
      # Simple method that generates the path to the app.
      #
      # ==== Examples
      #
      #   path_app            => '/'
      #   path_app('path')    => '/path'
      #   path_app(:path)     => '/path'
      #   
      #   # with app_mounted_at = '/blog'
      #   path_app(:path)     => '/blog/path'
      # 
      def path_app(path='/') 
        path = path.nil? ? '/' : path
        path = (path.to_s[0,1] == '/') ? path : "/#{path}"
        "#{self.class.app_mounted_at}#{path}"
      end
      
    end #/ Helpers
    
    def self.registered(app)
      app.helpers MountedAtExample::Helpers
      
      app.set :app_mounted_at, '/'
    end
    
  end #/ MountedAtExample
end #/ Sinatra


## This is a free standing App
class MyApp < Sinatra::Base 
  register(Sinatra::MountedAtExample)
  
  set :public, "#{APP_ROOT}/public"
  set :views, "#{APP_ROOT}/views"
  
  get '/' do
    @html ||= "Hello from MyApp"
    %Q{
    <p>#{@html},  I'm mounted at [#{self.class.app_mounted_at}]</p>
    <p>Checkout My<a href=/blog/>Blog</a> as well</p>
    <p>or My<a href=/gallery/>Gallery</a>instead</p>
    }
  end
  
  get '/another-page' do
    %Q{Great!! It works  <br>Back to  <a href="#{path_app}" title="link to home">MyApp Home</a>}
  end
  
end #/class MyApp


module MyComplexApp
  
  class App < Sinatra::Base
    register(Sinatra::MountedAtExample)   # sets the app_mounted_at for all instances of App
    
    set :views, "views"
    
    get '/' do
      %Q{
        <p>#{self.class.name} is mounted at [#{self.class.app_mounted_at}] </p>
      }
    end
    
    # just dumps the available methods of MyApp, so that you can easily see the routes defined
    get '/methods' do
      "#{self.methods.sort.join(",\n<br>")}"
    end
    
  end
  
  class Blog < App
    
    set :views, "views/blog"
    
    get '/' do
      %Q{<p>hello from the Blog (mounted at [#{self.class.app_mounted_at}])</p>
      <p>read some <a href="#{path_app(:articles)}" title="link to articles">articles</a></p>
      <p>or go back to <a href="/" title="link to MyApp">MyApp</a></p>
      }
    end
     
    get '/articles' do
      %Q{Great!! It works  <br>Back to  <a href="#{path_app}" title="link to home">Blog Home</a>}
    end
    
  end #/class Blog
    
  # class Gallery < Sinatra::Base
  class Gallery < App 
    
    get '/' do
      %Q{
      <p>hello from the Gallery (mounted at [#{self.class.app_mounted_at}])</p>
      <p>view some <a href="#{path_app(:pictures)}" title="link to pictures">pictures</a></p>
      <p>or go back to <a href="/" title="link to MyApp">MyApp</a></p>
      }
    end
    
    get '/pictures' do
      %Q{Great!! It works as well <br>Back to  <a href="#{path_app}" title="link to home">Gallery Home</a> }
    end
  end #/ Gallery
  
end #/module MyComplexApp

map "/gallery" do
  MyComplexApp::Gallery.app_mounted_at = '/gallery'
  run MyComplexApp::Gallery
end

map "/blog" do
  MyComplexApp::Blog.app_mounted_at = '/blog'
  run MyComplexApp::Blog
end

map "/" do
  MyApp.app_mounted_at = '/'  # no need it's working anyway
  run MyApp
end


##  Just an example of how you can create a base app and then just extend it with

class ExtendedApp < MyApp
  
  get '/' do
    # crude way of showing that you can override some value and then just load the page 
    @html = "Greetings from ExtendedApp"
    super
  end
end

map "/extended" do
  ExtendedApp.app_mounted_at = '/extended'
  run ExtendedApp
end