FilteredPluginManagerTrait.php

<?php

namespace Drupal\Core\Plugin;

use Drupal\Core\Extension\ModuleHandlerInterface;
use Drupal\Core\Plugin\Context\ContextAwarePluginManagerTrait;
use Drupal\Core\Theme\ThemeManagerInterface;

/**
 * Provides a trait for plugin managers that allow filtering plugin definitions.
 */
trait FilteredPluginManagerTrait {
    use ContextAwarePluginManagerTrait;
    
    /**
     * Implements \Drupal\Core\Plugin\FilteredPluginManagerInterface::getFilteredDefinitions().
     */
    public function getFilteredDefinitions($consumer, $contexts = NULL, array $extra = []) {
        if (!is_null($contexts)) {
            $definitions = $this->getDefinitionsForContexts($contexts);
        }
        else {
            $definitions = $this->getDefinitions();
        }
        $type = $this->getType();
        $hooks = [];
        $hooks[] = "plugin_filter_{$type}";
        $hooks[] = "plugin_filter_{$type}__{$consumer}";
        $this->moduleHandler()
            ->alter($hooks, $definitions, $extra, $consumer);
        $this->themeManager()
            ->alter($hooks, $definitions, $extra, $consumer);
        return $definitions;
    }
    
    /**
     * A string identifying the plugin type.
     *
     * This string should be unique and generally will correspond to the string
     * used by the discovery, e.g. the annotation class or the YAML file name.
     *
     * @return string
     *   A string identifying the plugin type.
     */
    protected abstract function getType();
    
    /**
     * Wraps the module handler.
     *
     * @return \Drupal\Core\Extension\ModuleHandlerInterface
     *   The module handler.
     */
    protected function moduleHandler() {
        if (property_exists($this, 'moduleHandler') && $this->moduleHandler instanceof ModuleHandlerInterface) {
            return $this->moduleHandler;
        }
        return \Drupal::service('module_handler');
    }
    
    /**
     * Wraps the theme manager.
     *
     * @return \Drupal\Core\Theme\ThemeManagerInterface
     *   The theme manager.
     */
    protected function themeManager() {
        if (property_exists($this, 'themeManager') && $this->themeManager instanceof ThemeManagerInterface) {
            return $this->themeManager;
        }
        return \Drupal::service('theme.manager');
    }

}