class HelpTopicPluginManager in Drupal 8

Same name and namespace in other branches

9 core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\HelpTopicPluginManager
10 core/modules/help_topics/src/HelpTopicPluginManager.php \Drupal\help_topics\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_topics\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:

mymodule_prefix:
deriver:
'Drupal\\mymodule\\Plugin\\Deriver\\HelpTopicDeriver';

@internal Help Topics is currently experimental and should only be leveraged by experimental modules and development releases of contributed modules. See https://www.drupal.org/core/experimental for more information.

Hierarchy

class \Drupal\Component\Plugin\PluginManagerBase implements PluginManagerInterface uses DiscoveryTrait
- class \Drupal\Core\Plugin\DefaultPluginManager implements CachedDiscoveryInterface, PluginManagerInterface, CacheableDependencyInterface uses DiscoveryCachedTrait, UseCacheBackendTrait
  - class \Drupal\help_topics\HelpTopicPluginManager implements HelpTopicPluginManagerInterface

Expanded class hierarchy of HelpTopicPluginManager

File

core/modules/help_topics/src/HelpTopicPluginManager.php, line 69

Namespace

Drupal\help_topics

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' => '',
  ];

  /**
   * The theme handler.
   *
   * @var \Drupal\Core\Extension\ThemeHandlerInterface
   */
  protected $themeHandler;

  /**
   * The app root.
   *
   * @var string
   */
  protected $root;

  /**
   * Constructs a new HelpTopicManager object.
   *
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler.
   * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
   *   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 $theme_handler, CacheBackendInterface $cache_backend, $root) {

    // Note that the parent construct is not called because this not use
    // annotated class discovery.
    $this->moduleHandler = $module_handler;
    $this->themeHandler = $theme_handler;
    $this
      ->alterInfo('help_topics_info');

    // Use the 'config:core.extension' cache tag so the plugin cache is
    // invalidated on theme install and uninstall.
    $this
      ->setCacheBackend($cache_backend, 'help_topics', [
      'config:core.extension',
    ]);
    $this->root = (string) $root;
  }

  /**
   * {@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 mymodule.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 help topic provided by
        //   extensions that are yet to be installed.
        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

Name	Modifiers	Type	Description	Overrides
DefaultPluginManager::$additionalAnnotationNamespaces	protected	property	Additional namespaces the annotation discovery mechanism should scan for annotation definitions.
DefaultPluginManager::$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::$moduleHandler	protected	property	The module handler to invoke the alter hook.	1
DefaultPluginManager::$namespaces	protected	property	An object that implements \Traversable which contains the root paths keyed by the corresponding namespace to look for plugin implementations.
DefaultPluginManager::$pluginDefinitionAnnotationName	protected	property	The name of the annotation that contains the plugin definition.
DefaultPluginManager::$pluginInterface	protected	property	The interface each plugin should implement.	1
DefaultPluginManager::$subdir	protected	property	The subdirectory within a namespace to look for plugins, or FALSE if the plugins are in the top level of the namespace.
DefaultPluginManager::alterDefinitions	protected	function	Invokes the hook to alter the definitions if the alter hook is set.	1
DefaultPluginManager::alterInfo	protected	function	Sets the alter hook name.
DefaultPluginManager::clearCachedDefinitions	public	function	Clears static and persistent plugin definition caches. Overrides CachedDiscoveryInterface::clearCachedDefinitions	5
DefaultPluginManager::extractProviderFromDefinition	protected	function	Extracts the provider from a plugin definition.
DefaultPluginManager::fixContextAwareDefinitions	private	function	Fix the definitions of context-aware plugins.
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.	13
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::$root	protected	property	The app root.
HelpTopicPluginManager::$themeHandler	protected	property	The theme handler.
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::$mapper	protected	property	The object that returns the preconfigured plugin instance appropriate for a particular runtime condition.
PluginManagerBase::createInstance	public	function	Creates a pre-configured instance of a plugin. Overrides FactoryInterface::createInstance	12
PluginManagerBase::getInstance	public	function	Gets a preconfigured instance of a plugin. Overrides MapperInterface::getInstance	7
PluginManagerBase::handlePluginNotFound	protected	function	Allows plugin managers to specify custom behavior if a plugin is not found.	1
UseCacheBackendTrait::$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.	1
UseCacheBackendTrait::cacheSet	protected	function	Stores data in the persistent cache, respecting the use caches flag.

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class HelpTopicPluginManager in Drupal 8

Hierarchy

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