Module: EMRPC::Subscribable

Defined in:
lib/emrpc/evented_api/subscribable.rb

Overview

Enables subscribing and unsubscribing using

  • #subscribe(:event_name, rcvr, :callback)

  • #unsubscribe(:event_name, rcvr[, :callback]) (if no callback is defined, all callbacks for the current pid are removed)

  • #notify_subscribers(:event_name)

Instance Method Summary collapse

Instance Method Details

#initialize(*args, &blk) ⇒ Object 



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# File 'lib/emrpc/evented_api/subscribable.rb', line 8

def initialize(*args, &blk)
  super(*args, &blk)
  @subscriptions = Hash.new # event_name -> array of [pid, callback]
end

#notify_subscribers(event_name, *args, &blk) ⇒ Object

Sends callback messages to all subscribed pids. If event is not registered, returns 0. Otherwise returns number of notifications.



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# File 'lib/emrpc/evented_api/subscribable.rb', line 47

def notify_subscribers(event_name, *args, &blk)
  subscriptions = @subscriptions[event_name] or return 0
  subscriptions.each do |(pid, cbk)|
    pid.send(cbk, *args, &blk)
  end
  subscriptions.size
end

#subscribe(event_name, pid, callback_name) ⇒ Object

Subscribes pid to event event_name with callback callback_name



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# File 'lib/emrpc/evented_api/subscribable.rb', line 15

def subscribe(event_name, pid, callback_name)
  @subscriptions[event_name] ||= Array.new
  @subscriptions[event_name] << [pid, callback_name]
  self
end

#unsubscribe(event_name = nil, pid = nil, callback_name = nil) ⇒ Object

Depending on the arguments passed:

  • unsubscribe(:event, pid, :on_event) -> unsubscribes the callback for the specified pid and event

  • unsubscribe(:event, pid) -> unsubscribes all callbacks for the pid and the event

  • unsubscribe(:event) -> unsubscribes all pids and callbacks for the event

  • unsubscribe -> unsubscribes all pids and callbacks for all events

  • unsubscribe(:all, pid) -> unsubscribes pid from all events

  • unsubscribe(:all, pid, :on_event) -> unsubscribes pid’s :on_event callback from all events



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# File 'lib/emrpc/evented_api/subscribable.rb', line 29

def unsubscribe(event_name = nil, pid = nil, callback_name = nil)
  if !event_name || event_name == :all
    @subscriptions.each do |event, subscriptions|
      unsubscribe(event, pid, callback_name)
    end
  else
    subscriptions = @subscriptions[event_name] or return self
    subscriptions.delete_if do |pair|
      pd, cb = pair
      (pd == pid || !pid) && (cb == callback_name || !callback_name)
    end
  end
  self
end