abstract class LazyPluginCollection in Drupal 8

Defines an object which stores multiple plugin instances to lazy load them.

Hierarchy

• class \Drupal\Component\Plugin\LazyPluginCollection implements \Drupal\Component\Plugin\IteratorAggregate, \Drupal\Component\Plugin\Countable

Related topics

Plugin API

Using the Plugin API

3 files declare their use of LazyPluginCollection

DefaultLazyPluginCollection.php in core/lib/Drupal/Core/Plugin/DefaultLazyPluginCollection.php

DefaultSingleLazyPluginCollection.php in core/lib/Drupal/Core/Plugin/DefaultSingleLazyPluginCollection.php

TestLazyPluginCollection.php in core/modules/system/tests/modules/plugin_test/src/Plugin/TestLazyPluginCollection.php

File

core/lib/Drupal/Component/Plugin/LazyPluginCollection.php, line 10

Namespace

Drupal\Component\Plugin

abstract class LazyPluginCollection implements \IteratorAggregate, \Countable {

  /**
   * Stores all instantiated plugins.
   *
   * @var array
   */
  protected $pluginInstances = [];

  /**
   * Stores the IDs of all potential plugin instances.
   *
   * @var array
   */
  protected $instanceIds = [];

  /**
   * Initializes and stores a plugin.
   *
   * @param string $instance_id
   *   The ID of the plugin instance to initialize.
   */
  protected abstract function initializePlugin($instance_id);

  /**
   * Gets the current configuration of all plugins in this collection.
   *
   * @return array
   *   An array of up-to-date plugin configuration.
   */
  public abstract function getConfiguration();

  /**
   * Sets the configuration for all plugins in this collection.
   *
   * @param array $configuration
   *   An array of up-to-date plugin configuration.
   *
   * @return $this
   */
  public abstract function setConfiguration($configuration);

  /**
   * Clears all instantiated plugins.
   */
  public function clear() {
    $this->pluginInstances = [];
  }

  /**
   * Determines if a plugin instance exists.
   *
   * @param string $instance_id
   *   The ID of the plugin instance to check.
   *
   * @return bool
   *   TRUE if the plugin instance exists, FALSE otherwise.
   */
  public function has($instance_id) {
    return isset($this->pluginInstances[$instance_id]) || isset($this->instanceIds[$instance_id]);
  }

  /**
   * Gets a plugin instance, initializing it if necessary.
   *
   * @param string $instance_id
   *   The ID of the plugin instance being retrieved.
   */
  public function &get($instance_id) {
    if (!isset($this->pluginInstances[$instance_id])) {
      $this
        ->initializePlugin($instance_id);
    }
    return $this->pluginInstances[$instance_id];
  }

  /**
   * Stores an initialized plugin.
   *
   * @param string $instance_id
   *   The ID of the plugin instance being stored.
   * @param mixed $value
   *   An instantiated plugin.
   */
  public function set($instance_id, $value) {
    $this->pluginInstances[$instance_id] = $value;
    $this
      ->addInstanceId($instance_id);
  }

  /**
   * Removes an initialized plugin.
   *
   * The plugin can still be used; it will be reinitialized.
   *
   * @param string $instance_id
   *   The ID of the plugin instance to remove.
   */
  public function remove($instance_id) {
    unset($this->pluginInstances[$instance_id]);
  }

  /**
   * Adds an instance ID to the available instance IDs.
   *
   * @param string $id
   *   The ID of the plugin instance to add.
   * @param array|null $configuration
   *   (optional) The configuration used by this instance. Defaults to NULL.
   */
  public function addInstanceId($id, $configuration = NULL) {
    if (!isset($this->instanceIds[$id])) {
      $this->instanceIds[$id] = $id;
    }
  }

  /**
   * Gets all instance IDs.
   *
   * @return array
   *   An array of all available instance IDs.
   */
  public function getInstanceIds() {
    return $this->instanceIds;
  }

  /**
   * Removes an instance ID.
   *
   * @param string $instance_id
   *   The ID of the plugin instance to remove.
   */
  public function removeInstanceId($instance_id) {
    unset($this->instanceIds[$instance_id]);
    $this
      ->remove($instance_id);
  }
  public function getIterator() {
    $instances = [];
    foreach ($this
      ->getInstanceIds() as $instance_id) {
      $instances[$instance_id] = $this
        ->get($instance_id);
    }
    return new \ArrayIterator($instances);
  }

  /**
   * {@inheritdoc}
   */
  public function count() {
    return count($this->instanceIds);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
LazyPluginCollection::$instanceIds	protected	property	Stores the IDs of all potential plugin instances.
LazyPluginCollection::$pluginInstances	protected	property	Stores all instantiated plugins.
LazyPluginCollection::addInstanceId	public	function	Adds an instance ID to the available instance IDs.	1
LazyPluginCollection::clear	public	function	Clears all instantiated plugins.
LazyPluginCollection::count	public	function
LazyPluginCollection::get	public	function	Gets a plugin instance, initializing it if necessary.	4
LazyPluginCollection::getConfiguration	abstract public	function	Gets the current configuration of all plugins in this collection.	2
LazyPluginCollection::getInstanceIds	public	function	Gets all instance IDs.
LazyPluginCollection::getIterator	public	function
LazyPluginCollection::has	public	function	Determines if a plugin instance exists.
LazyPluginCollection::initializePlugin	abstract protected	function	Initializes and stores a plugin.	2
LazyPluginCollection::remove	public	function	Removes an initialized plugin.
LazyPluginCollection::removeInstanceId	public	function	Removes an instance ID.
LazyPluginCollection::set	public	function	Stores an initialized plugin.
LazyPluginCollection::setConfiguration	abstract public	function	Sets the configuration for all plugins in this collection.	2