PluginDependencyTrait.php

<?php

namespace Drupal\Core\Plugin;

use Drupal\Component\Plugin\Definition\PluginDefinitionInterface;
use Drupal\Component\Plugin\DependentPluginInterface;
use Drupal\Component\Plugin\PluginInspectionInterface;
use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Entity\DependencyTrait;
use Drupal\Core\Plugin\Definition\DependentPluginDefinitionInterface;

/**
 * Provides a trait for calculating the dependencies of a plugin.
 */
trait PluginDependencyTrait {
    use DependencyTrait;
    
    /**
     * Calculates and returns dependencies of a specific plugin instance.
     *
     * Dependencies are added for the module that provides the plugin, as well
     * as any dependencies declared by the instance's calculateDependencies()
     * method, if it implements
     * \Drupal\Component\Plugin\DependentPluginInterface.
     *
     * @param \Drupal\Component\Plugin\PluginInspectionInterface $instance
     *   The plugin instance.
     *
     * @return array
     *   An array of dependencies keyed by the type of dependency.
     */
    protected function getPluginDependencies(PluginInspectionInterface $instance) {
        $dependencies = [];
        $definition = $instance->getPluginDefinition();
        $provider = NULL;
        $config_dependencies = [];
        if ($definition instanceof PluginDefinitionInterface) {
            $provider = $definition->getProvider();
            if ($definition instanceof DependentPluginDefinitionInterface) {
                $config_dependencies = $definition->getConfigDependencies();
            }
        }
        elseif (is_array($definition)) {
            $provider = $definition['provider'];
            if (isset($definition['config_dependencies'])) {
                $config_dependencies = $definition['config_dependencies'];
            }
        }
        // Add the provider as a dependency, taking into account if it's a module or
        // a theme.
        if ($provider) {
            if ($provider === 'core' || $this->moduleHandler()
                ->moduleExists($provider)) {
                $dependencies['module'][] = $provider;
            }
            elseif ($this->themeHandler()
                ->themeExists($provider)) {
                $dependencies['theme'][] = $provider;
            }
        }
        // Add the config dependencies.
        if ($config_dependencies) {
            $dependencies = NestedArray::mergeDeep($dependencies, $config_dependencies);
        }
        // If a plugin is dependent, calculate its dependencies.
        if ($instance instanceof DependentPluginInterface && ($plugin_dependencies = $instance->calculateDependencies())) {
            $dependencies = NestedArray::mergeDeep($dependencies, $plugin_dependencies);
        }
        return $dependencies;
    }
    
    /**
     * Calculates and adds dependencies of a specific plugin instance.
     *
     * Dependencies are added for the module that provides the plugin, as well
     * as any dependencies declared by the instance's calculateDependencies()
     * method, if it implements
     * \Drupal\Component\Plugin\DependentPluginInterface.
     *
     * @param \Drupal\Component\Plugin\PluginInspectionInterface $instance
     *   The plugin instance.
     */
    protected function calculatePluginDependencies(PluginInspectionInterface $instance) {
        $this->addDependencies($this->getPluginDependencies($instance));
    }
    
    /**
     * Wraps the module handler.
     *
     * @return \Drupal\Core\Extension\ModuleHandlerInterface
     *   The module handler.
     */
    protected function moduleHandler() {
        return \Drupal::moduleHandler();
    }
    
    /**
     * Wraps the theme handler.
     *
     * @return \Drupal\Core\Extension\ThemeHandlerInterface
     *   The theme handler.
     */
    protected function themeHandler() {
        return \Drupal::service('theme_handler');
    }

}