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Class: ActionCable::Connection::Base

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
Inherits: Object
Defined in: actioncable/lib/action_cable/connection/base.rb

Overview

For every WebSocket connection the Action Cable server accepts, a ::ActionCable::Connection object will be instantiated. This instance becomes the parent of all of the channel subscriptions that are created from there on. Incoming messages are then routed to these channel subscriptions based on an identifier sent by the Action Cable consumer. The Connection itself does not deal with any specific application logic beyond authentication and authorization.

Here’s a basic example:

module ApplicationCable
  class Connection < ActionCable::Connection::Base
    identified_by :current_user

    def connect
      self.current_user = find_verified_user
      logger.add_tags current_user.name
    end

    def disconnect
      # Any cleanup work needed when the cable connection is cut.
    end

    private
      def find_verified_user
        User.find_by_identity(cookies.encrypted[:identity_id]) ||
          reject_unauthorized_connection
      end
  end
end

First, we declare that this connection can be identified by its current_user. This allows us to later be able to find all connections established for that current_user (and potentially disconnect them). You can declare as many identification indexes as you like. Declaring an identification means that an attr_accessor is automatically set for that key.

Second, we rely on the fact that the WebSocket connection is established with the cookies from the domain being sent along. This makes it easy to use signed cookies that were set when logging in via a web interface to authorize the WebSocket connection.

Finally, we add a tag to the connection-specific logger with the name of the current user to easily distinguish their messages in the log.

Pretty simple, eh?

Constant Summary

::ActiveSupport::Callbacks - Included

CALLBACK_FILTER_TYPES

Identification - Attributes & Methods

::ActiveSupport::Rescuable - Attributes & Methods

Class Method Summary

::ActiveSupport::DescendantsTracker - self

descendants

See additional method definition at line 104.

subclasses

See additional method definition at line 100.

Instance Attribute Summary

Callbacks - Included

Instance Method Summary

::ActiveSupport::Rescuable - Included

#rescue_with_handler

Delegates to the class method, but uses the instance as the subject for rescue_from handlers (method calls, instance_exec blocks).

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.

Authorization - Included

#reject_unauthorized_connection

Closes the WebSocket connection if it is open and returns an “unauthorized” reason.

Identification - Included

#connection_identifier

Return a single connection identifier that combines the value of all the registered identifiers into a single gid.

Constructor Details

.new(server, env, coder: ActiveSupport::JSON) ⇒ Base

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 58

def initialize(server, env, coder: ActiveSupport::JSON)
  @server, @env, @coder = server, env, coder

  @worker_pool = server.worker_pool
  @logger = new_tagged_logger

  @websocket      = ActionCable::Connection::WebSocket.new(env, self, event_loop)
  @subscriptions  = ActionCable::Connection::Subscriptions.new(self)
  @message_buffer = ActionCable::Connection::MessageBuffer.new(self)

  @_internal_subscriptions = nil
  @started_at = Time.now
end

Class Attribute Details

.identifiers (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/identification.rb', line 11

class_attribute :identifiers, default: Set.new

.identifiers?Boolean (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/identification.rb', line 11

class_attribute :identifiers, default: Set.new

.rescue_handlers (rw)

[ GitHub ]

  
# File 'activesupport/lib/active_support/rescuable.rb', line 15

class_attribute :rescue_handlers, default: []

.rescue_handlers?Boolean (rw)

[ GitHub ]

  
# File 'activesupport/lib/active_support/rescuable.rb', line 15

class_attribute :rescue_handlers, default: []

Instance Attribute Details

#config (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 56

delegate :event_loop, :pubsub, :config, to: :server

#env (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

#event_loop (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 56

delegate :event_loop, :pubsub, :config, to: :server

#identifiers (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/identification.rb', line 11

class_attribute :identifiers, default: Set.new

#identifiers?Boolean (rw)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/identification.rb', line 11

class_attribute :identifiers, default: Set.new

#logger (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

#protocol (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

#pubsub (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 56

delegate :event_loop, :pubsub, :config, to: :server

#rescue_handlers (rw)

[ GitHub ]

  
# File 'activesupport/lib/active_support/rescuable.rb', line 15

class_attribute :rescue_handlers, default: []

#rescue_handlers?Boolean (rw)

[ GitHub ]

  
# File 'activesupport/lib/active_support/rescuable.rb', line 15

class_attribute :rescue_handlers, default: []

#server (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

#subscriptions (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

#worker_pool (readonly)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 55

attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol

Instance Method Details

#beat

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 134

def beat
  transmit type: ActionCable::INTERNAL[:message_types][:ping], message: Time.now.to_i
end

#close(reason: nil, reconnect: true)

Close the WebSocket connection.

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 109

def close(reason: nil, reconnect: true)
  transmit(
    type: ActionCable::INTERNAL[:message_types][:disconnect],
    reason: reason,
    reconnect: reconnect
  )
  websocket.close
end

#cookies (private)

The cookies of the request that initiated the WebSocket connection. Useful for performing authorization checks.

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 172

def cookies # :doc:
  request.cookie_jar
end

#handle_channel_command(payload)

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 98

def handle_channel_command(payload)
  run_callbacks :command do
    subscriptions.execute_command payload
  end
end

#request (private)

The request that initiated the WebSocket connection is available here. This gives access to the environment, cookies, etc.

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 164

def request # :doc:
  @request ||= begin
    environment = Rails.application.env_config.merge(env) if defined?(Rails.application) && Rails.application
    ActionDispatch::Request.new(environment || env)
  end
end

#send_async(method, *arguments)

Invoke a method on the connection asynchronously through the pool of thread workers.

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 119

def send_async(method, *arguments)
  worker_pool.async_invoke(self, method, *arguments)
end

#statistics

Return a basic hash of statistics for the connection keyed with identifier, started_at, #subscriptions, and request_id. This can be returned by a health check against the connection.

[ GitHub ]

  
# File 'actioncable/lib/action_cable/connection/base.rb', line 125

def statistics
  {
    identifier: connection_identifier,
    started_at: @started_at,
    subscriptions: subscriptions.identifiers,
    request_id: @env["action_dispatch.request_id"]
  }
end