MerbAn Introduction

Who am I?

History

Key Focus

Fast(No code is faster than no code)

Memory Efficient

Modular(All you need none you don’t)

As Simple As Possible

Features

Plugins as Gems

Rack Integration

uploader = Proc.new do |env| request = Merb::Request.new(env) if request.path =~ /\/images\/upload/ params = request.params FileUtils.mv params[:file][:tempfile].path, Merb.root / 'public' / 'uploads' / params[:file][:filename]

headers = {"Content-Type"=>"text/html", "Location" => "/images"} [302, headers, "You are being redirected"] else [404, {}, "No Upload here, move along"] end end

merb = Merb::Rack::Application.new

run Rack::Cascade.new([uploader, merb])

File upload example using rack middleware

Router

Optional Path SegmentsMatching match("/articles(/:year(/:month(/:day)))/:title"). to(:controller => "articles", :action => "show"). name(:article) Generating /articles/Hello => { :title => “Hello” } /articles/2008/07/Hello => { :year => “2008”, :month => “07”, :title => “Hello” }

Access to Request & Params

match("/secret").defer_to do |request, params| if request.session.authenticated? params end end

http://www.slideshare.net/carllerche/merb-pluming-the-router-presentation

Controllers

class Posts < Application provides :xml def show @post = Post.get(params[:id]) display @post end end

Background Processing

render_then_call dosend_notification

end

run_later do send_notificationend

Exceptions

class Exceptions < Merb::Controller # handle NotFound exceptions (404) def not_found render :format => :html end

# handle NotAcceptable exceptions (406) def not_acceptable render :format => :html end

end

Merb Slice

Application Server

merb -e produciton -d -c 4

kill HUP ‘master process id’

Processes• master• spawner• worker

Hot Deploy

Questions?