Class: ActionCable::Connection::Base

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, `::ActiveSupport::DescendantsTracker`
Instance Chain: self, `::ActiveSupport::Rescuable`, `Callbacks`, `::ActiveSupport::Callbacks`, `Authorization`, `InternalChannel`, `Identification`
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

`::ActiveSupport::Rescuable` - Attributes & Methods

.rescue_handlers rw
#rescue_handlers rw
.rescue_handlers? ⇒ Boolean rw
#rescue_handlers? ⇒ Boolean rw

Class Method Summary

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

`::ActiveSupport::DescendantsTracker` - self

descendants, subclasses

Instance Attribute Summary

#config readonly
#env readonly
#event_loop readonly
#logger readonly
#protocol readonly
#pubsub readonly
#server readonly
#subscriptions readonly
#worker_pool readonly

`Callbacks` - Included

#__callbacks

Instance Method Summary

#beat
#close(reason: nil, reconnect: true)

Close the WebSocket connection.
#handle_channel_command(payload)
#send_async(method, *arguments)

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

Return a basic hash of statistics for the connection keyed with identifier, started_at, #subscriptions, and request_id.
#cookies private

The cookies of the request that initiated the WebSocket connection.
#request private

The request that initiated the WebSocket connection is available here.

`::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 67


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 65


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

#env (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 64


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

#event_loop (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 65


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 64


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

#protocol (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 64


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

#pubsub (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 65


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 64


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

#subscriptions (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 64


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

#worker_pool (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 64


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

Instance Method Details

#beat

[ GitHub ]

# File 'actioncable/lib/action_cable/connection/base.rb', line 147


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 120


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 187


def cookies # :doc:
  request.cookie_jar
end

#handle_channel_command(payload)

[ GitHub ]

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


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 178


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 131


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 138


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

Class: ActionCable::Connection::Base

Overview

Constant Summary

::ActiveSupport::Callbacks - Included

Identification - Attributes & Methods

::ActiveSupport::Rescuable - Attributes & Methods

Class Method Summary

::ActiveSupport::DescendantsTracker - self

Instance Attribute Summary

Callbacks - Included

Instance Method Summary

::ActiveSupport::Rescuable - Included

::ActiveSupport::Callbacks - Included

Authorization - Included

Identification - Included

Constructor Details

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

Class Attribute Details

.identifiers (rw)

.identifiers? ⇒ Boolean (rw)

.rescue_handlers (rw)

.rescue_handlers? ⇒ Boolean (rw)

Instance Attribute Details

#config (readonly)

#env (readonly)

#event_loop (readonly)

#identifiers (rw)

#identifiers? ⇒ Boolean (rw)

#logger (readonly)

#protocol (readonly)

#pubsub (readonly)

#rescue_handlers (rw)

#rescue_handlers? ⇒ Boolean (rw)

#server (readonly)

#subscriptions (readonly)

#worker_pool (readonly)

Instance Method Details

#beat

#close(reason: nil, reconnect: true)

#cookies (private)

#handle_channel_command(payload)

#request (private)

#send_async(method, *arguments)

#statistics

`::ActiveSupport::Callbacks` - Included

`Identification` - Attributes & Methods

`::ActiveSupport::Rescuable` - Attributes & Methods

`::ActiveSupport::DescendantsTracker` - self

`Callbacks` - Included

`::ActiveSupport::Rescuable` - Included

`::ActiveSupport::Callbacks` - Included

`Authorization` - Included

`Identification` - Included

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

.identifiers? ⇒ `Boolean` (rw)

.rescue_handlers? ⇒ `Boolean` (rw)

#identifiers? ⇒ `Boolean` (rw)

#rescue_handlers? ⇒ `Boolean` (rw)