Padrino (padrino-core)

Padrino is the godfather of Sinatra.

Preface

Padrino is a ruby framework built upon the excellent Sinatra Microframework. Sinatra is a DSL for creating simple web applications in Ruby with speed and minimal effort. This framework tries hard to make it as fun and easy as possible to code much more advanced web applications by building upon the Sinatra philosophies and foundation.

Introduction

Many people love Sinatra’s simplicity and lightweight but often quickly come to miss a great deal of functionality provided by other web frameworks such as Rails when building non-trivial applications.

Our goal with this framework is to match the essence of Sinatra and at the same time create a standard library of tools, helpers and components that will make Sinatra suitable for more complex applications.

Here is a brief overview of functionality provided by the Padrino framework:

Agnostic: Full support for many popular testing, templating, mocking, and data storage choices.
Generators: Create Padrino applications, models, controllers i.e: padrino-gen project.
Mountable: Unlike other ruby frameworks, principally designed for mounting multiple apps.
Routing: Full url named routes, named params, before/after filter support.
Tag Helpers: View helpers such as: tag, content_tag, input_tag.
Asset Helpers: View helpers such as: link_to, image_tag, javascript_include_tag.
Form Helpers: Builder support such as: form_tag, form_for, field_set_tag, text_field.
Text Helpers: Useful formatting like: time_ago_in_words, js_escape_html, sanitize_html.
Mailer: Fast and simple delivery support for sending emails (akin to ActionMailer).
Admin: Builtin Admin interface (like Django)
Logging: Provide a unified logger that can interact with your ORM or any library.
Reloading: Automatically reloads server code during development.
Localization: Full support of I18n language localization and can auto-set user’s locale.

Keep in mind, the user will be able to pull in these components seperately into existing Sinatra applications or use them altogether for a comprehensive upgrade to Sinatra (a full-stack Padrino application).

Installation

To install the padrino framework, simply grab the latest version from gemcutter:

$ sudo gem install padrino

This will install the necessary padrino gems to get you started. Now you are ready to use this gem to enhance your sinatra projects or to create new Padrino applications.

For a more detailed look at Padrino installation, check out the Installation Guide.

Usage

Padrino is a framework which builds on the existing functionality and Sinatra and provides a variety of additional tools and helpers to build upon that foundation. This README and Padrino documentation in general will focus on the enhancements to the core Sinatra functionality. To use Padrino, one should be familiar with the basic usage of Sinatra itself.

Please check out the Understanding Sinatra guide to learn more about these fundamentals.

For information on how to use a specific gem in isolation within an existing Sinatra project, checkout the guide for Using Padrino in Sinatra.

Getting Started

Once a developer understands Sinatra, Padrino is quite easy to get comfortable with since Padrino is simply a superset of existing Sinatra Functionality! Best way to get started with building Padrino applications is to read following resources:

Blog Tutorial - Step-by-step guide to building a blog application with Padrino.
Quick Overview - Outlines basic generation commands.
Padrino Examples - List of known Padrino applications which can serve as examples.

Enhanced Base Application (padrino-core)

Sinatra has support for classes which can be extended to create an application: Sinatra::Base and Sinatra::Application These classes can be extended in order to create a Sinatra web application. These classes provide support for all the basic functionality afforded by Sinatra.

Padrino has support for an enhanced base application class Padrino::Application. Padrino::Application expands the capabilities of Sinatra::Application and automatically provides the resulting application access to all of the padrino framework’s functionalities.

Simple Application Definition

Let us first take a look at the simplest possible Padrino application:

# app.rb
PADRINO_ROOT = File.dirname(__FILE__) unless defined? PADRINO_ROOT
require 'padrino'
Padrino.load!

class SimpleApp < Padrino::Application
  get '/' do
    'Hello world'
  end

  # and for read better we can divide with controllers
  controller '/admin' do
    get '/foo' do
      'Url is /admin/foo'
    end
  end
end

For a complete overview of the Padrino routing and controller system, check out the Routing and Controller guide.

Enhanced Route Definitions and Controllers

Suppose we wanted to add additional routes to our Padrino application, and we want to organize the routes within a more structured layout. Simply add a controllers or app/controllers folder and create a file as such:

# Simple Example
SimpleApp.controllers do
  get "/test" do
    "Text to return"
  end
end

You can also do more complex route alias definitions:

# app/controllers/example.rb
SimpleApp.controllers :posts do
  get :index do
    ...
  end

  get :show, :with => :id do
    # url generated is '/posts/show/:id'
    # access params[:id]
  end
end

as well as mapping the route aliases to an explicit url:

# app/controllers/example.rb
SimpleApp.controllers do
  get :index, :map => '/index' do
    ...
  end

  get :account, :map => '/the/accounts/:name/and/:id' do
    # access params[:name] and params[:index]
  end
end

and even configure the provides for each route:

# app/controllers/example.rb
SimpleApp.controllers :admin do
  get :show, :with => :id, :provides => :js do
    "Url is /admin/show/#{params[:id]}.#{params[:format]}"
  end

  get :other, :with => [:id, :name], :provides => [:html, :json] do
    case content_type
      when :js    then ... end
      when :json  then ... end
    end
  end
end

or auto lookup for current locale or content_type

# app/controllers/example.rb
SimpleApp.controllers :admin do
  get :show, :with => :id, :provides => [:html, :js] do
    render "admin/show"
  end
end

When you visit :show and your I18n.locale == :ru Padrino try to look for “admin/show.ru.js.*” if nothing match that path they try “admin/show.ru.*” then “admin/show.js.*” if none match return “admin/show.erb” (or other engine i.e. haml)

For a complete overview of the routing and controller system, check out the Routing and Controller guide.

Rendering

Unlike Sinatra, Padrino supports automatic template lookups such as:

# searches for 'account/index.{erb,haml,...}
render 'account/index'

This render does not require any template engine to be specified and will choose the first one that is discovered. The existing render function works as well if an engine type should be specified:

# example.haml render :haml, ‘account/index’

For a complete overview of the Padrino rendering system, check out the Routing and Controller guide.

Layout

With Padrino you can (like rails do) use for your custom layout, disable it

class SimpleApp < Padrino::Application

  # Disable layouts
  disable layout

  # Use the layout located in views/layouts/custom.haml
  layout :custom

For a complete overview of the layout functionality, check out the Routing and Controller guide.

Mounting Applications

Padrino applications are all automatically mountable into other Padrino projects. This means that a given Padrino project directory can easily mount multiple applications. This allows for better organization of complex applications, re-usable applications that can be applied (i.e admin, auth, blog) and even more flexibility.

You can think of mountable applications as a ‘full-featured’ merb slice or rails engine. Instead of a separate construct, any application can simply be packaged and mounted into another project.

Padrino stores application mounting information by default within config/apps.rb. This file is intended to keep all information regarding what applications are mounted to which uri’s.

For a complete look at mounting applications within a Padrino project, check out the guide on Mounting Applications.

Auto Load Paths

Padrino also intelligently supports requiring useful files within your application automatically and provides functionality for easily splitting up your application into separate files. Padrino automatically requires config/database.rb as a convention for establishing database connection. Also, any files within the lib folder will be required automatically by Padrino.

For a complete overview of auto-loaded paths within Padrino, check out the Padrino Development Guide.

Application Logging

Padrino also supports robust logging capabilities. By default, logging information will go to the STDOUT in development (for use in a console) and in an environment-specific log file log/development.log in test and production environments.

To use the logger within a Padrino application, simply refer to the logger method accessible within your app and any controller or views:

# controllers/example.rb
SimpleApp.controllers do
  get("/test") { logger.info "This is a test" }
end

For a complete overview of Padrino logger functionality, check out the Padrino Development Guide.

Development Reloader

Padrino applications also have the enabled ability to automatically reload all changing application files without the need to restart the server. Through the use of a customized Rack middleware, all files on the ‘load path’ are monitored and reloaded whenever changes are applied.

This makes rapid development much easier and provides a better alternative to ‘shotgun’ or ‘rerun’ which requires the application server to be restarted which makes requests take much longer to complete.

For a complete overview of code reloading in development, check out the Padrino Development Guide.

Terminal Commands

Padrino also comes equipped with multiple useful terminal commands which can be activated to perform common tasks such as starting / stopping the application, executing the unit tests or activating an irb session.

The following commands are available:

# starts the app server (non-daemonized)
$ padrino start
# starts the app server (daemonized) with given port, environment and adapter
$ padrino start -d -p 3000 -e development -a thin

# Stops a daemonized app server
$ padrino stop

# Bootup the Padrino console (irb)
$ padrino console

# Run/List tasks
$ padrino rake

You can also create custom rake tasks as well. Using these commands can simplify common tasks making development that much smoother.

For a complete overview of Padrino terminal commands, check out the Padrino Commands Guide.