Implementing Drupal 8 plugin support and making sitemap pluggable by other...

Implementing Drupal 8 plugin support and making sitemap pluggable by other modules providing sitemap links.

simplesitemap.module

@@ -19,7 +19,12 @@ function simplesitemap_form_alter(&$form, $form_state, $form_id) {
     return;
 
   $entity_type_id = $form_entity->getEntityTypeId();
-  if (!Simplesitemap::get_plugin_path($entity_type_id))
+
+  //todo: wrap into helper function
+  // Return if a sitemap plugin of this entity type does not exist.
+  $manager = \Drupal::service('plugin.manager.simplesitemap');
+  $plugins = $manager->getDefinitions();
+  if (!isset($plugins[$entity_type_id]))
     return;
 
   $bundle_name = $form_entity->Id();

simplesitemap.services.yml

+services:
+  plugin.manager.simplesitemap:
+    class: Drupal\simplesitemap\SimplesitemapManager
+    parent: default_plugin_manager

src/Annotation/LinkGenerator.php

+<?php
+/**
+ * @file
+ * Contains \Drupal\simplesitemap\Annotation\LinkGenerator.
+ */
+
+namespace Drupal\simplesitemap\Annotation;
+
+use Drupal\Component\Annotation\Plugin;
+
+/**
+ * Defines a LinkGenerator item annotation object.
+ *
+ * @see \Drupal\simplesitemap\Plugin\SimplesitemapManager
+ * @see plugin_api
+ *
+ * @Annotation
+ */
+class LinkGenerator extends Plugin {
+
+  /**
+   * The plugin ID.
+   *
+   * @var string
+   */
+  public $id;
+}

src/LinkGenerators/CustomLinkGenerator.php → src/CustomLinkGenerator.php

@@ -6,7 +6,7 @@
  * Generates custom sitemap links provided by the user.
  */
 
-namespace Drupal\simplesitemap\LinkGenerators;
+namespace Drupal\simplesitemap;
 
 use Drupal\Core\Url;
 

src/LinkGenerators/EntityLinkGenerator.php → src/LinkGeneratorBase.php

 <?php
 /**
  * @file
- * Contains \Drupal\simplesitemap\LinkGenerators\EntityLinkGenerator.
- *
- * Abstract class to be extended for plugin creation.
- * See \Drupal\simplesitemap\LinkGenerators\CustomLinkGenerator\node for more
- * documentation.
+ * Contains \Drupal\simplesitemap\LinkGeneratorBase.
  */
 
-namespace Drupal\simplesitemap\LinkGenerators;
+namespace Drupal\simplesitemap;
 
-/**
- * EntityLinkGenerator class.
- * @abstract
- */
-abstract class EntityLinkGenerator {
+use Drupal\Component\Plugin\PluginBase;
+
+abstract class LinkGeneratorBase extends PluginBase implements LinkGeneratorInterface {
 
   private $entity_links = array();
 
+  /**
+   * {@inheritdoc}
+   */
   public function get_entity_links($entity_type, $bundles, $languages) {
     $i = 0;
     foreach($bundles as $bundle => $bundle_settings) {

src/LinkGeneratorInterface.php

+<?php
+
+/**
+ * @file
+ * Provides Drupal\simplesitemap\LinkGenerator.
+ */
+
+namespace Drupal\simplesitemap;
+
+use Drupal\Component\Plugin\PluginInspectionInterface;
+
+/**
+ * Defines an interface for simplesitemap plugins.
+ */
+
+interface LinkGeneratorInterface extends PluginInspectionInterface {
+
+  /**
+   *
+   *
+   * @return array
+   */
+  public function get_entity_links($entity_type, $bundles, $languages);
+}

src/LinkGenerators/EntityTypeLinkGenerators/menu.php → src/Plugin/LinkGenerator/Menu.php

 <?php
 /**
  * @file
- * Contains \Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators\menu.
+ * Contains \Drupal\simplesitemap\LinkGenerator\Menu.
  *
  * Plugin for menu entity link generation.
- * See \Drupal\simplesitemap\LinkGenerators\CustomLinkGenerator\node_type for more
- * documentation.
  */
 
-namespace Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators;
+namespace Drupal\simplesitemap\Plugin\LinkGenerator;
 
-use Drupal\simplesitemap\LinkGenerators\EntityLinkGenerator;
+use Drupal\simplesitemap\Annotation\LinkGenerator;
+use Drupal\simplesitemap\LinkGeneratorBase;
 use Drupal\Core\Url;
 
 /**
- * menu class.
+ * Menu class.
+ *
+ * @LinkGenerator(
+ *   id = "menu"
+ * )
  */
-class menu extends EntityLinkGenerator {
+class Menu extends LinkGeneratorBase {
 
   /**
    * {@inheritdoc}

src/LinkGenerators/EntityTypeLinkGenerators/node_type.php → src/Plugin/LinkGenerator/NodeType.php

 <?php
 /**
  * @file
- * Contains \Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators\node_type.
+ * Contains \Drupal\simplesitemap\Plugin\LinkGenerator\NodeType.
  *
- * Plugin for node entity link generation.
- *
- * This can be used as a template to create new plugins for other configuration
- * entity types. To create a plugin simply create a new class file in the
- * EntityTypeLinkGenerators folder. Name this file after the configuration
- * entity type id (eg. 'node_type' or 'taxonomy_vocabulary'.)
- * This class needs to extend the EntityLinkGenerator class and include
- * the get_entity_bundle_links() method. - as shown here. This method has to
- * return an array of pure urls to the entities of the configuration entity type
- * in question.
+ * Plugin for taxonomy term entity link generation.
  */
 
-namespace Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators;
+namespace Drupal\simplesitemap\Plugin\LinkGenerator;
 
-use Drupal\simplesitemap\LinkGenerators\EntityLinkGenerator;
+use Drupal\simplesitemap\Annotation\LinkGenerator;
+use Drupal\simplesitemap\LinkGeneratorBase;
 use Drupal\Core\Url;
 
 /**
- * node_type class.
+ * NodeType class.
+ *
+ * @LinkGenerator(
+ *   id = "node_type"
+ * )
  */
-class node_type extends EntityLinkGenerator {
+class NodeType extends LinkGeneratorBase {
 
   /**
    * {@inheritdoc}

src/LinkGenerators/EntityTypeLinkGenerators/taxonomy_vocabulary.php → src/Plugin/LinkGenerator/TaxonomyVocabulary.php

 <?php
 /**
  * @file
- * Contains \Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators\taxonomy_vocabulary.
+ * Contains \Drupal\simplesitemap\LinkGenerator\TaxonomyVocabulary.
  *
  * Plugin for taxonomy term entity link generation.
- * See \Drupal\simplesitemap\LinkGenerators\CustomLinkGenerator\node_type for more
- * documentation.
  */
 
-namespace Drupal\simplesitemap\LinkGenerators\EntityTypeLinkGenerators;
+namespace Drupal\simplesitemap\Plugin\LinkGenerator;
 
-use Drupal\simplesitemap\LinkGenerators\EntityLinkGenerator;
+use Drupal\simplesitemap\Annotation\LinkGenerator;
+use Drupal\simplesitemap\LinkGeneratorBase;
 use Drupal\Core\Url;
 
 /**
- * taxonomy_vocabulary class.
+ * TaxonomyVocabulary class.
+ *
+ * @LinkGenerator(
+ *   id = "taxonomy_vocabulary"
+ * )
  */
-class taxonomy_vocabulary extends EntityLinkGenerator {
+class TaxonomyVocabulary extends LinkGeneratorBase {
 
   /**
    * {@inheritdoc}

src/Simplesitemap.php

@@ -13,8 +13,6 @@ namespace Drupal\simplesitemap;
  */
 class Simplesitemap {
 
-  const SITEMAP_PLUGIN_PATH = 'src/LinkGenerators/EntityTypeLinkGenerators';
-
   private $config;
   private $sitemap;
 
@@ -37,21 +35,6 @@ class Simplesitemap {
     return FALSE;
   }
 
-  /**
-   * Returns path of a sitemap plugin.
-   *
-   * @param string $entity_type_name
-   * @return string $class_path or FALSE if non-existent.
-   */
-  public static function get_plugin_path($entity_type_name) {
-    $class_path = drupal_get_path('module', 'simplesitemap')
-      . '/' . self::SITEMAP_PLUGIN_PATH . '/' . $entity_type_name . '.php';
-    if (file_exists($class_path)) {
-      return $class_path;
-    }
-    return FALSE;
-  }
-
   private function initialize() {
     $this->get_config_from_db();
     $this->get_sitemap_from_db();

src/SimplesitemapManager.php

+<?php
+/**
+ * @file
+ * Contains SimplesitemapManager.
+ */
+
+namespace Drupal\simplesitemap;
+
+use Drupal\Core\Plugin\DefaultPluginManager;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+
+/**
+ * Simplesitemap plugin manager.
+ */
+class SimplesitemapManager extends DefaultPluginManager {
+
+  /**
+   * Constructs an SimplesitemapManager object.
+   *
+   * @param \Traversable $namespaces
+   *   An object that implements \Traversable which contains the root paths
+   *   keyed by the corresponding namespace to look for plugin implementations,
+   * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
+   *   Cache backend instance to use.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler to invoke the alter hook with.
+   */
+  public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
+    parent::__construct('Plugin/LinkGenerator', $namespaces, $module_handler, 'Drupal\simplesitemap\LinkGeneratorInterface', 'Drupal\simplesitemap\Annotation\LinkGenerator');
+
+    $this->alterInfo('simplesitemap_link_generators_info');
+    $this->setCacheBackend($cache_backend, 'simplesitemap_flavors');
+  }
+}

src/SitemapGenerator.php

@@ -8,7 +8,6 @@
 
 namespace Drupal\simplesitemap;
 
-use Drupal\simplesitemap\LinkGenerators\CustomLinkGenerator;
 use \XMLWriter;
 
 /**
@@ -181,13 +180,16 @@ class SitemapGenerator {
    * Gets entity type links.
    */
   private function generate_entity_links() {
-    foreach($this->entity_types as $entity_type => $bundles) {
-      $class_path = Simplesitemap::get_plugin_path($entity_type);
-      if ($class_path !== FALSE) {
-        require_once $class_path;
-        $class_name = "Drupal\\simplesitemap\\LinkGenerators\\EntityTypeLinkGenerators\\$entity_type";
-        $link_generator = new $class_name();
-        $links = $link_generator->get_entity_links($entity_type, $bundles, $this->languages);
+
+    $manager = \Drupal::service('plugin.manager.simplesitemap');
+    $plugins = $manager->getDefinitions();
+
+    foreach ($plugins as $link_generator_plugin) {
+      if (isset($this->entity_types[$link_generator_plugin['id']])) {
+        $instance = $manager->createInstance($link_generator_plugin['id']);
+        $links = $instance->get_entity_links($link_generator_plugin['id'],
+          $this->entity_types[$link_generator_plugin['id']],
+          $this->languages);
         $this->links = array_merge($this->links, $links);
       }
     }