symfony/property-access 6.4.6 breaks magic methods

[boonkerz]

Symfony version(s) affected

6.4.6

Description

6.4.6 break magic methods.

How to reproduce

class test
{

    private array $tests = [];


    public function __get(string $name): mixed
    {
        return $this->tests[$name]?? null;
    }

    public function __set(string $name, mixed $value): void
    {
        $this->tests[$name] = $value;
    }
}


$test = new test();
$propertyAccessor = new PropertyAccessor();
var_dump($propertyAccessor->getValue($test, 'Wouter'));

6.4.4 return null
6.4.6 return Can't get a way to read the property "Wouter" in class "test"

Possible Solution

No response

Additional Context

No response

[xabbuh]

Looks like your class is missing the implementation of the __isset() method:

public function __isset(string $name): bool
{
    return null !== ($this->tests[$name] ?? null);
}

[boonkerz]

class test
{

    private array $tests = [];

    public function __get(string $name): mixed
    {
        return $this->tests[$name]?? null;
    }

    public function __set(string $name, mixed $value): void
    {
        $this->tests[$name] = $value;
    }

    public function __isset(string $name): bool
    {
        return null !== ($this->tests[$name]?? null);
    }
}


$test = new test();
$propertyAccessor = new PropertyAccessor();
var_dump($propertyAccessor->getValue($test, 'Wouter'));

this does not help to fix the behaviour.

returns the same error.

[boonkerz]

Here is the Code

https://phpsandbox.io/n/propertyaccess-fipnm

[bastien-effetb]

Same problem here

[n0rbyt3]

There is an updated check for non-initialized properties which causes the issue:

symfony/src/Symfony/Component/PropertyAccess/PropertyAccessor.php

Lines 414 to 426 in b7eb42e

	if (!isset($object->$name) && !\array_key_exists($name, (array) $object)) {
	try {
	$r = new \ReflectionProperty($class, $name);
	if ($r->isPublic() && !$r->hasType()) {
	throw new UninitializedPropertyException(sprintf('The property "%s::$%s" is not initialized.', $class, $name));
	}
	} catch (\ReflectionException $e) {
	if (!$ignoreInvalidProperty) {
	throw new NoSuchPropertyException(sprintf('Can\'t get a way to read the property "%s" in class "%s".', $property, $class));
	}
	}
	}

Your magic __get() method can handle uninitialized properties by returning null. Adding this __isset() method resolves the issue:

public function __isset(string $name): bool
{
  return true;
}

[boonkerz]

yea that works but this is not obvious.
the docs does not say anything about this new behaviour
https://symfony.com/doc/current/components/property_access.html#magic-get-method
and its differ from the previous version.

[n0rbyt3]

Indeed, it's just a workaround.

Friendly ping @nicolas-grekas who changed the implementation in commit 9610a7c. An __isset() implementation has been added to the TestClassMagicGet fixture which is a BC break.

I don't see any reason why this additional check exists. IMO, it's part of the PropertyTypeExtractorInterface to detect if the property is accessible. The ReflectionExtractor inside the PropertyInfo component does all the reflection logic so there should be no need to reflect the property again - even if another PropertyTypeExtractorInterface implementation is used. Otherwise PropertyReadInfo should be extended to return more details for the PropertyAccessor.

[k0d3r1s]

i will add this here:
property-access 6.4.6 and 6.4.7 breaks doctrine migrations diff, going back to 6.4.4 fixes the issue

[derrabus]

@k0d3r1s Please open a new issue with a detailed reproducer.

[aesislabs]

Same problem here, it break my applications

[nicolas-grekas]

That's because you're missing an implementation for __isset. While property access was tolerant to this, this breaks the behavior of objects with the php engine.

[netsuo]

I have no problem with that, but maybe it needs some doc update

[nicolas-grekas]

Maybe a note in the UPGRADE-6.4.md file? Up for a PR?

[boonkerz]

@nicolas-grekas the examples on https://symfony.com/doc/current/components/property_access.html#magic-get-method should be fixed