Module: Eventsimple::Event::ClassMethods

Defined in:
lib/eventsimple/event.rb

Instance Method Summary collapse

Instance Method Details

#create(*args, &block) ⇒ Object

We want to automatically retry writes on concurrency failures. However events with sync reactors may have multiple nested events that are written within the same transaction. We can only catch and retry writes when we are in the outermost transaction.



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# File 'lib/eventsimple/event.rb', line 203

def create(*args, &block)
  with_locks do
    with_retries(args) { super }
  end
end

#create!(*args, &block) ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 209

def create!(*args, &block)
  with_locks do
    with_retries(args) { super }
  end
end

#existing_transaction_in_progress? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/eventsimple/event.rb', line 238

def existing_transaction_in_progress?
  ActiveRecord::Base.connection.transaction_open?
end

#find_sti_class(type_name) ⇒ Object

We don’t store the full namespaced class name in the events table. Events for an entity are expected to be namespaced under _events_namespace.



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# File 'lib/eventsimple/event.rb', line 176

def find_sti_class(type_name)
  if _events_namespace.blank?
    super
  else
    super("#{_events_namespace}::#{type_name}")
  end
end

#inherited(subclass) ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 157

def inherited(subclass)
  super
  subclass.attribute :data, Eventsimple::DataType.new(subclass)
end

#rescue_invalid_transition(&block) ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 166

def rescue_invalid_transition(&block)
  self._on_invalid_transition = block || ->(error) {}
end

#resolve_metadata_klass ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 170

def resolve_metadata_klass
  _metadata_klass || Eventsimple::Metadata
end

#sti_class_for(type_name) ⇒ Object

Use a no-op deleted class for events that no longer exist in the codebase



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# File 'lib/eventsimple/event.rb', line 185

def sti_class_for(type_name)
  super
rescue ActiveRecord::SubclassNotFound
  klass_name = "Deleted__#{type_name.demodulize}"
  return const_get(klass_name) if const_defined?(klass_name)

  klass = Class.new(self) do
    def deleted?
      true
    end
  end

  const_set(klass_name, klass)
end

#validate_with(form_klass) ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 162

def validate_with(form_klass)
  @validate_with = form_klass
end

#with_locks ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 215

def with_locks(&)
  if _outbox_enabled
    base_class.with_advisory_lock(base_class.name, { transaction: existing_transaction_in_progress? }, &)
  else
    yield
  end
end

#with_retries(args) ⇒ Object 



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# File 'lib/eventsimple/event.rb', line 223

def with_retries(args, &)
  entity = args[0][_aggregate_klass.model_name.element.to_sym]

  # Only implement retries when the event is not already inside a transaction.
  if entity&.persisted? && !existing_transaction_in_progress?
    Retriable.with_context(:optimistic_locking, on_retry: proc { entity.reload }, &)
  else
    yield
  end
rescue ActiveRecord::StaleObjectError => e
  raise e unless existing_transaction_in_progress?

  raise e, "#{e.message} No retries are attempted when already inside a transaction."
end