Default argument for current user memberships.

src/Plugin/views/argument_default/Membership.php

@@ -0,0 +1,172 @@
+<?php
+
+namespace Drupal\og\Plugin\views\argument_default;
+
+use Drupal\Core\Cache\Cache;
+use Drupal\Core\Cache\CacheableDependencyInterface;
+use Drupal\Core\Entity\ContentEntityInterface;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Plugin\Context\ContextProviderInterface;
+use Drupal\views\Plugin\views\argument_default\ArgumentDefaultPluginBase;
+use Drupal\og\MembershipManagerInterface;
+use Drupal\Core\Session\AccountInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Default argument plugin to provide the group memberships from the current context.
+ *
+ * @ViewsArgumentDefault(
+ *   id = "og_group_membership",
+ *   title = @Translation("Group memberships from current user")
+ * )
+ */
+class Membership extends ArgumentDefaultPluginBase implements CacheableDependencyInterface {
+
+  /**
+   * The OG context provider.
+   *
+   * @var \Drupal\Core\Plugin\Context\ContextProviderInterface
+   */
+  protected $ogContext;
+
+  /**
+   * The OG membership manager.
+   *
+   * @var \Drupal\og\MembershipManagerInterface
+   */
+  protected $ogMembership;
+
+  /**
+   * The user to be evaluated.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $ogUser;
+
+  /**
+   * Constructs a new Membership instance.
+   *
+   * @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\Plugin\Context\ContextProviderInterface $og_context
+   *   The OG context provider.
+   * @param \Drupal\og\MembershipManagerInterface $og_membership
+   *   The OG membership manager.
+   * @param \Drupal\Core\Session\AccountInterface $og_user
+   *   The user to be evaluated.
+   */
+  public function __construct(array $configuration, $plugin_id, $plugin_definition, ContextProviderInterface $og_context, MembershipManagerInterface $og_membership, AccountInterface $og_user) {
+    parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+    $this->ogContext = $og_context;
+    $this->ogMembership = $og_membership;
+    $this->ogUser = $og_user;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+    return new static(
+      $configuration,
+      $plugin_id,
+      $plugin_definition,
+      $container->get('og.context'),
+      $container->get('og.membership_manager'),
+      $container->get('current_user')->getAccount()
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function defineOptions() {
+    $options = parent::defineOptions();
+    $options['og_group_membership'] = ['default' => ''];
+
+    return $options;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+    $form['og_group_membership'] = [];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getArgument() {
+    // Currently restricted to node entities.
+    return implode(',', $this->getCurrentUserGroupIds('node'));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheMaxAge() {
+    return Cache::PERMANENT;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheContexts() {
+    // This cache context is the best thing we have right now.
+    // og_role takes in consideration the user memberships and 
+    // the roles held in the corresponding groups, and while it 
+    // is one level too granular, i.e. the context will be more 
+    // fragmented than strictly needed, it works.
+    return ['og_role'];
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCacheTags() {
+    $group = $this->getGroup();
+    if ($group instanceof ContentEntityInterface) {
+      $tag = $group->getEntityTypeId() . ':' . $group->id();
+      return Cache::buildTags('og-group-content', [$tag]);
+    }
+    return [];
+  }
+
+  /**
+   * Returns groups that current user is a member of.
+   *
+   * @param string $entity_type
+   *   The entity type, defaults to 'node'.
+   *
+   * @return array
+   *   An array of groups, or an empty array if no group is found.
+   */
+  protected function getCurrentUserGroupIds($entity_type = 'node') {
+    $groups = $this->ogMembership->getUserGroupIds($this->ogUser);
+    if (!empty($groups) && isset($groups[$entity_type])) {
+      return $groups[$entity_type];
+    }
+    return [];
+  }
+
+  /**
+   * Returns the group from the runtime context.
+   *
+   * @return \Drupal\Core\Entity\ContentEntityInterface|null
+   *   The group from context if found.
+   */
+  protected function getGroup() {
+    $contexts = $this->ogContext->getRuntimeContexts(['og']);
+    if (!empty($contexts['og']) && $group = $contexts['og']->getContextValue()) {
+      if ($group instanceof ContentEntityInterface) {
+        return $group;
+      }
+    }
+  }
+
+}