#Dnsaur
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Dnsaur is a simple DNS checker / email corrector for ruby. This gem does three things; when a user misspells a domain, it suggests the right spelling, it provide simple reverse DNS helper methods to help verifiy these emails, and splits emails into three parts(top level domain, domain, address).

The email suggestion part of the gem is based off a small javascript library called
[mailcheck.js](https://github.com/mailcheck/mailcheck). If you are looking for a more front end
solution for correcting email input, I suggest checking this out.

## How the suggest works

When your user types in "user@hotnail.con", Dnsaur will suggest "user@hotmail.com". It can also
suggest top level domains, where a user types "user@hotmail.cmo" and would suggest ".com"

It does this by comparing a list of popular default domains and defualt top level domains suplied to
the gem.

## Usage
Dnsaur can be used ether as an instance or as class methods. When creating an instance you need to
supply it with email,
```ruby
email = "test@example.com"
dns = Dnsaur.new email
=> #<Dnsaur:0x007fb8ea17d590 @original_email="test@example.com", ...
```
custom domains and/or custom top level domains are optional.
For more information on custom domain, see the `Domains`section below.

### Email Suggestion/Correction

In the suggest method, you can pass an email and it will return a suggested email in a hash
example:
```ruby
# Class Methods
email = "test@hotnail.con"
Dnsaur.suggest email
=>
{
  address:          'test',             // the address; part before the @ sign
  domain:           'hotmail.com',      // the suggested domain
  top_level_domain: 'com',              // the suggested top level domain
  full:             'test@hotmail.com'  // the full suggested email
}
```
If there is no match, or it is an exact match to a defualt domain, it will return false.

### Reverse DNS lookup Helpers
The DNS lookup for this gem uses `Resolv` from the ruby stdlib, but I supplied class/instanced helper methods
for ease of use. If you have an instances of the class, it

```ruby
#Class Methods
email = "test@example.com"
Dnsaur.valid_dns? email
=> true || false

#Instant Methods
email = "test@hotnail.com"
dns = Dnsaur.new email
dns.valid_original_dns?
=> true || false

dns.valid_suggested_email?
=> true || false
```

### Spliting and Vaildating Emails

The split_email method is used to split the email into three parts
```ruby
email = "test@exmaple.com"
Dnsaur.split_email email
{
  top_level_domain: 'com',         // the top level domain
  domain:           'example.com', // the domain
  address:          'test'         // the address; part before the @ sign
}
```

## Domains
Just like [mailcheck.js](https://github.com/mailcheck/mailcheck), you can and should give Dnsaur
a custom list of domains/top level domains that your user will most likely use to sign up.

This can be done in two different way, ether by giving a completly new list and passing it
into and instance:
```ruby
email = "test@example.com"
domains = ['customdomain.com', 'anotherdomain.net']
top_level_domains = ['com.au', 'ru']

Dnsaur.default_domains = domains
Dnsaur.default_top_level_domains = top_level_domains

Dnsaur.default_domains
=> ["customdomain.com", "anotherdomain.net"]
Dnsaur.default_top_level_domains
=> ["com.au", "ru"]
```

Or if you want to just add values to the default domains provided,
you can pushing new values into the class constants:
```ruby
Dnsaur.default_domains.push('customdomain.com', 'anotherdomain.net')
Dnsaur.default_top_level_domains.push('com.au', 'ru')
```

`default_domains` and `default_top_level_domains` are class members, with one change, all other instances of your class will have your custom list of domains

## Installation

Add this line to your application's Gemfile:

    gem 'dnsaur'

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install dnsaur

## Still left Todo

There is still alot of polish that I would like to do to the code in this gem, and I would
also like to add some more functionality for validating emails:

- More test, and better test for all specs
- RFC822 regexp-based to be able to validate emails. [link](http://ex-parrot.com/~pdw/Mail-RFC822-Address.html)
- Using STMP VRFY command as well as RCTP TO: for better DNS validation
- Improve suggest methods readlity, and usablity

## Contributing

1. Fork it ( https://github.com/[my-github-username]/dnsaur/fork )
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 a new Pull Request