Event ID Mapper

Event ID Mapper is a plug-in for Rails Event Store (RES) library that let you serialize and control the event_id format perceived by the repository.
Its original purpose is to encode the primary key and the foreign key in binary format for MySQL compatible databases. Leveraging on ActiveRecord repository for the underlying repository implementation.
However, since the mapper is generic you can easily use it with any Ruby Event Store repository implementations.

*** Obsoleted ***

The upstream introduced too many breaking changes. (e.g., unconfigurable schema checking)
I can't keep following to make this gem useful, and also I have a lot of disagreements on how the event repository should be done.
I moved on, but feel free to fork.

Installation

Add ruby_event_store_event_id_mapper to the Gemfile:

gem 'ruby_event_store_event_id_mapper'

Download and install by running:

bundle install

Basic usage

for ActiveRecord repository and MySQL

When Rails Event Store generates a migration for you. You can edit the migration file to suit your needs.
For instance:

def change
  create_table(:event_store_events, id: :binary, limit: 16, force: false) do |t|
    t.string   :event_type,                                    null: false
    t.binary   :data,       limit: 256.kilobytes,              null: false
    t.binary   :metadata,   limit: 256.kilobytes
    t.datetime :created_at,                       index: true, null: false
  end

  create_table(:event_store_events_in_streams, force: false) do |t|
    t.string   :stream,                                        null: false
    t.integer  :position
    t.binary   :event_id,   limit: 16,            index: true, null: false
    t.datetime :created_at,                       index: true, null: false
  end
  add_index :event_store_events_in_streams, [:stream, :position], unique: true
  add_index :event_store_events_in_streams, [:stream, :event_id], unique: true
end

Please note the limit: 16 addition on the primary and foreign key attributes.
Now in Ruby code, you can create an event_store instance with a custom repository following the guide on Rails Event Store website letting RubyEventStoreEventIdMapper::RepositoryWrapper tap in.

event_store = RailsEventStore::Client.new(
  repository: RubyEventStoreEventIdMapper::RepositoryWrapper.new(
    repository: RailsEventStoreActiveRecord::EventRepository.new,
    serializer: RubyEventStoreEventIdMapper::BinaryUUIDSerializer,
  )
)

It is recommended to verify the compatibility of your setup with the test suite provided by Ruby Event Store.
It is also recommended to see how this tiny gem actually works.

for other uses

It is possible that you have a better use case for the mapper but for now, I can't think of any concrete one.

Code status

Contributing

Bug reports, pull requests, and inquiries are welcome on the GitHub repository.

License

The gem is available as open source under the terms of the MIT License.