dry-initializer-rails

Installation

Add this line to your application's Gemfile:

gem 'dry-initializer-rails'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dry-initializer-rails

Synopsis

The gem provides value coercion to ActiveRecord instances.

Add the :model setting to param or option:

require 'dry-initializer'
require 'dry-initializer-rails'

class CreateOrder
  extend Dry::Initializer

  # Params and options
  param  :customer, model: 'Customer'                 # use either a name
  option :product,  model: Product                    # or a class
  option :coupon,   model: Coupon.where(active: true) # or relation

  def call
    Order.create customer: customer, product: product, coupon: coupon
  end
end

Now you can assign values as pre-initialized model instances:

customer = Customer.create(id: 1)
product  = Product.create(id: 2)
coupon   = Coupon.create(id: 3, active: true)

order = CreateOrder.new(customer, product: product, coupon: coupon).call
order.customer # => #<Customer @id=1 ...>
order.product  # => #<Product @id=2 ...>
order.coupon   # => #<Coupon @id=3 ...>

...or their ids:

order = CreateOrder.new(1, product: 2, coupon: 3).call
order.customer # => #<Customer @id=1 ...>
order.product  # => #<Product @id=2 ...>
order.coupon   # => #<Coupon @id=3 ...>

The instance is envoked using method find_by!(id: ...).

order = CreateOrder.new(1, product: 2, coupon: 4).call
# raises #<ActiveRecord::RecordNotFound>

You can specify custom key for searching model instance:

require 'dry-initializer-rails'

class CreateOrder
  extend Dry::Initializer

  param  :customer, model: 'User', find_by: 'name'
  option :product,  model: Item,   find_by: :name
end

This time you can pass names (not ids) to the initializer:

order = CreateOrder.new('Andrew', product: 'the_thing_no_123').call

order.customer # => <User @name='Andrew' ...>
order.product  # => <Item @name='the_thing_no_123' ...>

Compatibility

Tested under MRI 2.2+.

Contributing

Fork the project
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.