UpdateManagerAccessCheck.php

<?php

namespace Drupal\update\Access;

use Drupal\Core\Access\AccessResult;
use Drupal\Core\Routing\Access\AccessInterface;
use Drupal\Core\Site\Settings;

/**
 * Determines whether allow authorized operations is set.
 */
class UpdateManagerAccessCheck implements AccessInterface {
    
    /**
     * Settings Service.
     *
     * @var \Drupal\Core\Site\Settings
     */
    protected $settings;
    
    /**
     * Constructs an UpdateManagerAccessCheck object.
     *
     * @param \Drupal\Core\Site\Settings $settings
     *   The read-only settings container.
     */
    public function __construct(Settings $settings) {
        $this->settings = $settings;
    }
    
    /**
     * Checks access.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    public function access() {
        // Uncacheable because the access result depends on a Settings key-value
        // pair, and can therefore change at any time.
        return AccessResult::allowedIf($this->settings
            ->get('allow_authorize_operations', TRUE))
            ->setCacheMaxAge(0);
    }

}