RelativeOrderBase.php

<?php

declare (strict_types=1);
namespace Drupal\Core\Hook\Order;

use Drupal\Core\Hook\OrderOperation\BeforeOrAfter;
use Drupal\Core\Hook\OrderOperation\OrderOperation;

/**
 * Orders an implementation relative to other implementations.
 */
abstract readonly class RelativeOrderBase implements OrderInterface {
    
    /**
     * Constructor.
     *
     * @param list<string> $modules
     *   A list of modules the implementations should order against.
     * @param list<array{class-string, string}> $classesAndMethods
     *   A list of implementations to order against, as [$class, $method].
     */
    public function __construct(array $modules = [], array $classesAndMethods = []) {
        if (!$this->modules && !$this->classesAndMethods) {
            throw new \LogicException('Order must provide either modules or class-method pairs to order against.');
        }
    }
    
    /**
     * Specifies the ordering direction.
     *
     * @return bool
     *   TRUE, if the ordered implementation should be inserted after the
     *   implementations specified in the constructor.
     */
    protected abstract function isAfter() : bool;
    
    /**
     * {@inheritdoc}
     */
    public function getOperation(string $identifier) : OrderOperation {
        return new BeforeOrAfter($identifier, $this->modules, array_map(static fn(array $class_and_method) => implode('::', $class_and_method), $this->classesAndMethods), $this->isAfter());
    }

}