NullObjectLoader

This little gem lets you declare what null objects to instantiate if a certain method call returns nil.

Installation

Add this line to your application's Gemfile:

gem 'null_object_loader'

And then execute:

$ bundle

Or install it yourself as:

$ gem install null_object_loader

Usage

In your class

include NullObjectLoader

Then, if you would like to load a null object if a method returns nil:

load_null_object :method_name_here, :null_class => NullObjectClassHere

Example:

class OldSchool
  attr_accessor :principal
  def initialize(principal = nil)
    @principal = principal
  end
end
OldSchool.new.principal.name # => NameError: Undefined method 'name' for nil:NilClass

Now, with NullObjectLoader

class NullPrincipal
  def name; "No Principal"; end
end

class NewSchool < OldSchool
  include NullObjectLoader

  load_null_object :principal, :null_class => NullPrincipal
end
NewSchool.new.principal.name # => "No Principal"

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request