playful

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Status

Description

Ruby's UPnP RubyGem was outdated in Ruby 1.9 when support for Soap4r was dropped. This gem intends to fill that void for Ruby >= 1.9 and allow for SSDP search, discovery, advertisement, the ability to act as a UPnP control point, as well as provide UPnP devices and services.

This uses EventMachine, so if you're not already, getting familiar with its concepts will be helpful here.

Er, what's UPnP??

"Universal Plug and Play" is a mashup of network protocols that let network devices identify themselves and discover and use each other's services. Common implementations of UPnP devices are things like:

If you have a device that implements UPnP, you can most likely control it programmatically with playful. You can't today, but eventually you'll be able to build your own devices & services with playful that can be consumed by other UPnP clients (ex. build a media server with playful and listen on your PS3...).

Features

Implemented

  • SSDP search, discovery. (almost settled down)
  • Ability to act as a UPnP Control Point. (in progress)
  • Rack middleware to allow for device access in a Rack app.

Coming

  • UPnP Devices & Services (server)

Examples

Take a look at the tasks directory; I've created some working examples using Thor. You can get a list of these tasks by doing thor -T.

There's also a more involved, in-progress, working example at http://github.com/turboladen/upnp_cp_on_sinatra that uses the Rack middleware to build a Sinatra app that allows for controling devices in your network.

SSDP Searches

An SSDP search simply sends the M-SEARCH out to the multicast group and listens for responses for a given (or default of 5 seconds) amount of time. The return from this depends on if you're running it within an EventMachine reactor or not. If not, it returns is an Array of responses as Hashes, where keys are the header names, values are the header values. Take a look at the SSDP.search docs for more on the options here.

require 'playful/ssdp'

# Search for all devices (do an M-SEARCH with the ST header set to 'ssdp:all')
all_devices = Playful::SSDP.search                         # this is default
all_devices = Playful::SSDP.search 'ssdp:all'              # or be explicit
all_devices = Playful::SSDP.search :all                    # or use short-hand

# Search for root devices (do an M-SEARCH with ST header set to 'upnp:rootdevices')
root_devices = Playful::SSDP.search 'upnp:rootdevices'
root_devices = Playful::SSDP.search :root                  # or use short-hand

# Search for a device with a specific UUID
my_device = Playful::SSDP.search 'uuid:3c202906-992d-3f0f-b94c-90e1902a136d'

# Search for devices of a specific type
my_media_server = Playful::SSDP.search 'urn:schemas-upnp-org:device:MediaServer:1'

# All of these searches will return something that looks like
# => [
#      {
#         :control => "max-age=1200",
#         :date => "Sun, 23 Sep 2012 20:31:48 GMT",
#         :location => "http://192.168.10.3:5001/description/fetch",
#         :server => "Linux-i386-2.6.38-15-generic-pae, UPnP/1.0, PMS/1.50.0",
#         :st => "upnp:rootdevice",
#         :ext => "",
#         :usn => "uuid:3c202906-992d-3f0f-b94c-90e1902a136d::upnp:rootdevice",
#         :length => "0"
#       }
#     ]

If you do the search inside of an EventMachine reactor, as the Playful::SSDP::Searcher receives and parses responses, it adds them to the accessor #discovery_responses, which is an EventMachine::Channel. This lets you subscribe to the resposnes and do what you want with them (most likely you'll want to create Playful::ControlPoint::Device objects so you can control your device) as you receive them.

require 'playful/ssdp'
require 'playful/control_point/device'

EM.run do
  searcher = Playful::SSDP.search 'uuid:3c202906-992d-3f0f-b94c-90e1902a136d'

  # Create a deferrable object that can be notified when the device we want
  # has been found and created.
  device_controller = EventMachine::DefaultDeferrable.new

  # This callback will get called when the device_creator callback is called
  # (which is called after the device has been created).
  device_controller.callback do |device|
    p device.service_list.first.class                 # Playful::ControlPoint::Service
    p device.service_list.first.service_type          # "urn:schemas-upnp-org:service:ContentDirectory:1"

    # SOAP actions are converted to Ruby methods--show those
    p device.service_list.first.singleton_methods     # [:GetSystemUpdateID, :Search, :GetSearchCapabilities, :GetSortCapabilities, :Browse]

    # Call a SOAP method defined in the service.  The response is extracted from the
    # XML SOAP response and the value is converted from the UPnP dataType to
    # the related Ruby type.  Reponses are always contained in a Hash, so as
    # to maintain the relation defined in the service.
    p device.service_list.first.GetSystemUpdateID     # { :Id => 1 }
  end

  # Note that you don't have to check for items in the Channel or for when the
  # Channel is empty: EventMachine will pop objects off the Channel as soon as
  # they're put there and stop when there are none left.
  searcher.discovery_responses.pop do |notification|

    # Playful::ControlPoint::Device objects are EventMachine::Deferrables, so you
    # need to define callback and errback blocks to handle when the Device
    # object is done being created.
    device_creator = Playful::ControlPoint::Device.new(ssdp_notification: notification)

    device_creator.errback do
      puts "Failed creating the device."
      exit!
    end

    device_creator.callback do |built_device|
      puts "Device has been created now."

      # This lets the device_controller know that the device has been created,
      # calls its callback, and passes the built device to it.
      device_controller.set_deferred_status(:succeeded, built_device)
    end

    # This actually starts the Device creation process and will call the
    # callback or errback (above) when it's done.
    device_creator.fetch
  end
end

ControlPoints

If you're wanting to control devices and their services, you'll probably be more interested in using a Playful::ControlPoint, instead of doing all that work (above) to create a Playful::ControlPoint::Device. The ControlPoint will handle doing the search and device/service creation for you and will hand you over Devices to control them (and present them in a UI, perhaps?) as you need. More to come on this as the design settles down.

Requirements

  • Rubies (tested)
    • 1.9.3
    • 2.0.0
    • 2.1.0
  • Gems
    • eventmachine
    • em-http-request
    • em-synchrony
    • nori
    • log_switch
    • savon

Install

$ gem install playful --pre

Copyright

Copyright (c) 2012-2014 Steve Loveless

See LICENSE.md for details.