Types

Custom types are the best way to share input-related logic between generators.

Built-in Ruby Types

Loci can automatically cast inputs to common Ruby types. These types require no extra setup and behave exactly as you expect.

arg :start_date, type: Date

params.start_date
# => #<Date ...>

params.start_date.class
# => Date

Custom Types

Any class that implements initialize(value) can be used as a type.

Here is a simplified custom type that represents a Rails resource.

# loci/types/rails/resource.rb

module Rails
  class Resource
    def initialize(raw)
      @raw = raw
    end

    def controller_path
      File.join("app", "controllers", "#{@raw.pluralize}_controller.rb")
    end

    def model_path
      File.join("app", "models", "#{@raw.singularize}.rb")
    end
  end
end

Using a Type in a Generator

arg :resource, type: Rails::Resource

Now the generator receives a rich object instead of a string.

params.resource.controller_path
# => "app/controllers/posts_controller.rb"

params.resource.model_path
# => "app/models/post.rb"