# Ruby Object Mapper

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[gem]: https://rubygems.org/gems/rom
[travis]: https://travis-ci.org/rom-rb/rom
[gemnasium]: https://gemnasium.com/rom-rb/rom
[codeclimate]: https://codeclimate.com/github/rom-rb/rom
[coveralls]: https://coveralls.io/r/rom-rb/rom
[inchpages]: http://inch-pages.github.io/github/rom-rb/rom/

Ruby Object Mapper is an implementation of [the Data Mapper](http://martinfowler.com/eaaCatalog/dataMapper.html)
pattern in Ruby language. It consists of multiple loosely coupled pieces and uses
a powerful relational algebra library called [axiom](https://github.com/dkubb/axiom).

## Getting started

Currently the setup is a bit verbose. Automatization will come in the future once
the API becomes stable.

```
gem install rom axiom-memory-adapter
```

### 1. Set up environment and define schema with mappings

```ruby
  require 'rom'
  require 'axiom-memory-adapter'

  class User
    attr_reader :id, :name

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

  env = ROM::Environment.setup(memory: 'memory://test') do
    schema do
      base_relation :users do
        repository :memory

        attribute :id,   Integer
        attribute :name, String

        key :id
      end
    end

    mapping do
      relation(:users) do
        map :id, :name
        model User
      end
    end
  end
```

### 2. Work with Plain Old Ruby Objects

```ruby
  env.session do |session|
    user = session[:users].new(id: 1, name: 'Jane')
    session[:users].save(user)
    session.flush
  end

  jane = env[:users].restrict(name: 'Jane').one
```

## Community

* #rom-rb channel on freenode
* [Ruby Object Mapper](https://groups.google.com/forum/#!forum/rom-rb) mailing list

## Authors

* [Dan Kubb](https://github.com/dkubb)
* [Markus Schirp](https://github.com/mbj)
* [Martin Gamsjaeger](https://github.com/snusnu)
* [Piotr Solnica](https://github.com/solnic)

## License

See `LICENSE` file.