= Sinatra

Sinatra is a DSL for quickly creating web-applications in Ruby with minimal
effort.

== Sample App

  # myapp.rb
  require 'rubygems'
  require 'sinatra'
  get '/' do
    'Hello world!'
  end

Run with <tt>ruby myapp.rb</tt> and view at <tt>http://localhost:4567</tt>

== HTTP Methods

  get '/' do
    .. show things ..
  end

  post '/' do
    .. create something ..
  end

  put '/' do
    .. update something ..
  end

  delete '/' do
    .. annihilate something ..
  end

  head '/' do

  end

NOTE: <tt>put</tt> and <tt>delete</tt> are also triggered when a
<tt>_method</tt> parameter is set to PUT or DELETE and the HTTP request method
is POST

== Routes

Routes are matched based on the order of declaration. The first route that
matches the request is invoked.

Simple:

  get '/hi' do
    ...
  end

Named parameters:

  get '/:name' do
    # matches /sinatra and the like and sets params[:name]
  end

Splat parameters:

  get '/say/*/to/*' do
    # matches /say/hello/to/world
    params["splat"] # => ["hello", "world"]
  end

  get '/download/*.*' do
    # matches /download/path/to/file.xml
    params["splat"] # => ["path/to/file", "xml"]
  end

User agent matching:

  get '/foo', :agent => /Songbird (\d\.\d)[\d\/]*?/ do
    "You're using Songbird version #{params[:agent][0]}"
  end

  get '/foo' do
    # matches non-songbird browsers
  end

== Static files

Put all of your static content in the ./public directory

  root
    \ public

If a file exists that maps to the REQUEST_PATH then it is served and the
request ends. Otherwise, Sinatra will look for an event that matches the
path.

== Views

Views are searched for in a "views" directory in the same location as
your main application.

=== Haml Templates

  get '/' do
    haml :index
  end

Renders <tt>./views/index.haml</tt>.

=== Erb

  get '/' do
    erb :index
  end

Renders <tt>./views/index.erb</tt>

=== Builder

See Sinatra::Builder

=== Sass

  get '/stylesheet.css' do
    content_type 'text/css', :charset => 'utf-8'
    sass :stylesheet
  end

Renders <tt>./views/stylesheet.sass</tt>.

=== Inline Templates

  get '/' do
    haml '%div.title Hello World'
  end

Renders the inlined template string.

=== Accessing Variables

Templates are evaluated within the Sinatra::EventContext instance
used to evaluate event blocks. Instance variables set in event
blocks can be accessed direcly in views:

  get '/:id' do
    @foo = Foo.find(params[:id])
    haml '%h1== @foo.name'
  end

Or, specify an explicit Hash of local variables:

  get '/:id' do
    foo = Foo.find(params[:id])
    haml '%h1== foo.name', :locals => { :foo => foo }
  end

This is typically used when rendering templates as partials from within
other templates.

=== In-file Templates

Templates may be defined at the end of the source file:

  get '/' do
    haml :index
  end

  use_in_file_templates!

  __END__

  @@ layout
  X
  = yield
  X

  @@ index
  %div.title Hello world!!!!!

It's also possible to define named templates using the top-level template
method:

  template :layout do
    "X\n=yield\nX"
  end

  template :index do
    '%div.title Hello World!'
  end

  get '/' do
    haml :index
  end

== Helpers

The top-level <tt>helpers</tt> method takes a block and extends all
EventContext instances with the methods defined:

  helpers do
    def bar(name)
      "#{name}bar"
    end
  end

  get '/:name' do
    bar(params[:name])
  end

== Filters

These are run in Sinatra::EventContext before every event.

  before do
    .. this code will run before each event ..
  end

== Halt!

To immediately stop a request during a before filter or event use:

  throw :halt

Set the body to the result of a helper method

  throw :halt, :helper_method

Set the body to the result of a helper method after sending it parameters from
the local scope

  throw :halt, [:helper_method, foo, bar]

Set the body to a simple string

  throw :halt, 'this will be the body'

Set status then the body

  throw :halt, [401, 'go away!']

Set the status then call a helper method with params from local scope

  throw :halt, [401, [:helper_method, foo, bar]]

Run a proc inside the Sinatra::EventContext instance and set the body to the
result

  throw :halt, lambda { puts 'In a proc!'; 'I just wrote to $stdout!' }

Create you own to_result

  class MyResultObject
    def to_result(event_context, *args)
      event_context.body = 'This will be the body!
    end
  end

  get '/' do
    throw :halt, MyResultObject.new
  end

Get the gist?  If you want more fun with this then checkout <tt>to_result</tt>
on Array, Symbol, Fixnum, NilClass.

== Configuration and Reloading

Sinatra supports multiple environments and reloading. Reloading happens
before every request when running under the :development environment. Wrap
your configurations in <tt>configure</tt> (i.e. Database connections, Constants,
etc.) to protect them from reloading or to target specific environments.

All environments:

  configure do
    ...
  end

Production:

  configure :production do
    ...
  end

Two at a time:

  configure :production, :test do
    ...
  end

This is also really nifty for error handling.

== Error handling

Error handlers run inside the current Sinatra::EventContext instance, which
means you get all the goodies it has to offer (i.e. haml, erb, throw :halt,
etc.)

=== Not Found

When Sinatra::NotFound is raised, the not_found handler is invoked:

  not_found do
    'This is nowhere to be found'
  end

=== Error

By default, the +error+ handler is invoked on Sinatra::ServerError or when
an unknown error occurs.

The exception can be obtained from the 'sinatra.error' variable in
request.env.

  error do
    'Sorry there was a nasty error - ' + request.env['sinatra.error'].name
  end

Custom errors:

  error MyCustomError do
    'So what happened was...' + request.env['sinatra.error'].message
  end

Then, if this happens:

  get '/' do
    raise MyCustomError, 'something bad'
  end

You get this:

  So what happened was... something bad

Sinatra installs special not_found and error handlers when running under
the development.

== Mime types

When using send_file or static files you may have mime types Sinatra doesn't
understand.  Use +mime+ in those cases.

  mime :foo, 'text/foo'

== Rack Middleware

Sinatra rides on Rack[http://rack.rubyforge.org/], a minimal standard
interface for Ruby web frameworks. One of Rack's most interesting capabilities
for application developers is support for "middleware" -- components that sit
between the server and your application monitoring and/or manipulating the
HTTP request/response to provide various types of common functionality.

Sinatra makes building Rack middleware pipelines a cinch via a top-level
+use+ method:

  require 'sinatra'
  require 'my_custom_middleware'

  use Rack::Lint
  use MyCustomMiddleware

  get '/hello' do
    'Hello World'
  end

The semantics of +use+ are identical to those defined for the
Rack::Builder[http://rack.rubyforge.org/doc/classes/Rack/Builder.html] DSL
(most frequently used from rackup files). For example, the +use+ method
accepts multiple/variable args as well as blocks:

  use Rack::Auth::Basic do |username, password|
    username == 'admin' && password == 'secret'
  end

Rack is distributed with a variety of standard middleware for logging,
debugging, URL routing, authentication, and session handling. Sinatra uses
many of of these components automatically based on configuration so you
typically don't have to +use+ them explicitly.

== Testing

=== Test/Unit

  require 'rubygems'
  require 'sinatra'
  require 'sinatra/test/unit'
  require 'my_sinatra_app'

  class MyAppTest < Test::Unit::TestCase

    def test_my_default
      get_it '/'
      assert_equal 'My Default Page!', @response.body
    end

    def test_with_agent
      get_it '/', :agent => 'Songbird'
      assert_equal 'You're in Songbird!', @response.body
    end

    ...

  end

=== Specs

  require 'rubygems'
  require 'sinatra'
  require 'sinatra/test/spec'
  require 'my_sinatra_app'

  describe 'My app' do

    it "should show a default page" do
      get_it '/'
      should.be.ok
      body.should.equal 'My Default Page!'
    end
    ...

  end

See Sinatra::Test::Methods for more information on +get_it+, +post_it+,
+put_it+, and friends.

== Command line

Sinatra applications can be run directly:

  ruby myapp.rb [-h] [-x] [-p PORT] [-e ENVIRONMENT]

Options are:

  -h # help
  -p # set the port (default is 4567)
  -e # set the environment (default is development)
  -x # turn on the mutex lock (default is off)

== Contributing

=== Tools

Besides Ruby itself, you only need a text editor, preferably one that supports
Ruby syntax hilighting. VIM and Emacs are a fine choice on any platform, but
feel free to use whatever you're familiar with.

Sinatra uses the Git source code management system. If you're unfamiliar with
Git, you can find more information and tutorials on http://git.or.cz/ as well
as http://git-scm.com/.  Scott Chacon created a great series of introductory
screencasts about Git, which you can find here: http://www.gitcasts.com/

=== First Time: Cloning The Sinatra Repo

  cd where/you/keep/your/projects
  git clone git://github.com/bmizerany/sinatra.git
  cd sinatra
  cd path/to/your_project
  ln -s ../sinatra/

=== Updating Your Existing Sinatra Clone

  cd where/you/keep/sinatra
  git pull

=== Using Edge Sinatra in Your App

at the top of your sinatra_app.rb file:

  $:.unshift File.dirname(__FILE__) + '/sinatra/lib'
  require 'sinatra'

  get '/about' do
    "I'm running on Version " + Sinatra::VERSION
  end

=== Contributing a Patch

There are several ways to do this. Probably the easiest (and preferred) way is
to fork Sinatra on GitHub (http://github.com/bmizerany/sinatra), push your
changes to your Sinatra repo, and then send Blake Mizerany (bmizerany on
GitHub) a pull request.

You can also create a patch file and attach it to a feature request or bug fix
on the issue tracker (see below) or send it to the mailing list (see Community
section).

=== Issue Tracking and Feature Requests

http://sinatra.lighthouseapp.com/

== Community

=== Mailing List

http://groups.google.com/group/sinatrarb

If you have a problem or question, please make sure to include all the
relevant information in your mail, like the Sinatra version you're using, what
version of Ruby you have, and so on.

=== IRC Channel

You can find us on the Freenode network in the channel #sinatra
(irc://chat.freenode.net/#sinatra)

There's usually someone online at any given time, but we cannot pay attention
to the channel all the time, so please stick around for a while after asking a
question.