--- /dev/null
+<?php
+
+namespace Drupal\migrate\Plugin;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\migrate\Plugin\Discovery\AnnotatedClassDiscoveryAutomatedProviders;
+use Drupal\Core\Plugin\Discovery\ContainerDerivativeDiscoveryDecorator;
+use Drupal\migrate\Plugin\Discovery\ProviderFilterDecorator;
+
+/**
+ * Plugin manager for migrate source plugins.
+ *
+ * @see \Drupal\migrate\Plugin\MigrateSourceInterface
+ * @see \Drupal\migrate\Plugin\source\SourcePluginBase
+ * @see \Drupal\migrate\Annotation\MigrateSource
+ * @see plugin_api
+ *
+ * @ingroup migration
+ */
+class MigrateSourcePluginManager extends MigratePluginManager {
+
+ /**
+ * MigrateSourcePluginManager constructor.
+ *
+ * @param string $type
+ * The type of the plugin: row, source, process, destination, entity_field,
+ * id_map.
+ * @param \Traversable $namespaces
+ * An object that implements \Traversable which contains the root paths
+ * keyed by the corresponding namespace to look for plugin implementations.
+ * @param \Drupal\Core\Cache\CacheBackendInterface $cache_backend
+ * Cache backend instance to use.
+ * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+ * The module handler to invoke the alter hook with.
+ */
+ public function __construct($type, \Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
+ parent::__construct($type, $namespaces, $cache_backend, $module_handler, 'Drupal\migrate\Annotation\MigrateSource');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function getDiscovery() {
+ if (!$this->discovery) {
+ $discovery = new AnnotatedClassDiscoveryAutomatedProviders($this->subdir, $this->namespaces, $this->pluginDefinitionAnnotationName, $this->additionalAnnotationNamespaces);
+ $this->discovery = new ContainerDerivativeDiscoveryDecorator($discovery);
+ }
+ return $this->discovery;
+ }
+
+ /**
+ * Finds plugin definitions.
+ *
+ * @return array
+ * List of definitions to store in cache.
+ *
+ * @todo This is a temporary solution to the fact that migration source
+ * plugins have more than one provider. This functionality will be moved to
+ * core in https://www.drupal.org/node/2786355.
+ */
+ protected function findDefinitions() {
+ $definitions = $this->getDiscovery()->getDefinitions();
+ foreach ($definitions as $plugin_id => &$definition) {
+ $this->processDefinition($definition, $plugin_id);
+ }
+ $this->alterDefinitions($definitions);
+ return ProviderFilterDecorator::filterDefinitions($definitions, function ($provider) {
+ return $this->providerExists($provider);
+ });
+ }
+
+}