Symfony验证器模块无法自动加载注释

Question

I am running symfony/validator v3.4.4 standalone and am trying to validate objects and am running into an error where doctrine is unable to locate the validation annotation classes.

What am I missing?

use Symfony\Component\Validator\Validation;
use Symfony\Component\Validator\Constraints as Assert;

require_once('vendor/autoload.php');

$validator = Validation::createValidatorBuilder()
    ->enableAnnotationMapping()
    ->getValidator();


class Foo {

    /**
     * @Assert\NotBlank()
     */
    public $userId;

    function __construct($userId) {
        $this->userId = $userId;
    }
}

class Bar {}

$foo = new Foo(1);
$bar = new Bar();

var_dump($validator->validate($bar));

/** 
 * =>
 * object(Symfony\Component\Validator\ConstraintViolationList)#22 (1) {
 * ["violations":"Symfony\Component\Validator\ConstraintViolationList":private]=>
 *  array(0) {
 * }
 * }
 */

var_dump($validator->validate($foo));

/**
 * =>
 * Fatal error: Uncaught exception
 * 'Doctrine\Common\Annotations\AnnotationException'
 * with message '[Semantical Error] The annotation
 * "@Symfony\Component\Validator\Constraints\NotBlank" in property Foo::$userId
 * does not exist, or could not be auto-loaded.' in
 * /home/readitla/vendor/doctrine/annotations/lib/Doctrine/Common/Annotations/AnnotationException.php:54
 */

Thanks in advance

Answer 1

I've had the same error before in tests where I wanted to pass the actual validator instead of a mock.

The problem can be fixed by calling class_exists(Assert\\NotBlank::class) :

<?php

use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\Validator\Validation;

require_once __DIR__ . '/vendor/autoload.php';

class_exists(Assert\NotBlank::class);

$validator = Validation::createValidatorBuilder()
    ->enableAnnotationMapping()
    ->getValidator();

class Foo
{
    /**
     * @Assert\NotBlank()
     */
    public $id;
}

$foo = new Foo();
$foo->id = 123;

var_dump($validator->validate($foo));
/*
object(Symfony\Component\Validator\ConstraintViolationList)#20 (1) {
  ["violations":"Symfony\Component\Validator\ConstraintViolationList":private]=>
  array(0) {
  }
}
*/

I'm not exactly sure why this happens, but for some reason registering the class in the autoloader is not enough. It seems that annotations do not trigger them to be autoloaded or something like that.