Naughty or Nice
Naughty or Nice simplifies the process of extracting domain information from a domain-like string (an email, a URL, etc.) and checking whether it meets criteria you specify.
Usage
Naughty or Nice doesn’t do too much on its own. Out of the box, it can extract a domain from a domain-like string, and can verify that it is, in fact, a valid domain. It does this by leveraging the power of Addressable, the Public Suffix List, and the associated Ruby Gem.
The true power of Naughty or Nice comes when you include it into your own class.
Implementing Naughty or Nice
Let’s say you have a list of three domains, foo.com, bar.com, and foobar.com. You’d spec out a class like so:
```ruby class Checker
include NaughtyOrNice DOMAINS = %w[foo.com bar.com foobar.com]
def valid? DOMAINS.include? domain.to_s end end ```
That’s it! Just overwrite the valid? method and Naughty or Nice takes care of the rest.
You can also get more complicated. Let’s say you only wanted to allow .gov domains:
```ruby class Checker
include NaughtyOrNice
def valid? domain.tld == “gov” end end ```
Using the included methods
There are a handful of magic methods that your class automatically gets. You can throw any domain-like string at your new Checker class, and figure out if it’s on the list. Here’s a few examples:
ruby
Checker.valid? "foo.com" #=> true
Checker.valid? "foo.org" #=> false
Notice we’re using the class method valid? That automatically calls Checker.new(string).valid? for you. Cool, huh?
But you don’t just need to give Checker crisp, clean domains. Let’s get a bit trickier:
ruby
Checker.valid? "http://foo.bar.com" #=> true
Checker.valid? "[email protected]" #=> true
Checker.valid? "foobar" => false
Extracting domain information
You can also you NaughtyOrNice to extract domain information for use elsewhere. Continuing our above example:
ruby
address = Checker.new "[email protected]"
address.valid? #=> true
address.domain.to_s #=> "foo.bar.com"
address.domain.tld #=> "com"
address.domain.sld #=> "bar"
See it in action
Take a look at Gman to see Naughty or Nice in action. Gman uses a crowd-sourced list of government domains to check if a given email address is a government email.