Custom rules

You can also create and use your own rules. To do this, you will need to create a rule and an exception to go with the rule.

To create a rule, you need to create a class that extends the AbstractRule class and is within the Rules namespace. When the rule is called the logic inside the validate method will be executed. Here's how the class should look:

namespace My\Validation\Rules;

use Respect\Validation\Rules\AbstractRule;

final class Something extends AbstractRule
{
    public function validate($input): bool
    {
        // Do something here with the $input and return a boolean value
    }
}

Each rule must have an Exception to go with it. Exceptions should be named with the name of the rule followed by the word Exception. The process of creating an Exception is similar to creating a rule but there are no methods in the Exception class. Instead, you create one static property that includes an array with the information below:

namespace My\Validation\Exceptions;

use Respect\Validation\Exceptions\ValidationException;

final class SomethingException extends ValidationException
{
    protected $defaultTemplates = [
        self::MODE_DEFAULT => [
            self::STANDARD => 'Validation message if Something fails validation.',
        ],
        self::MODE_NEGATIVE => [
            self::STANDARD => 'Validation message if the negative of Something is called and fails validation.',
        ],
    ];
}

So in the end, the folder structure for your Rules and Exceptions should look something like the structure below. Note that the folders (and namespaces) are plural but the actual Rules and Exceptions are singular.

My
 +-- Validation
     +-- Exceptions
         +-- SomethingException.php
     +-- Rules
         +-- Something.php

All classes in Validation are created by the Factory class. If you want Validation to execute your rule (or rules) in the chain, you must overwrite the default Factory.

Factory::setDefaultInstance(
    (new Factory())
        ->withRuleNamespace('My\\Validation\\Rules')
        ->withExceptionNamespace('My\\Validation\\Exceptions')
);
v::something(); // Try to load "My\Validation\Rules\Something" if any