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