(That's) Not My Job
Also known as Empleado Público ;) provides a delegate class method to easily expose contained object's methods as your own.
Quick install
Add this line to your application's Gemfile:
gem 'not_my_job'
And then execute:
$ bundle install
Or install it yourself as:
$ gem install not_my_job
Usage
delegate(*methods, to: target [, with_prefix: true|false ]) { block } → obj
In order to access the delegate object's methods, NotMyJob creates instance methods for each one specified method.
If the delegate object is nil, there are several options: If no block is provided, it will raise a NoMethodError exception; if the optional code block is specified you may return an alternate value, or to take some arbitrary action.
Examples
Simple delegation:
class Cuisine
attr_accessor :name, :chef
def initialize(name, chef)
@name = name
@chef = chef
end
end
class Restaurant
extend NotMyJob
delegate :name, to: :cuisine
delegate :chef, to: :cuisine, with_prefix: false
def initialize(cuisine)
@cuisine = cuisine
end
end
cuisine = Cuisine.new("Italian", "Mario")
restaurant = Restauran.new(cuisine)
restaurant.cuisine_name #=> "Italian"
restaurant.chef #=> "Mario"Multiple methods delegation:
class Restaurant
extend NotMyJob
delegate :name, :chef to: :cuisine
end
restaurant.cuisine_name #=> "Italian"
restaurant.cuisine_chef #=> "Mario"With ActiveRecord associations:
class Restaurant < ActiveRecord::Base
extend NotMyJob
belongs_to :place
delegate :name, to: :place
end
restaurant.place_name #=> "Argentina"If the delegate object is nil and a block is specified:
class Restaurant
extend NotMyJob
delegate :name, to: :category do
logger.debug "Category is nil"
send_notification_email
"No category has been assigned to this restaurant"
end
end
restaurant.category_name #=> "No category has been assigned to this restaurant"