HookHelpSection.php

<?php

namespace Drupal\help\Plugin\HelpSection;

use Drupal\Core\Extension\ModuleHandlerInterface;
use Drupal\Core\Link;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides the module topics list section for the help page.
 *
 * @HelpSection(
 *   id = "hook_help",
 *   title = @Translation("Module overviews"),
 *   description = @Translation("Module overviews are provided by modules. Overviews available for your installed modules:"),
 * )
 */
class HookHelpSection extends HelpSectionPluginBase implements ContainerFactoryPluginInterface {
    
    /**
     * The module handler.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * Constructs a HookHelpSection object.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler service.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, ModuleHandlerInterface $module_handler) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('module_handler'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function listTopics() {
        $topics = [];
        $this->moduleHandler
            ->invokeAllWith('help', function (callable $hook, string $module) use (&$topics) {
            $title = $this->moduleHandler
                ->getName($module);
            $topics[$title] = Link::createFromRoute($title, 'help.page', [
                'name' => $module,
            ]);
        });
        // Sort topics by title, which is the array key above.
        ksort($topics);
        return $topics;
    }

}