EM-HTTP-Client¶ ↑

EventMachine based HTTP Request interface. Supports streaming response processing, uses Ragel HTTP parser.

• Simple interface for single & parallel requests via deferred callbacks

• Automatic gzip & deflate decoding

• Basic-Auth & OAuth support

• Custom timeouts

• Proxy support (with SSL Tunneling)

• Bi-directional communication with web-socket services

Screencast / Demo of using EM-HTTP-Request:

• everburning.com/news/eventmachine-screencast-em-http-request/

Getting started¶ ↑

# install & configure gemcutter repos
gem update --system
gem install gemcutter
gem tumble

gem install em-http-request

irb:0> require 'em-http'

Simple client example¶ ↑

EventMachine.run {
  http = EventMachine::HttpRequest.new('http://127.0.0.1/').get :query => {'keyname' => 'value'}, :timeout => 10

  http.callback {
    p http.response_header.status
    p http.response_header
    p http.response

    EventMachine.stop
  }
}

Multi request example¶ ↑

Fire and wait for multiple requess to complete via the MultiRequest interface.

EventMachine.run {
  multi = EventMachine::MultiRequest.new

  # add multiple requests to the multi-handler
  multi.add(EventMachine::HttpRequest.new('http://www.google.com/').get)
  multi.add(EventMachine::HttpRequest.new('http://www.yahoo.com/').get)

  multi.callback  {
    p multi.responses[:succeeded]
    p multi.responses[:failed]

    EventMachine.stop
  }
}

Basic-Auth example¶ ↑

Full basic author support. For OAuth, check examples/oauth-tweet.rb file.

EventMachine.run {
  http = EventMachine::HttpRequest.new('http://www.website.com/').get :head => {'authorization' => ['user', 'pass']}

  http.errback { failed }
  http.callback {
    p http.response_header
    EventMachine.stop
  }
}

POST example¶ ↑

EventMachine.run {
  http1 = EventMachine::HttpRequest.new('http://www.website.com/').post :body => {"key1" => 1, "key2" => [2,3]}
  http2 = EventMachine::HttpRequest.new('http://www.website.com/').post :body => "some data"

  # ...
}

Streaming body processing¶ ↑

Allows you to consume an HTTP stream of content in real-time. Each time a new piece of conent is pushed to the client, it is passed to the stream callback for you to operate on.

EventMachine.run {
  http = EventMachine::HttpRequest.new('http://www.website.com/').get
  http.stream { |chunk| print chunk }

  # ...
}

Proxy example¶ ↑

Full transparent proxy support with support for SSL tunneling.

EventMachine.run {
  http = EventMachine::HttpRequest.new('http://www.website.com/').get :proxy => {
    :host => 'www.myproxy.com',
    :port => 8080,
    :authorization => ['username', 'password'] # authorization is optional
}

WebSocket example¶ ↑

Bi-directional communication with WebSockets: simply pass in a ws:// resource and the client will negotiate the connection upgrade for you. On successfull handshake the callback is invoked, and any incoming messages will be passed to the stream callback. The client can also send data to the server at will by calling the “send” method!

• www.igvita.com/2009/12/22/ruby-websockets-tcp-for-the-browser/

  EventMachine.run {

  http = EventMachine::HttpRequest.new("ws://yourservice.com/websocket").get :timeout => 0
  
  http.errback { puts "oops" }
  http.callback {
    puts "WebSocket connected!"
    http.send("Hello client")
  }
  
  http.stream { |msg|
    puts "Recieved: #{msg}"
    http.send "Pong: #{msg}"
  }
  

  }