And the Greatest of These Is ... Rack Support

And the Greatest of These Is... Rack Support Ben Sco eld – Viget Labs

#?forben

Application Templates

Nested Attribute Assignment ickr: angelrays

ActiveRecord::Base#touch ickr: jjjohn

def call(env) [ status, # 200 headers, # {quot;Content-Typequot; => quot;text/htmlquot;} body # [quot;<html>...</html>quot;] ] end

request application response

request middleware application middleware response

Rack::Pro ler ickr: oberazzi

Rack::MailExceptions ickr: warmnfuzzy

Rack::Cache ickr: timpatterson

rack::cascade Rack::Cascade ickr: _at

Rack in Rails

> rake middleware use Rack::Lock use ActionDispatch::Failsafe use ActionDispatch::ShowExceptions, [true] use ActionDispatch::Rescue, [#<Method: ...>] use ActionDispatch::Session::CookieStore, [{...}] use ActionDispatch::ParamsParser use Rack::MethodOverride use Rack::Head use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache run ActionController::Dispatcher.new

app = Rack::Builder.new { use Rails::Rack::LogTailer unless options[:detach] use Rails::Rack::Debugger if options[:debugger] map quot;/quot; do use Rails::Rack::Static run ActionController::Dispatcher.new end }.to_app

Rails::Initializer.run do |config| config.middleware.insert_before Rack::Head, Ben::Asplode config.middleware.swap Rack::Lock, Ben::Lock config.middleware.use Rack::MailExceptions end

Metal ickr: lrargerich

http://www.kiwibean.com/

PLEASE testing metalBY STAND EXPAND: THIS IS ONLY A TEST

METAL Sinatra

Cool Tricks

Rack::Bug ickr: catdancing

requires </body>

Progressive Caching

class SessionsController < ApplicationController def create # ... session[:personalize] = { :logged_in => true, :quicklist => current_user.quicklist.episode_ids, :subscriptions => current_user.subscription_ids } end end

class ChannelsController < ApplicationController caches_page :show def show @channel = Channel.ﬁnd(params[:id]) end end

$(document).ready(function() { $.getJSON('/personalize', function(data) { // identify quicklisted episodes $.each(data['quicklist'], function() { $('#episode_'+this).addClass('listed'); }); // switch navigation if (data['logged_in']) { $('#logged_in_nav').show(); } // etc. }); });

class Personalizer def self.call(env) if env[quot;PATH_INFOquot;] =~ /^/personalize/ [ 200, {quot;Content-Typequot; => quot;application/javascriptquot;}, env['rack.session'][:personalize].to_json ] else [404, {quot;Content-Typequot; => quot;text/htmlquot;}, [quot;Not Foundquot;]] end end end

class PullList def self.call(env) if env[quot;PATH_INFOquot;] =~ /^/pulls/ [ 200, {quot;Content-Typequot; => quot;application/javascriptquot;}, [Pull.by_user(user).for_date(date).map {|i| i.item_id}.to_json]] else [404, {quot;Content-Typequot; => quot;text/htmlquot;}, [quot;Not Foundquot;]] end end end standard 0.617 progressive 0.039 0.096

class PullList def self.call(env) if env[quot;PATH_INFOquot;] =~ /^/pulls/ [ 200, {quot;Content-Typequot; => quot;application/javascriptquot;}, [env['rack.session'][:pulls].to_json] ] else [404, {quot;Content-Typequot; => quot;text/htmlquot;}, [quot;Not Foundquot;]] end end end standard 0.617 progressive 0.039 0.096 progressive v2 0.043 0.023

request middleware application middleware response

Rack::Embiggener

class Embiggener < Test::Unit::TestCase def test_embiggener_should_embiggen_known_url body = [quot;Hello! I'm at http://tinyurl.com/cjmhvaquot;] assert_equal [quot;Hello! I'm at http://www.culann.comquot;], Rack:: Embiggener.embiggen_urls(body) end def test_embiggener_should_embiggen_multiple_urls body = [ quot;Hello! I'm at http://tinyurl.com/cjmhvaquot;, quot;And I'm at http://tinyurl.com/cjmhvaquot; ] assert_equal [ quot;Hello! I'm at http://www.culann.comquot;, quot;And I'm at http://www.culann.comquot; ], Rack::Embiggener.embiggen_urls(body) end end

module Rack class Embiggener def self.embiggen_urls(original_body) new_body = [] original_body.each { |line| tinys = line.scan(/(http://(?:www.)?tinyurl.com/(.{6}))/) new_body << tinys.uniq.inject(line) do |body, tiny| original_tiny = tiny[0] preview_url = quot;http://preview.tinyurl.com/#{tiny[1]}quot; response = Net::HTTP.get_response(URI.parse(preview_url)) embiggened_url = response.body.match(/redirecturlquot; href=quot;(.*)quot;>/)[1] body.gsub(original_tiny, embiggened_url) end } new_body end # ... end end

module Rack class Embiggener # ... def initialize(app) @app = app end def call(env) status, headers, body = @app.call(env) headers.delete('Content-Length') response = Rack::Response.new( Rack::Embiggener.embiggen_urls(body), status, headers ) response.ﬁnish return response.to_a end end end

WARNING exception handling

formerly: WARNING exception handling

Rack::Hoptoad* * unoﬃcial; thoughtbot is not responsible for this middleware; do not taunt rack::hoptoad; pregnant women should consult their doctors before using rack::hoptoad

> rake middleware use Rack::Lock use ActionDispatch::Failsafe use ActionDispatch::ShowExceptions, [true] use ActionDispatch::Rescue, [#<Method: ...>] use ActionDispatch::Session::CookieStore, [{...}] use ActionDispatch::ParamsParser use Rack::MethodOverride use Rack::Head use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache run ActionController::Dispatcher.new

Rails::Initializer.run do |config| # ... config.middleware.delete ActionDispatch::ShowExceptions config.middleware.delete ActionDispatch::Rescue config.middleware.use 'Rack::Hoptoad', 'my-hoptoad-api-key' config.middleware.use 'Rack::ShowExceptions' end

module Rack class Hoptoad def initialize(app, api_key) @app = app @api_key = api_key end def call(env) @app.call(env) rescue => exception notify_hoptoad(exception, env) raise exception end # ... end end

module Rack class Hoptoad def notify_hoptoad(exception, env) headers = { 'Content-type' => 'application/x-yaml', 'Accept' => 'text/xml, application/xml' } url = URI.parse(quot;http://hoptoadapp.com/noticesquot;) http = Net::HTTP.new(url.host, url.port) data = { :api_key => @api_key, :error_message => quot;#{exception.class}: #{exception}quot;, :backtrace => exception.backtrace, :request => {}, :session => env['rack.session'], :environment => env } response = http.post( url.path, stringify_keys(:notice => data).to_yaml, headers ) if response != Net::HTTPSuccess # Hoptoad post failed end end end end

Intangibles

Thank You ben sco eld - @bsco eld - http://www.viget.com/extend - http://www.speakerrate.com/bsco eld

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And the Greatest of These Is ... Rack Support

by Ben Scofield on May 07, 2009

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