Module: Esse::Events::Publisher::ClassMethods

Defined in:
lib/esse/events/publisher.rb

Overview

Class interface for publishers

Instance Method Summary collapse

Instance Method Details

#__bus__ ⇒ Bus

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Internal event bus

Returns:



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# File 'lib/esse/events/publisher.rb', line 113

def __bus__
  @__bus__ ||= Bus.new
end

#instrument(event_id, payload = {}, &block) ⇒ Object

Publish an event with extra runtime information to the payload

Parameters:

  • event_id (String) —

    The event identifier

  • payload (Hash) (defaults to: {}) —

    An optional payload

Raises:



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# File 'lib/esse/events/publisher.rb', line 53

def instrument(event_id, payload = {}, &block)
  publish_event = false # ensure block is also called on error
  raise(UnregisteredEventError, event_id) unless __bus__.can_handle?(event_id)

  payload[:__started_at__] = Time.now
  block.call(payload).tap { publish_event = true }
ensure
  if publish_event
    payload[:runtime] ||= Time.now - payload.delete(:__started_at__) if payload[:__started_at__]
    __bus__.publish(event_id, payload)
  end
end

#publish(event_id, payload = {}) ⇒ Object

Publish an event

Parameters:

  • event_id (String) —

    The event identifier

  • payload (Hash) (defaults to: {}) —

    An optional payload

Raises:



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# File 'lib/esse/events/publisher.rb', line 37

def publish(event_id, payload = {})
  if __bus__.can_handle?(event_id)
    __bus__.publish(event_id, payload)
    self
  else
    raise UnregisteredEventError, event_id
  end
end

#register_event(event_id, payload = {}) ⇒ self

Register a new event type

Parameters:

  • event_id (Symbol, String) —

    The event identifier

  • payload (Hash) (defaults to: {}) —

    Optional default payload

Returns:

  • (self) 


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# File 'lib/esse/events/publisher.rb', line 25

def register_event(event_id, payload = {})
  __bus__.events[event_id] = Event.new(event_id, payload)
  self
end

#subscribe(object_or_event_id, &block) ⇒ Object

Subscribe to events.

Parameters:

  • object_or_event_id (Symbol, String, Object) —

    The event identifier or a listener object

  • filter_hash (Hash) —

    An optional event filter

Returns:

  • (Object) —

    self

Raises:



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# File 'lib/esse/events/publisher.rb', line 76

def subscribe(object_or_event_id, &block)
  if __bus__.can_handle?(object_or_event_id)
    if block
      __bus__.subscribe(object_or_event_id, &block)
    else
      __bus__.attach(object_or_event_id)
    end

    self
  else
    raise InvalidSubscriberError, object_or_event_id
  end
end

#subscribed?(listener) ⇒ Boolean

Return true if a given listener has been subscribed to any event

Returns:

  • (Boolean) 


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# File 'lib/esse/events/publisher.rb', line 104

def subscribed?(listener)
  __bus__.subscribed?(listener)
end

#unsubscribe(listener) ⇒ self

Unsubscribe a listener

Parameters:

  • listener (Object) —

    The listener object

Returns:

  • (self) 


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# File 'lib/esse/events/publisher.rb', line 97

def unsubscribe(listener)
  __bus__.detach(listener)
end