class OgContext in Organic groups 8

Provides the group that best matches the current context.

There might be several groups that are relevant in the current context, and this class tries to determine which is the best possible candidate.

For example, if we are on a page that displays a group content entity that belongs to two groups, then both groups are relevant in the current context. We might then decide which group is the better candidate by looking at a URL query argument or inspecting the user's browsing history to see if they are coming from a group page.

This discovery of groups is handled by OgGroupResolver plugins. Each plugin is responsible for discovering groups in a specific domain (e.g. find all groups belonging to the current route). The plugins that will be used for the discovery are configurable; they are listed under the 'group_resolvers' key in the 'og.settings' config. The plugins are ordered by priority, meaning that if two groups are relevant to the current context, then the plugin with the highest priority will decide which group is going to 'win'.

Developers can customize the group context result by providing their own plugins and by activating, disabling or reordering the default ones.

Hierarchy

class \Drupal\og\ContextProvider\OgContext implements ContextProviderInterface, OgContextInterface uses StringTranslationTrait

Expanded class hierarchy of OgContext

1 file declares its use of OgContext

OgContextTest.php in tests/src/Unit/OgContextTest.php

1 string reference to 'OgContext'

og.services.yml in ./og.services.yml: og.services.yml

1 service uses OgContext

og.context in ./og.services.yml: Drupal\og\ContextProvider\OgContext

File

src/ContextProvider/OgContext.php, line 41

Namespace

Drupal\og\ContextProvider

View source

class OgContext implements OgContextInterface, ContextProviderInterface {
  use StringTranslationTrait;

  /**
   * The OgGroupResolver plugin manager.
   *
   * @var \Drupal\Component\Plugin\PluginManagerInterface
   */
  protected $pluginManager;

  /**
   * The config factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * Constructs a new OgContext.
   *
   * @param \Drupal\Component\Plugin\PluginManagerInterface $plugin_manager
   *   The OgGroupResolver plugin manager.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   */
  public function __construct(PluginManagerInterface $plugin_manager, ConfigFactoryInterface $config_factory) {
    $this->pluginManager = $plugin_manager;
    $this->configFactory = $config_factory;
  }

  /**
   * {@inheritdoc}
   */
  public function getRuntimeContexts(array $unqualified_context_ids) {

    // Don't bother to resolve the group context if it is not requested.
    if (!in_array('og', $unqualified_context_ids)) {
      return [];
    }
    return [
      'og' => $this
        ->getOgContext(),
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function getAvailableContexts() {
    $context = new Context(new ContextDefinition('entity', $this
      ->t('Active group')));
    return [
      'og' => $context,
    ];
  }

  /**
   * Returns the context object containing the relevant group.
   *
   * @return \Drupal\Core\Plugin\Context\Context
   *   A context object containing the group which is relevant in the current
   *   context as a value. If there is no relevant group in the current context
   *   then the value will be empty.
   */
  protected function getOgContext() {
    $context_definition = new ContextDefinition('entity', $this
      ->t('Active group'), FALSE);
    $candidate = $this
      ->getBestCandidate();
    $group = !empty($candidate['entity']) ? $candidate['entity'] : NULL;
    $context = new Context($context_definition, $group);
    $cacheability = new CacheableMetadata();
    if (!empty($candidate['cache_contexts'])) {
      $cacheability
        ->setCacheContexts($candidate['cache_contexts']);
    }
    $context
      ->addCacheableDependency($cacheability);
    return $context;
  }

  /**
   * Returns information about the group which best matches the current context.
   *
   * @return array|null
   *   An associative array with information about the chosen candidate. It has
   *   the following keys:
   *   - entity: the group entity.
   *   - votes: an array of votes that have been cast for this entity.
   *   - cache_contexts: an array of cache contexts that were used to discover
   *     this group.
   *   If no group was found in the current context, NULL is returned.
   *
   * @see \Drupal\og\OgGroupResolverInterface
   */
  protected function getBestCandidate() {
    $collection = new OgResolvedGroupCollection();

    // Retrieve the list of group resolvers. These are stored in config, and are
    // ordered by priority.
    $group_resolvers = $this->configFactory
      ->get('og.settings')
      ->get('group_resolvers');
    $priority = 0;
    foreach ($group_resolvers as $plugin_id) {

      /** @var \Drupal\og\OgGroupResolverInterface $plugin */
      if ($plugin = $this->pluginManager
        ->createInstance($plugin_id)) {

        // Set the default vote weight according to the plugin's priority.
        $collection
          ->setVoteWeight($priority);

        // Let the plugin do its magic.
        $plugin
          ->resolve($collection);

        // If the plugin is certain that the candidate belongs to the current
        // context, it can declare the search to be over.
        if ($plugin
          ->isPropagationStopped()) {
          break;
        }

        // The next plugin we try will have a lower priority.
        $priority--;
      }
    }

    // Sort the resolved groups and retrieve the first result, this will be the
    // best candidate.
    $collection
      ->sort();
    $group_info = $collection
      ->getGroupInfo();
    if (!empty($group_info)) {
      return reset($group_info);
    }
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function getGroup() {
    $contexts = $this
      ->getRuntimeContexts([
      'og',
    ]);
    if (!empty($contexts['og']) && ($group = $contexts['og']
      ->getContextValue())) {
      if ($group instanceof ContentEntityInterface) {
        return $group;
      }
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
OgContext::$configFactory	protected	property	The config factory.
OgContext::$pluginManager	protected	property	The OgGroupResolver plugin manager.
OgContext::getAvailableContexts	public	function	Gets all available contexts for the purposes of configuration. Overrides ContextProviderInterface::getAvailableContexts
OgContext::getBestCandidate	protected	function	Returns information about the group which best matches the current context.
OgContext::getGroup	public	function	Returns the group which is relevant in the current context, if any. Overrides OgContextInterface::getGroup
OgContext::getOgContext	protected	function	Returns the context object containing the relevant group.
OgContext::getRuntimeContexts	public	function	Gets runtime context values for the given context IDs. Overrides ContextProviderInterface::getRuntimeContexts
OgContext::__construct	public	function	Constructs a new OgContext.
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.

You are here

class OgContext in Organic groups 8

Hierarchy

File

Namespace

Members

API Navigation