Class: Akasha::Aggregate

Inherits:

Object

• Object
• Akasha::Aggregate

Includes:

SyntaxHelpers

Defined in:

lib/akasha/aggregate.rb

Overview

CQRS Aggregate base class.

Usage:

class User < Akasha::Aggregate

def sign_up(email, password)
  changeset.append(:user_signed_up, email: email, password: password)
end

def on_user_signed_up(email:, password:, **_)
  @email = email
  @password = password
end

end

Instance Attribute Summary

• #changeset ⇒ Object readonly

  Returns the value of attribute changeset.

• #revision ⇒ Object readonly

  Returns the value of attribute revision.

Instance Method Summary

• #apply_events(events) ⇒ Object

  Replay events, building up the state of the aggregate.

• #initialize(id) ⇒ Aggregate constructor

  A new instance of Aggregate.

Methods included from SyntaxHelpers

included

Constructor Details

#initialize(id) ⇒ Aggregate

Returns a new instance of Aggregate.

# File 'lib/akasha/aggregate.rb', line 24

def initialize(id)
  @revision = -1 # No stream exists.
  @changeset = Changeset.new(id)
end

Instance Attribute Details

#changeset ⇒ Object (readonly)

Returns the value of attribute changeset.

# File 'lib/akasha/aggregate.rb', line 22

def changeset
  @changeset
end

#revision ⇒ Object (readonly)

Returns the value of attribute revision.

# File 'lib/akasha/aggregate.rb', line 22

def revision
  @revision
end

Instance Method Details

#apply_events(events) ⇒ Object

Replay events, building up the state of the aggregate. Used by Repository.

# File 'lib/akasha/aggregate.rb', line 31

def apply_events(events)
  events.each do |event|
    method_name = event_handler(event)
    public_send(method_name, event.data) if respond_to?(method_name)
  end
  @revision = events.last&.revision.to_i
end