RequiredWhen.php

<?php
declare(strict_types=1);

namespace Sirius\Validation\Rule;

class RequiredWhen extends Required
{
    const OPTION_ITEM = 'item';
    const OPTION_RULE = 'rule';
    const OPTION_RULE_OPTIONS = 'rule_options';

    const MESSAGE = 'This field is required';
    const LABELED_MESSAGE = '{label} is required';

    public function getItemRule(): ?AbstractRule
    {
        $rule = false;
        $ruleOptions = (isset($this->options[self::OPTION_RULE_OPTIONS])) ?
            (array)$this->options[self::OPTION_RULE_OPTIONS] :
            [];

        if (is_string($this->options[self::OPTION_RULE])) {
            $ruleClass = $this->options[self::OPTION_RULE];
            if (class_exists($ruleClass)) {
                $rule = new $ruleClass($ruleOptions);
            } elseif (class_exists('Sirius\\Validation\\Rule\\' . $ruleClass)) {
                $ruleClass = 'Sirius\\Validation\\Rule\\' . $ruleClass;
                $rule = new $ruleClass($ruleOptions);
            }
        } elseif (is_object($this->options[self::OPTION_RULE])
            && $this->options[self::OPTION_RULE] instanceof AbstractRule
        ) {
            $rule = $this->options[self::OPTION_RULE];
        }
        if (!$rule) {
            throw new \InvalidArgumentException(
                'Validator for the other item is not valid or cannot be constructed based on the data provided'
            );
        }
        /* @var $rule AbstractRule */
        $rule->setContext($this->context ?? []); // @phpstan-ignore-line

        return $rule; // @phpstan-ignore-line
    }

    public function validate(mixed $value, ?string $valueIdentifier = null): bool
    {
        $this->value = $value;

        if (!isset($this->options[self::OPTION_ITEM])) {
            $this->success = true;
        } else {
            $relatedItemPath = $this->getRelatedValueIdentifier((string)$valueIdentifier, $this->options[self::OPTION_ITEM]);
            $relatedItemValue = $this->context && $relatedItemPath !== null ? $this->context->getItemValue($relatedItemPath) : null;

            $itemRule = $this->getItemRule();
            if ($itemRule && $itemRule->validate($relatedItemValue, $relatedItemPath)) {
                $this->success = ($value !== null && (!is_string($value) || trim($value) !== ''));
            } else {
                $this->success = true;
            }
        }

        return $this->success;
    }
}