class HelpTopicPluginManager

Same name in this branch
  1. 10 core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\HelpTopicPluginManager
Same name in other branches
  1. 9 core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\HelpTopicPluginManager
  2. 8.9.x core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\HelpTopicPluginManager
  3. 11.x core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\HelpTopicPluginManager
  4. 11.x core/modules/help/src/HelpTopicPluginManager.php \Drupal\help\HelpTopicPluginManager

Provides the default help_topic manager.

Modules and themes can provide help topics in .html.twig files called provider.name_of_topic.html.twig inside the module or theme sub-directory help_topics. The provider is validated to be the extension that provides the help topic.

The Twig file must contain YAML front matter with a key named 'label'. It can also contain keys named 'top_level' and 'related'. For example:


---
label: 'Configuring error responses, including 403/404 pages'

# Related help topics in an array.
related:
  - core.config_basic
  - core.maintenance

# If the value is true then the help topic will appear on admin/help.
top_level: true
---

In addition, modules wishing to add plugins can define them in a module_name.help_topics.yml file, with the plugin ID as the heading for each entry, and these properties:

  • id: The plugin ID.
  • class: The name of your plugin class, implementing \Drupal\help\HelpTopicPluginInterface.
  • top_level: TRUE if the topic is top-level.
  • related: Array of IDs of topics this one is related to.
  • Additional properties that your plugin class needs, such as 'label'.

You can also provide an entry that designates a plugin deriver class in your help_topics.yml file, with a heading giving a prefix ID for your group of derived plugins, and a 'deriver' property giving the name of a class implementing \Drupal\Component\Plugin\Derivative\DeriverInterface. Example:

my_module_prefix:
deriver:
'Drupal\\my_module\\Plugin\\Deriver\\HelpTopicDeriver';

Hierarchy

Expanded class hierarchy of HelpTopicPluginManager

See also

\Drupal\help\HelpTopicDiscovery

\Drupal\help\HelpTopicTwig

\Drupal\help\HelpTopicTwigLoader

\Drupal\help\HelpTopicPluginInterface

\Drupal\help\HelpTopicPluginBase

hook_help_topics_info_alter()

Plugin API

\Drupal\Component\Plugin\Derivative\DeriverInterface

Related topics

1 file declares its use of HelpTopicPluginManager
HelpTopicPluginManager.php in core/modules/help_topics/src/HelpTopicPluginManager.php
1 string reference to 'HelpTopicPluginManager'
help.services.yml in core/modules/help/help.services.yml
core/modules/help/help.services.yml
1 service uses HelpTopicPluginManager
plugin.manager.help_topic in core/modules/help/help.services.yml
Drupal\help\HelpTopicPluginManager

File

core/modules/help/src/HelpTopicPluginManager.php, line 66

Namespace

Drupal\help
View source
class HelpTopicPluginManager extends DefaultPluginManager implements HelpTopicPluginManagerInterface {
    
    /**
     * Provides default values for all help topic plugins.
     *
     * @var array
     */
    protected $defaults = [
        // The plugin ID.
'id' => '',
        // The title of the help topic plugin.
'label' => '',
        // Whether or not the topic should appear on the help topics list.
'top_level' => '',
        // List of related topic machine names.
'related' => [],
        // The class used to instantiate the plugin.
'class' => '',
    ];
    
    /**
     * Constructs a new HelpTopicManager object.
     *
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     * @param \Drupal\Core\Extension\ThemeHandlerInterface $themeHandler
     *   The theme handler.
     * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
     *   Cache backend instance to use.
     * @param string $root
     *   The app root.
     */
    public function __construct(ModuleHandlerInterface $module_handler, ThemeHandlerInterface $themeHandler, CacheBackendInterface $cache_backend, string $root) {
        // Note that the parent construct is not called because this class does not use
        // annotated class discovery.
        $this->moduleHandler = $module_handler;
        $this->alterInfo('help_topics_info');
        $this->setCacheBackend($cache_backend, 'help_topics');
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getDiscovery() {
        if (!isset($this->discovery)) {
            $module_directories = $this->moduleHandler
                ->getModuleDirectories();
            $all_directories = array_merge([
                'core' => $this->root . '/core',
            ], $module_directories, $this->themeHandler
                ->getThemeDirectories());
            // Search for Twig help topics in subdirectory help_topics, under
            // modules/profiles, themes, and the core directory.
            $all_directories = array_map(function ($dir) {
                return [
                    $dir . '/help_topics',
                ];
            }, $all_directories);
            $discovery = new HelpTopicDiscovery($all_directories);
            // Also allow modules/profiles to extend help topic discovery to their
            // own plugins and derivers, in my_module.help_topics.yml files.
            $discovery = new YamlDiscoveryDecorator($discovery, 'help_topics', $module_directories);
            $discovery = new ContainerDerivativeDiscoveryDecorator($discovery);
            $this->discovery = $discovery;
        }
        return $this->discovery;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function providerExists($provider) {
        return $this->moduleHandler
            ->moduleExists($provider) || $this->themeHandler
            ->themeExists($provider);
    }
    
    /**
     * {@inheritdoc}
     */
    protected function findDefinitions() {
        $definitions = parent::findDefinitions();
        // At this point the plugin list only contains valid plugins. Ensure all
        // related plugins exist and the relationship is bi-directional. This
        // ensures topics are listed on their related topics.
        foreach ($definitions as $plugin_id => $plugin_definition) {
            foreach ($plugin_definition['related'] as $key => $related_id) {
                // If the related help topic does not exist it might be for a module
                // that is not installed. Remove it.
                // @todo Discuss this more as this could cause silent errors but it
                //   offers useful functionality to relate to a help topic provided by
                //   extensions that are yet to be installed.
                //   https://www.drupal.org/i/3360133
                if (!isset($definitions[$related_id])) {
                    unset($definitions[$plugin_id]['related'][$key]);
                    continue;
                }
                // Make the related relationship bi-directional.
                if (isset($definitions[$related_id]) && !in_array($plugin_id, $definitions[$related_id]['related'], TRUE)) {
                    $definitions[$related_id]['related'][] = $plugin_id;
                }
            }
        }
        return $definitions;
    }

}

Members

Title Sort descending Modifiers Object type Summary Overriden Title Overrides
DefaultPluginManager::$additionalAnnotationNamespaces protected property Additional annotation namespaces.
DefaultPluginManager::$alterHook protected property Name of the alter hook if one should be invoked.
DefaultPluginManager::$cacheKey protected property The cache key.
DefaultPluginManager::$cacheTags protected property An array of cache tags to use for the cached definitions.
DefaultPluginManager::$moduleExtensionList protected property The module extension list.
DefaultPluginManager::$moduleHandler protected property The module handler to invoke the alter hook. 1
DefaultPluginManager::$namespaces protected property An object of root paths that are traversable.
DefaultPluginManager::$pluginDefinitionAnnotationName protected property The name of the annotation that contains the plugin definition.
DefaultPluginManager::$pluginDefinitionAttributeName protected property The name of the attribute that contains the plugin definition.
DefaultPluginManager::$pluginInterface protected property The interface each plugin should implement. 1
DefaultPluginManager::$subdir protected property The subdirectory within a namespace to look for plugins.
DefaultPluginManager::alterDefinitions protected function Invokes the hook to alter the definitions if the alter hook is set. 5
DefaultPluginManager::alterInfo protected function Sets the alter hook name.
DefaultPluginManager::clearCachedDefinitions public function Clears static and persistent plugin definition caches. Overrides CachedDiscoveryInterface::clearCachedDefinitions 11
DefaultPluginManager::extractProviderFromDefinition protected function Extracts the provider from a plugin definition.
DefaultPluginManager::getCacheContexts public function The cache contexts associated with this object. Overrides CacheableDependencyInterface::getCacheContexts
DefaultPluginManager::getCachedDefinitions protected function Returns the cached plugin definitions of the decorated discovery class.
DefaultPluginManager::getCacheMaxAge public function The maximum age for which this object may be cached. Overrides CacheableDependencyInterface::getCacheMaxAge
DefaultPluginManager::getCacheTags public function The cache tags associated with this object. Overrides CacheableDependencyInterface::getCacheTags
DefaultPluginManager::getDefinitions public function Gets the definition of all plugins for this type. Overrides DiscoveryTrait::getDefinitions 2
DefaultPluginManager::getFactory protected function Gets the plugin factory. Overrides PluginManagerBase::getFactory
DefaultPluginManager::processDefinition public function Performs extra processing on plugin definitions. 14
DefaultPluginManager::setCacheBackend public function Initialize the cache backend.
DefaultPluginManager::setCachedDefinitions protected function Sets a cache of plugin definitions for the decorated discovery class.
DefaultPluginManager::useCaches public function Disable the use of caches. Overrides CachedDiscoveryInterface::useCaches 1
DiscoveryCachedTrait::$definitions protected property Cached definitions array. 1
DiscoveryCachedTrait::getDefinition public function Overrides DiscoveryTrait::getDefinition 3
DiscoveryTrait::doGetDefinition protected function Gets a specific plugin definition.
DiscoveryTrait::hasDefinition public function
HelpTopicPluginManager::$defaults protected property Provides default values for all help topic plugins. Overrides DefaultPluginManager::$defaults
HelpTopicPluginManager::findDefinitions protected function Finds plugin definitions. Overrides DefaultPluginManager::findDefinitions
HelpTopicPluginManager::getDiscovery protected function Gets the plugin discovery. Overrides DefaultPluginManager::getDiscovery
HelpTopicPluginManager::providerExists protected function Determines if the provider of a definition exists. Overrides DefaultPluginManager::providerExists
HelpTopicPluginManager::__construct public function Constructs a new HelpTopicManager object. Overrides DefaultPluginManager::__construct
PluginManagerBase::$discovery protected property The object that discovers plugins managed by this manager.
PluginManagerBase::$factory protected property The object that instantiates plugins managed by this manager.
PluginManagerBase::$mapper protected property The object that returns the preconfigured plugin instance appropriate for a particular runtime condition.
PluginManagerBase::createInstance public function 15
PluginManagerBase::getFallbackPluginId protected function Gets a fallback id for a missing plugin. 6
PluginManagerBase::getInstance public function 6
PluginManagerBase::handlePluginNotFound protected function Allows plugin managers to specify custom behavior if a plugin is not found. 1
UseCacheBackendTrait::$cacheBackend protected property Cache backend instance.
UseCacheBackendTrait::$useCaches protected property Flag whether caches should be used or skipped.
UseCacheBackendTrait::cacheGet protected function Fetches from the cache backend, respecting the use caches flag.
UseCacheBackendTrait::cacheSet protected function Stores data in the persistent cache, respecting the use caches flag.

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