How to (Easily) Create a Custom Validation Rule

By: Povilas Korop

For some reason, only now I’ve found out about a feature that was introduced in Laravel 5.5 – artisan command that makes your validation rule, similar to Request classes. Let’s see it in action.

Let’s take an example of a form to fill in Summer Olympic Games events – so year and city:

laravel form

Now, let’s create a validation rule that you can enter only the year of Olympic Games:

Games started in 1896
Year can’t be bigger than current year
Number should be divided by 4

Let’s run a command:


php artisan make:rule OlympicYear

php artisan make:rule OlympicYear

Laravel generates a file app/Rules/OlympicYear.php:


namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class OlympicYear implements Rule
{

    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        //
    }

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

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;

class OlympicYear implements Rule

{

/**

* Determine if the validation rule passes.

* @param string $attribute

* @param mixed $value

* @return bool

public function passes($attribute, $value)

{

}

/**

* Get the validation error message.

* @return string

public function message()

{

return 'The validation error message.';

}

As I said, it’s similar to Requests classes for validation. We fill in the methods. passes() should return true/false depending on $value condition, which is this in our case:


public function passes($attribute, $value)
{
    return $value >= 1896 && $value <= date('Y') && $value % 4 == 0;
}

public function passes($attribute, $value)

{

return $value >= 1896 && $value <= date('Y') && $value % 4 == 0;

}

Next, we fill in the error message to be this:


public function message()
{
    return ':attribute should be a year of Olympic Games';
}

public function message()

{

return ':attribute should be a year of Olympic Games';

}

Finally, how we use this class? In controller’s store() method we have this code:


public function store(Request $request)
{
    $this->validate($request, ['year' => new OlympicYear]);
}

public function store(Request $request)

{

$this->validate($request, ['year' => new OlympicYear]);

}

Pay attention to syntax, second parameter should be an array and then we create a new object from our Rule class.
That’s it!

Laravel validation custom

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E-mail: povilas@laraveldaily.com
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5 thoughts on “How to (Easily) Create a Custom Validation Rule”

Yusup says:

May 30, 2018 at 6:26 pm

That’s good, but I got used to Requests

Reply
1. Nerijus says:
  
  May 31, 2018 at 9:35 am
  
  You can use custom validation rules in requests also
  
  Reply
Jorge Costa says:

May 30, 2018 at 7:16 pm

I think you got a code error in $this->validate($request, [‘year’ => new OddNumber]);
should be $this->validate($request, [‘year’ => new OlympicYear]);

Cheers

Reply
1. Povilas Korop says:
  
  May 30, 2018 at 7:21 pm
  
  Thanks a lot Jorge! Indeed was testing with a few different classes before writing the article. Fixed now.
  
  Reply
rajiv bikram says:

June 8, 2018 at 6:43 pm

That’s good, but I got used to Requests. Thank you for sharing.

Reply

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