Brief intro to ROM project.

1. ROM

2. PERSISTENCE & MAPPING
TOOLKIT FOR RUBY

3. NO COMPLEX
& LEAKY ABSTRACTIONS

4. REDUCES GLOBAL
STATE TO THE MINIMUM

5. FIGHTS WITH
MUTABLE STATE

6. PROMOTES OBJECT
COMPOSITION

7. MIXES FP WITH OO

8. CORE CONCEPTS
▸ Configuration
▸ Relations
▸ Pipelines
▸ Commands

9. CONFIGURATION

10. require 'rom'
config = ROM::Configuration.new(
:sql, 'postgres://localhost/rom_repository'
)
rom = ROM.container(config)
rom.gateways[:default]
# #<ROM::SQL::Gateway:0x007fde7a087158>

11. RELATIONS

12. class Users < ROM::Relation[:sql]
def sorted
order(:name)
end
end
JUST DATA
QUERY LOGIC
rom.relations[:users].sorted
# [{:id=>1, :name=>"Jane"}

13. RELATIONS ARE CALLABLE

14. rom.relations[:users].call
# [{:id=>1, :name=>"Jane"}]
rom.relations[:users].where(name: 'Jane').call
# [{:id=>1, :name=>"Jane"}]
rom.relations[:users].where(name: 'Joe').call
# []

15. PIPELINE

16. map_names = -> users { users.map { |user| user[:name] } }
user_names = rom.relations[:users] >> map_names
user_names.call
# ["Jane"]
PIPELINE OPERATOR

17. COMMANDS

18. class CreateUser < ROM::Commands::Create[:sql]
relation :users
register_as :create
result :one
end
create_user = rom.commands[:users][:create]
create_user.call(name: 'Joe')
# [{:id=>2, :name=>"Joe"}

19. DOMAIN DATA TYPES &
REPOSITORIES

20. class User < Dry::Data::Value
attribute :name, Types::Strict::String
end
class UserRepo < ROM::Repository
relations :users
def all
users.select(:name).as(User).to_a
end
end

21. user_repo = UserRepo.new(rom)
user_repo.all
# [#<User name="Jane">, #<User name="Joe">]

22. PROJECT STATUS

23. STATUS
▸ rom core 1.0.0 released last Wednesday
▸ further work needed to make adapters and extensions
stable too
▸ desperately needs a new set of user guides and tutorials
▸ already runs on production

24. @rom_rb
rom-rb.org
Ruby Object Mapper

25. @dry_rb
github.com/dryrb
dryrb

26. @_solnic_
solnic.eu
Piotr Solnica

27. THANK YOU :)