AbstractLocalDataEventSubscriber.php

<?php

declare(strict_types=1);

namespace Dbp\Relay\CoreBundle\LocalData;

use Dbp\Relay\CoreBundle\Authorization\AbstractAuthorizationService;
use Dbp\Relay\CoreBundle\Exception\ApiError;
use Symfony\Component\Config\Definition\Builder\NodeDefinition;
use Symfony\Component\Config\Definition\Builder\TreeBuilder;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Contracts\EventDispatcher\Event;

/*
 * Abstract implementation of a configurable local data provider post event subscriber.
 * It is intended to be derived by local data aware entity post event subscribers.
 * A mapping between source attribute and local data attribute,
 * and default values for the attributes can be specified by means of the deriving event subscriber's bundle config.
 * If no default value is specified, an exception is thrown in the case the mapped source attribute is not found.
 */
abstract class AbstractLocalDataEventSubscriber extends AbstractAuthorizationService implements EventSubscriberInterface
{
    protected const ROOT_CONFIG_NODE = 'local_data_mapping';
    protected const SOURCE_ATTRIBUTE_CONFIG_NODE = 'source_attribute';
    protected const LOCAL_DATA_ATTRIBUTE_CONFIG_NODE = 'local_data_attribute';
    protected const AUTHORIZATION_EXPRESSION_CONFIG_NODE = 'authorization_expression';
    protected const ALLOW_LOCAL_QUERY_CONFIG_NODE = 'allow_query';
    protected const DEFAULT_VALUE_ATTRIBUTE_CONFIG_NODE = 'default_value';
    protected const DEFAULT_VALUES_ATTRIBUTE_CONFIG_NODE = 'default_values';

    private const SOURCE_ATTRIBUTE_KEY = 'source';
    private const DEFAULT_VALUE_KEY = 'default';
    private const QUERYABLE_KEY = 'queryable';

    /*
     * WORKAROUND: could not find a way to determine whether a Symfony config array node was NOT specified since it provides an empty
     * array in case it is not specified. So I use an array value as default which does not seem to be reproducible by the configurator.
     */
    private const ARRAY_VALUE_NOT_SPECIFIED = [null => null];

    /** @var array */
    private $attributeMapping;

    public function __construct()
    {
        $this->attributeMapping = [];
    }

    public function setConfig(array $config)
    {
        $configNode = $config[self::ROOT_CONFIG_NODE] ?? [];
        $rightExpressions = [];

        foreach ($configNode as $configMappingEntry) {
            $localDataAttributeName = $configMappingEntry[self::LOCAL_DATA_ATTRIBUTE_CONFIG_NODE];

            if (isset($this->attributeMapping[$localDataAttributeName])) {
                throw new \RuntimeException(sprintf('multiple mapping entries for local data attribute %s', $localDataAttributeName));
            }

            $attributeMapEntry = [];
            $attributeMapEntry[self::SOURCE_ATTRIBUTE_KEY] = $configMappingEntry[self::SOURCE_ATTRIBUTE_CONFIG_NODE];
            $attributeMapEntry[self::QUERYABLE_KEY] = $configMappingEntry[self::ALLOW_LOCAL_QUERY_CONFIG_NODE];

            $defaultValue = $configMappingEntry[self::DEFAULT_VALUE_ATTRIBUTE_CONFIG_NODE] ?? null;
            if ($defaultValue === null) {
                $defaultArray = $configMappingEntry[self::DEFAULT_VALUES_ATTRIBUTE_CONFIG_NODE] ?? null;
                if ($defaultArray !== null && $defaultArray !== self::ARRAY_VALUE_NOT_SPECIFIED) {
                    $defaultValue = $defaultArray;