Issue #2234439 by jhodgdon, cosmicdreams, xjm: Add a section for the plugin...

Issue #2234439 by jhodgdon, cosmicdreams, xjm: Add a section for the plugin system to the API doc landing page.

core/lib/Drupal/Component/Annotation/Plugin.php

@@ -18,6 +18,8 @@
  * of a class to be located with the class itself, rather than in module-based
  * info hooks.
  *
+ * @ingroup plugin_api
+ *
  * @Annotation
  */
 class Plugin implements AnnotationInterface {

core/lib/Drupal/Component/Plugin/ConfigurablePluginInterface.php

@@ -9,6 +9,8 @@
 
 /**
  * Provides an interface for a configurable plugin.
+ *
+ * @ingroup plugin_api
  */
 interface ConfigurablePluginInterface {
 

core/lib/Drupal/Component/Plugin/ContextAwarePluginInterface.php

@@ -14,6 +14,8 @@
  *
  * Context aware plugins can specify an array of context definitions keyed by
  * context name at the plugin definition under the "context" key.
+ *
+ * @ingroup plugin_api
  */
 interface ContextAwarePluginInterface extends PluginInspectionInterface {
 

core/lib/Drupal/Component/Plugin/Derivative/DerivativeInterface.php

@@ -9,6 +9,8 @@
 
 /**
  * Plugin interface for derivative plugin handling.
+ *
+ * @ingroup plugin_api
  */
 interface DerivativeInterface {
 

core/lib/Drupal/Component/Plugin/Discovery/DiscoveryInterface.php

@@ -10,6 +10,8 @@
 /**
  * An interface defining the minimum requirements of building a plugin
  * discovery component.
+ *
+ * @ingroup plugin_api
  */
 interface DiscoveryInterface {
 

core/lib/Drupal/Component/Plugin/PluginBag.php

@@ -9,6 +9,8 @@
 
 /**
  * Defines an object which stores multiple plugin instances to lazy load them.
+ *
+ * @ingroup plugin_api
  */
 abstract class PluginBag implements \Iterator, \Countable {
 

core/lib/Drupal/Component/Plugin/PluginInspectionInterface.php

@@ -11,6 +11,8 @@
  *
  * This interface provides some simple tools for code receiving a plugin to
  * interact with the plugin system.
+ *
+ * @ingroup plugin_api
  */
 interface PluginInspectionInterface {
 

core/lib/Drupal/Component/Plugin/PluginManagerInterface.php

@@ -26,6 +26,8 @@
  * class, which contains the proxying logic.
  *
  * @see \Drupal\Component\Plugin\PluginManagerBase
+ *
+ * @ingroup plugin_api
  */
 interface PluginManagerInterface extends DiscoveryInterface, FactoryInterface, MapperInterface {
 }

core/lib/Drupal/Core/Entity/EntityWithPluginBagsInterface.php

@@ -11,6 +11,8 @@
  * Provides an interface for an object utilizing a plugin bag.
  *
  * @see \Drupal\Component\Plugin\PluginBag
+ *
+ * @ingroup plugin_api
  */
 interface EntityWithPluginBagsInterface extends EntityInterface {
 

core/lib/Drupal/Core/Executable/ExecutableInterface.php

@@ -9,6 +9,8 @@
 
 /**
  * An interface for executable plugins.
+ *
+ * @ingroup plugin_api
  */
 interface ExecutableInterface {
 

core/lib/Drupal/Core/Plugin/DefaultPluginManager.php

@@ -23,6 +23,8 @@
 
 /**
  * Base class for plugin managers.
+ *
+ * @ingroup plugin_api
  */
 class DefaultPluginManager extends PluginManagerBase implements PluginManagerInterface, CachedDiscoveryInterface {
 

core/lib/Drupal/Core/Plugin/PluginBase.php

@@ -13,6 +13,8 @@
 
 /**
  * Base class for plugins supporting metadata inspection and translation.
+ *
+ * @ingroup plugin_api
  */
 abstract class PluginBase extends ComponentPluginBase {
   use StringTranslationTrait;

core/lib/Drupal/Core/Plugin/PluginFormInterface.php

@@ -9,6 +9,8 @@
 
 /**
  * Provides an interface for a plugin that contains a form.
+ *
+ * @ingroup plugin_api
  */
 interface PluginFormInterface {
 

core/modules/search/search.module

@@ -551,12 +551,7 @@ function search_mark_for_reindex($type, $sid) {
  * data. Most of the system is handled by the Search module, so this must be
  * enabled for all of the search features to work.
  *
- * To be discovered, the plugins must implement
- * \Drupal\search\Plugin\SearchInterface and be annotated as
- * \Drupal\search\Annotation\SearchPlugin plugins. Defining a plugin will allow
- * administrators to set up one or more search pages using this plugin.
- *
- * There are three ways to interact with the search system:
+ * There are two ways to interact with the search system:
  * - Specifically for searching nodes, you can implement
  *   hook_node_update_index() and hook_node_search_result(). However, note that
  *   the search system already indexes all visible output of a node; i.e.,
@@ -569,12 +564,16 @@ function search_mark_for_reindex($type, $sid) {
  *   Each of these corresponds to a tab on the /search page, which can be
  *   used to perform searches. You will also need to implement the execute()
  *   method from the interface to perform the search. A base class is provided
- *   in \Drupal\search\Plugin\SearchPluginBase.
+ *   in \Drupal\search\Plugin\SearchPluginBase. For more information about
+ *   plugins, see the @link plugin_api Plugin API topic. @endlink
  *
  * If your module needs to provide a more complicated search form, then you
  * need to implement it yourself. In that case, you may wish to define it as a
  * local task (tab) under the /search page (e.g. /search/mymodule) so that users
  * can easily find it.
+ *
+ * @see plugin_api
+ * @see annotation
  */
 
 /**

core/modules/views/views.api.php

@@ -12,7 +12,8 @@
  *
  * Views plugins are objects that are used to build and render the view.
  * Plugins are registered by extending one of the Views base plugin classes
- * and defining settings in the plugin annotation.
+ * and defining settings in the plugin annotation. For more information about
+ * plugins, see the @link plugin_api Plugin API topic. @endlink
  *
  * Views has the following types of plugins:
  * - Access: Access plugins are responsible for controlling access to the
@@ -83,7 +84,6 @@
  *   \Drupal\views\Plugin\views\style\StylePluginBase.
  *
  * @todo Add an explanation for each type of handler.
- * @todo Document how to use annotations and what goes in them.
  * @todo Add @ingroup to all the base plugins for this group.
  * @todo Add a separate @ingroup for all plugins?
  * @todo Document specific options on the appropriate plugin base classes.
@@ -91,6 +91,8 @@
  *
  * @see \Drupal\views\Plugin\views\PluginBase
  * @see \Drupal\views\Plugin\views\HandlerBase
+ * @see plugin_api
+ * @see annotation
  */
 
 /**