Handle Entity classes with Symfony Validator component

I'm trying to use symfony/validator outside of Symfony by just installing composer require symfony/validator (vemphasized text7.1)

Following this guide https://symfony.com/doc/current/components/validator.html

I now have:

$validator = Validation::createValidator();
$violations = $validator->validate($someName, [
    new Length(['min' => 10]),
    new NotBlank(),
]);

This validation works fine.

But I would like validation like in this guide: https://symfony.com/doc/current/validation.html So that I can validate something like this:

// src/Entity/Author.php
<?php

namespace App\Entity;

use Symfony\Component\Validator\Constraints as Assert;

class Author
{
    #[Assert\NotBlank]
    public string $name;
}

When I now try to validate it $violations is always 0 even if the name is null

    $author = new Author();
    $author->name = null;
    $validator = Validation::createValidator();
    $violations = $validator->validate($author);

The documentation isn't very clear on this but it looks like the standalone version is incapable of handling a class like this.

Is something like this possible with the standalone version?

Turned out that creating function that does the same trick wasn't that hard to make:

function validateEntity($entity)
{
    $class = new ReflectionClass($entity);

    $validator = Validation::createValidator();

    $violations = [];
    $properties = $class->getProperties();
    foreach ($properties as $property) {
        $propertyName = $property->getName();
        $attributes = $property->getAttributes();
        $constraints = [];
        foreach ($attributes as $attribute) {
            $constraints[] = $attribute->newInstance();
        }

        try {
            $value = $entity->$propertyName;
        }
        catch(Error $err) {
            $value = null;
        }
        $propertyViolations = $validator->validate($value, $constraints);
        if (count($propertyViolations)) {
            $violations[$propertyName] = $propertyViolations;
        }
    }
    return $violations;
}

Call it like

$author = new Author();
$violations = validateEntity($author);

I only needed it for simple entities so not sure if it works well for more complicated situations.