Abstract validator creates warning when an array value contains circular reference

[michalbundyra]

As the \Zend\Validator\AbstractValidator::createMessage method uses var_export to convert arrays to strings this fails if the array contains a circular reference. The problem line is https://github.com/zendframework/zend-validator/blob/master/src/AbstractValidator.php#L294.

I've provided a quick example of this below which outputs "PHP Warning: var_export does not handle circular references":

class ExampleValidator extends \Zend\Validator\AbstractValidator
{
    protected $messageTemplates = [
        'someError' => 'error'
    ];
    public function isValid($value)
    {
        $this->setValue($value);
        $this->error('someError');
        return false;
    }
}

class Circular {
    public $reference;
}

$test = new Circular();
$test->reference = $test;

$validator = new ExampleValidator();
$validator->isValid([$test]);

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Originally posted by @tomp4l at zendframework/zend-validator#82

[michalbundyra]

Can you avoid the circular dependency?

To be honest I don't think we will implement some kind of circular depedency check because it could affect to the performance.

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Originally posted by @Maks3w at zendframework/zend-validator#82 (comment)

[michalbundyra]

I've worked around it by handling the array to string conversion manually by overriding setValue. This may cause issues with built in validators provided by Zend but it's only a minor inconvenience for my use case.

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Originally posted by @tomp4l at zendframework/zend-validator#82 (comment)