Class: ActionCable::Connection::Base

Inherits:
Object
  • Object
show all
Includes:
Authorization, Callbacks, Identification, InternalChannel, ActiveSupport::Rescuable
Defined in:
lib/action_cable/connection/base.rb

Overview

# Action Cable Connection Base

For every WebSocket connection the Action Cable server accepts, a 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.

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Authorization

#reject_unauthorized_connection

Methods included from Identification

#connection_identifier

Constructor Details

#initialize(server, socket) ⇒ Base

Returns a new instance of Base.



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# File 'lib/action_cable/connection/base.rb', line 68

def initialize(server, socket)
  @server = server
  @socket = socket

  @logger = socket.logger
  @subscriptions  = Subscriptions.new(self)

  @_internal_subscriptions = nil

  @started_at = Time.now
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/action_cable/connection/base.rb', line 62

def logger
  @logger
end

#server ⇒ Object (readonly)

Returns the value of attribute server.



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# File 'lib/action_cable/connection/base.rb', line 63

def server
  @server
end

#socket ⇒ Object (readonly)

Returns the value of attribute socket.



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# File 'lib/action_cable/connection/base.rb', line 63

def socket
  @socket
end

#subscriptions ⇒ Object (readonly)

Returns the value of attribute subscriptions.



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# File 'lib/action_cable/connection/base.rb', line 62

def subscriptions
  @subscriptions
end

Instance Method Details

#beat ⇒ Object 



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# File 'lib/action_cable/connection/base.rb', line 142

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

#close(reason: nil, reconnect: true) ⇒ Object

Close the connection.



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# File 'lib/action_cable/connection/base.rb', line 121

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

#connect ⇒ Object

This method is called every time an Action Cable client establishes an underlying connection. Override it in your class to define authentication logic and populate connection identifiers.



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# File 'lib/action_cable/connection/base.rb', line 83

def connect
end

#disconnect ⇒ Object

This method is called every time an Action Cable client disconnects. Override it in your class to cleanup the relevant application state (e.g., presence, online counts, etc.)



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# File 'lib/action_cable/connection/base.rb', line 88

def disconnect
end

#handle_channel_command(payload) ⇒ Object Also known as: handle_incoming 



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# File 'lib/action_cable/connection/base.rb', line 106

def handle_channel_command(payload)
  run_callbacks :command do
    subscriptions.execute_command payload
  end
rescue Exception => e
  rescue_with_handler(e) || raise
end

#handle_close ⇒ Object 



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# File 'lib/action_cable/connection/base.rb', line 99

def handle_close
  subscriptions.unsubscribe_from_all
  unsubscribe_from_internal_channel

  disconnect
end

#handle_open ⇒ Object 



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# File 'lib/action_cable/connection/base.rb', line 91

def handle_open
  connect
  subscribe_to_internal_channel
  send_welcome_message
rescue ActionCable::Connection::Authorization::UnauthorizedError
  close(reason: ActionCable::INTERNAL[:disconnect_reasons][:unauthorized], reconnect: false)
end

#inspect ⇒ Object

:nodoc:



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# File 'lib/action_cable/connection/base.rb', line 146

def inspect # :nodoc:
  "#<#{self.class.name}:#{'%#016x' % (object_id << 1)}>"
end

#statistics ⇒ Object

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.



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# File 'lib/action_cable/connection/base.rb', line 133

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

#transmit(data) ⇒ Object

:nodoc:



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# File 'lib/action_cable/connection/base.rb', line 116

def transmit(data) # :nodoc:
  socket.transmit(data)
end