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sinatra/README.rdoc
2009-01-09 16:27:02 -08:00

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= 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
== Routes
Routes are matched based on the order of declaration. The first route that
matches the request is invoked.
Basic routes:
get '/hi' do
...
end
Named parameters:
get '/:name' do
# matches "GET /foo" and "GET /bar"
# params[:name] is 'foo' or 'bar'
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
To use a different static directory:
set :public, File.dirname(__FILE__) + '/static'
== Views
Views are searched for in a ./views directory in the same location as
your main application.
To use a different views directory:
set :views, File.dirname(__FILE__) + '/templates'
=== 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
Some times you'll want to render a specific template with or without a
layout (i.e. if a request is Ajax or not).
get '/' do
haml :index, :layout => !request.xhr?
end
== Helpers
The top-level <tt>helpers</tt> method
helpers do
def bar(name)
"#{name}bar"
end
end
get '/:name' do
bar(params[:name])
end
== Filters
Before filters are evaluated in request context before routing is performed:
before do
@note = 'Hi!'
request.path_info = '/foo/bar/baz'
end
get '/foo/*' do
@note #=> 'Hi!'
params[:splat] #=> 'bar/baz'
end
Before filters can modify the request and response; instance variables are
available to routes.
== Halt!
To immediately stop a request during a before filter or event use:
throw :halt
Set the body to a simple string
throw :halt, 'this will be the body'
Set status then the body
throw :halt, [401, 'go away!']
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!' }
== 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
=== Test/Spec
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
=== RSpec
require 'rubygems'
require 'spec'
require 'sinatra'
require 'sinatra/test/rspec'
require 'my_sinatra_app'
describe 'My app' do
it 'should show a default page' do
get_it '/'
@response.should be_ok
@response.body.should == '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.