Ruby Object Mapper

Gem Version Build Status Dependency Status Code Climate Test Coverage Inline docs

Ruby Object Mapper (ROM) is an experimental Ruby library with the goal to provide powerful object mapping capabilities without limiting the full power of your datastore.

Learn more:

Adapters

See issues for a list of adapters that are planned to be added soon.

ROM can be used with Rails next to ActiveRecord via rom-rails railtie. Integration with other frameworks is planned.

Synopsis

ROM.setup(:memory)

# This is our domain-specific class
class User
  attr_reader :name, :age

  def initialize(attributes)
    @name, @age = attributes.values_at(:name, :age)
  end
end

# Here we define user relation which encapsulates accessing user data that
# we can map to domain objects
class Users < ROM::Relation[:memory]
  def by_name(name)
    restrict(name: name)
  end

  def adults
    restrict { |user| user[:age] >= 18 }
  end
end

# Even though mappers can be derived from model definitions here's how you
# could define it explicitly
class UserMapper < ROM::Mapper
  relation :users
  register_as :entity

  model User

  attribute :name
  attribute :age
end

# You can define specialized commands that handle creating, updating and deleting
# data, those classes can use external input param handlers and validators too
class CreateUser < ROM::Commands::Create[:memory]
  register_as :create
  relation :users
  result :one
end

# finalize the setup and retrieve object registry (aka ROM env)
rom = ROM.finalize.env

# accessing defined commands
rom.command(:users).create.call(name: "Joe", age: 17)
rom.command(:users).create.call(name: "Jane", age: 18)

# reading relations using defined mappers
puts rom.relation(:users) { |r| r.by_name("Jane").adults }.as(:entity).to_a.inspect
# => [#<User:0x007fdba161cc48 @id=2, @name="Jane", @age=18>]

ROADMAP

ROM is on its way towards 1.0.0. Please refer to issues for details.

Community

Credits

This project has a long history and wouldn't exist without following people:

License

See LICENSE file.