Class: EventSorcerer::UnitOfWork

Inherits:
Object
  • Object
show all
Extended by:
Uber::Delegates
Defined in:
lib/event_sorcerer/unit_of_work.rb

Overview

Public: Provides transactional integrity across multiple aggregate saves.

Also provides an indentity map.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ UnitOfWork

Public: Creates a new UnitOfWork instance.



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# File 'lib/event_sorcerer/unit_of_work.rb', line 11

def initialize
  @identity_map  = {}
  @meta          = {}
  @pending_saves = []
end

Instance Method Details

#add_meta_data(meta_hash) ⇒ Object

Public: Add additional meta data to be sent along with any save reciepts

on the message bus for the duration of the unit of work.



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# File 'lib/event_sorcerer/unit_of_work.rb', line 19

def add_meta_data(meta_hash)
  meta.merge! meta_hash
end

#execute_work! ⇒ Object

Public: Executes all pending saves within a transaction, clears the

pending saves, and publishes the reciepts via the message bus.

Returns self.



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# File 'lib/event_sorcerer/unit_of_work.rb', line 27

def execute_work!
  save_receipts = event_store.with_transaction do
    pending_saves.map(&:call)
  end

  @pending_saves = []

  save_receipts.each do |reciept|
    message_bus.publish_events(reciept.id, reciept.klass, reciept.events,
                               reciept.meta.merge(meta))
  end

  self
end

#fetch_aggregate(id) ⇒ Object

Public: Fetches an aggregate via it’s ID from the identity map.

id - the ID for the aggregate.

Returns nil if not found. Returns Aggregate if found.



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# File 'lib/event_sorcerer/unit_of_work.rb', line 48

def fetch_aggregate(id)
  identity_map[id]
end

#handle_save(save) ⇒ Object 



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# File 'lib/event_sorcerer/unit_of_work.rb', line 52

def handle_save(save)
  pending_saves << save

  self
end

#store_aggregate(aggregate) ⇒ Object

Public: Stores an aggregate via it’s ID into the identity map.

aggregate - the aggregate to store.

Returns self.



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# File 'lib/event_sorcerer/unit_of_work.rb', line 63

def store_aggregate(aggregate)
  return self if fetch_aggregate(aggregate.id)

  identity_map[aggregate.id] = aggregate

  self
end