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|
module ActionCable
module Channel
class Base
include Callbacks
include Redis
on_subscribe :start_periodic_timers
on_unsubscribe :stop_periodic_timers
attr_reader :params, :connection
delegate :logger, to: :connection
class << self
def matches?(identifier)
raise "Please implement #{name}#matches? method"
end
end
def initialize(connection, channel_identifier, params = {})
@connection = connection
@channel_identifier = channel_identifier
@_active_periodic_timers = []
@params = params
perform_connection
end
def perform_connection
logger.info "#{channel_name} connecting"
connect
run_subscribe_callbacks
end
def perform_action(data)
if authorized?
action = extract_action(data)
if performable_action?(action)
logger.info channel_name + compose_signature(action, data)
public_send action, data
else
logger.error "#{channel_name} failed to process #{compose_signature(action, data)}"
end
else
unauthorized
end
end
def perform_disconnection
disconnect
run_unsubscribe_callbacks
logger.info "#{channel_name} disconnected"
end
protected
# Override in subclasses
def authorized?
true
end
def unauthorized
logger.error "#{channel_name}: Unauthorized access"
end
def connect
# Override in subclasses
end
def disconnect
# Override in subclasses
end
def transmit(data, via: nil)
if authorized?
logger.info "#{channel_name} transmitting #{data.inspect}".tap { |m| m << " (via #{via})" if via }
connection.transmit({ identifier: @channel_identifier, message: data }.to_json)
else
unauthorized
end
end
def channel_name
self.class.name
end
private
def extract_action(data)
(data['action'].presence || :receive).to_sym
end
def performable_action?(action)
self.class.instance_methods(false).include?(action)
end
def compose_signature(action, data)
"##{action}".tap do |signature|
if (arguments = data.except('action')).any?
signature << "(#{arguments.inspect})"
end
end
end
def run_subscribe_callbacks
self.class.on_subscribe_callbacks.each { |callback| send(callback) }
end
def run_unsubscribe_callbacks
self.class.on_unsubscribe_callbacks.each { |callback| send(callback) }
end
def start_periodic_timers
self.class.periodic_timers.each do |callback, options|
@_active_periodic_timers << EventMachine::PeriodicTimer.new(options[:every]) do
worker_pool.async.run_periodic_timer(self, callback)
end
end
end
def stop_periodic_timers
@_active_periodic_timers.each { |timer| timer.cancel }
end
def worker_pool
connection.worker_pool
end
end
end
end
|
