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Class: ActiveSupport::StructuredEventSubscriber

Do not use. This class is for internal use only.

Overview

===========================================

StructuredEventSubscriber consumes Notifications in order to emit structured events via Rails.event.

An example would be the Action Controller structured event subscriber, responsible for emitting request processing events:

module ActionController
  class StructuredEventSubscriber < ActiveSupport::StructuredEventSubscriber
    attach_to :action_controller

    def start_processing(event)
      emit_event("controller.request_started",
        controller: event.payload[:controller],
        action: event.payload[:action],
        format: event.payload[:format]
      )
    end
  end
end

After configured, whenever a "start_processing.action_controller" notification is published, it will properly dispatch the event (Notifications::Event) to the start_processing method. The subscriber can then emit a structured event via the #emit_event method.

Class Attribute Summary

Subscriber - Inherited

.namespace, .notifier, .subscriber

Class Method Summary

Subscriber - Inherited

.attach_to

Attach the subscriber to a namespace.
.detach_from

Detach the subscriber from a namespace.
.method_added

Adds event subscribers for all new methods added to the class.
.new, .subscribers, .add_event_subscriber, .fetch_public_methods, .find_attached_subscriber, .invalid_event?, .pattern_subscribed?, .prepare_pattern, .remove_event_subscriber

Instance Attribute Summary

Subscriber - Inherited

#patterns

Instance Method Summary

Subscriber - Inherited

#call

Constructor Details

.new ⇒ StructuredEventSubscriber

[ GitHub ] 

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 59



def initialize
  super
  @silenced_events = {}
end


  







Class Attribute Details



  

    .debug_methods   (rw)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 37



class_attribute :debug_methods, instance_accessor: false, default: [] # :nodoc:


  








  

    .debug_methods?  ⇒ Boolean  (rw)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 37



class_attribute :debug_methods, instance_accessor: false, default: [] # :nodoc:


  







Class Method Details



  

    .attach_to  
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 40



def attach_to(...) # :nodoc:
  result = super
  set_silenced_events
  result
end


  








  

    .debug_only(method)   (private)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 53



def debug_only(method)
  self.debug_methods += [method]
  set_silenced_events
end


  








  

    .set_silenced_events   (private)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 47



def set_silenced_events
  if subscriber
    subscriber.silenced_events = debug_methods.to_h { |method| ["#{method}.#{namespace}", true] }
  end
end


  







Instance Attribute Details



  

    #silenced_events=(value)   (writeonly)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 68



attr_writer :silenced_events # :nodoc:


  







Instance Method Details



  

    #call(event)  
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 91



def call(event)
  super
rescue => e
  handle_event_error(event.name, e)
end


  








  

    #emit_debug_event(name, payload = nil, caller_depth: 1, **kwargs)  
  



  

    
Like #emit_event, but only emits when the event reporter is in debug mode

  



  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 85



def emit_debug_event(name, payload = nil, caller_depth: 1, **kwargs)
  ActiveSupport.event_reporter.debug(name, payload, caller_depth: caller_depth + 1, filter_payload: false, **kwargs)
rescue => e
  handle_event_error(name, e)
end


  








  

    #emit_event(name, payload = nil, caller_depth: 1, **kwargs)  
  



  

    
Emit a structured event via Rails.event.notify.


Arguments


    

  • name - The event name as a string or symbol
    • 

  • payload - The event payload as a hash or object
    • 

  • caller_depth - Stack depth for source location (default: 1)
    • 

  • kwargs - Additional payload data merged with the payload hash
    • 


  



  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 78



def emit_event(name, payload = nil, caller_depth: 1, **kwargs)
  ActiveSupport.event_reporter.notify(name, payload, caller_depth: caller_depth + 1, filter_payload: false, **kwargs)
rescue => e
  handle_event_error(name, e)
end


  








  

    #handle_event_error(name, error)   (private)
  

  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 98



def handle_event_error(name, error)
  ActiveSupport.error_reporter.report(error, source: name)
end


  








  

    #silenced?(event)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activesupport/lib/active_support/structured_event_subscriber.rb', line 64



def silenced?(event)
  ActiveSupport.event_reporter.subscribers.none? || (@silenced_events.key?(event) && !ActiveSupport.event_reporter.debug_mode?)
end