# dry-initializer [![Join the chat at https://gitter.im/dry-rb/chat](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/dry-rb/chat)

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[![Build Status](https://travis-ci.org/dry-rb/dry-initializer.svg?branch=master)][travis]
[![Dependency Status](https://gemnasium.com/dry-rb/dry-initializer.svg)][gemnasium]
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[![Inline docs](http://inch-ci.org/github/dry-rb/dry-initializer.svg?branch=master)][inchpages]

[gem]: https://rubygems.org/gems/dry-initializer
[travis]: https://travis-ci.org/dry-rb/dry-initializer
[gemnasium]: https://gemnasium.com/dry-rb/dry-initializer
[codeclimate]: https://codeclimate.com/github/dry-rb/dry-initializer
[coveralls]: https://coveralls.io/r/dry-rb/dry-initializer
[inchpages]: http://inch-ci.org/github/dry-rb/dry-initializer
[docs]: http://dry-rb.org/gems/dry-initializer/
[benchmarks]: https://github.com/dry-rb/dry-initializer/wiki
[license]: http://opensource.org/licenses/MIT

DSL for building class initializer with params and options.

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'dry-initializer'
```

And then execute:

```shell
$ bundle
```

Or install it yourself as:

```shell
$ gem install dry-initializer
```

## Synopsis

```ruby
require 'dry-initializer'
require 'dry-types'

class User
  extend Dry::Initializer

  # Params of the initializer along with corresponding readers
  param  :name,  proc(&:to_s)
  param  :role,  default: -> { 'customer' }
  # Options of the initializer along with corresponding readers
  option :admin, default: -> { false }
  option :vip,   optional: true
end

# Defines the initializer with params and options
user = User.new 'Vladimir', 'admin', admin: true

# Defines readers for single attributes
user.name  # => 'Vladimir'
user.role  # => 'admin'
user.admin # => true
user.vip   # => Dry::Initializer::UNDEFINED
```

See full documentation on the [Dry project official site][docs]

## Benchmarks

The `dry-initializer` is pretty fast for rubies 2.2+ [comparing to other libraries][benchmarks].

## Compatibility

Tested under rubies [compatible to MRI 2.2+](.travis.yml).

## Contributing

* [Fork the project](https://github.com/dry-rb/dry-initializer)
* Create your feature branch (`git checkout -b my-new-feature`)
* Add tests for it
* Commit your changes (`git commit -am '[UPDATE] Add some feature'`)
* Push to the branch (`git push origin my-new-feature`)
* Create a new Pull Request

## License

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