Laravel eloquent rule for domain name

Question

Is there any specific rule for domain name? Was googling for about an hour, but didn't get the list of rules. I've tried "domain" => "required|url" but it's requering a protocol type in it, so it's not the best option for me.

Answer 1

I use a custom rule to check for valid FQDN.

Got the regex from another answer here @ SO, see: fully-qualified-domain-name-validation

One of the answers provides a regex, with example:

/^(?!:\/\/)(?=.{1,255}$)((.{1,63}\.){1,127}(?![0-9]*$)[a-z0-9-]+\.?)$/i

With a demo: http://regexr.com/3g5j0 which shows you the matches.

Laravel 5.5

I then created a custom rule:

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class FQDN implements Rule
{
    /**
     * Create a new rule instance.
     *
     * @return void
     */
    public function __construct()
    {
        //
    }

    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        return preg_match('/^(?!:\/\/)(?=.{1,255}$)((.{1,63}\.){1,127}(?![0-9]*$)[a-z0-9-]+\.?)$/i', $value);
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return 'Invalid FQDN.';
    }
}

And used it like this:

// ...
use App\Rules\FQDN;

// ...
$this->validate($request, [
    // other rules be here
    'fqdn' => [
        'required',
        new FQDN(),
    ],
]);

Edit for Laravel 5.4

In Laravel 5.4 you do not have the Rule contract, you can extend the validator in the AppServiceProvider, see here (or create a separate ExtendedValidationServiceProvider).

You can do this inline, but I prefer having separate classes for this.

In the ServiceProvider boot method, add:

use Illuminate\Support\Facades\Validator;

// ...

public function boot()
{
    Validator::extend('fqdn', 'App\Rules\FQDN@validate');
    Validator::replacer('fqdn', 'App\Rules\FQDN@replace');
}

Validator::extend() is for the validation rule

Validator::replacer() is for the error message

Then for the 5.4 rule class:

<?php

namespace App\Rules;

class FQDN
{
    public function validate($attribute, $value, $parameters, $validator)
    {
        return preg_match('/^(?!:\/\/)(?=.{1,255}$)((.{1,63}\.){1,127}(?![0-9]*$)[a-z0-9-]+\.?)$/i', $value);
    }

    public function replace($message, $attribute, $rule, $parameters)
    {
        return str_replace(':fqdn', implode(', ', $parameters), $message);
    }
}

Now you can use your validation like:

$this->validate($request, [
    // other rules be here
    'fqdn' => [
        'required',
        'fqdn',
    ],
]);