--- /dev/null
+<?php
+
+namespace Drupal\video_embed_field;
+
+use Drupal\Component\Plugin\Mapper\MapperInterface;
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Plugin\DefaultPluginManager;
+
+/**
+ * Gathers the provider plugins.
+ */
+class ProviderManager extends DefaultPluginManager implements ProviderManagerInterface, MapperInterface {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct(\Traversable $namespaces, CacheBackendInterface $cache_backend, ModuleHandlerInterface $module_handler) {
+ parent::__construct('Plugin/video_embed_field/Provider', $namespaces, $module_handler, 'Drupal\video_embed_field\ProviderPluginInterface', 'Drupal\video_embed_field\Annotation\VideoEmbedProvider');
+ $this->alterInfo('video_embed_field_provider_info');
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getProvidersOptionList() {
+ $options = [];
+ foreach ($this->getDefinitions() as $definition) {
+ $options[$definition['id']] = $definition['title'];
+ }
+ return $options;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function loadDefinitionsFromOptionList($options) {
+ $definitions = [];
+ // When no options are selected, all plugins are applicable.
+ if (count(array_keys($options, '0')) == count($options) || empty($options)) {
+ return $this->getDefinitions();
+ }
+ else {
+ foreach ($options as $provider_id => $enabled) {
+ if ($enabled) {
+ $definitions[$provider_id] = $this->getDefinition($provider_id);
+ }
+ }
+ }
+ return $definitions;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function filterApplicableDefinitions(array $definitions, $user_input) {
+ foreach ($definitions as $definition) {
+ $is_applicable = $definition['class']::isApplicable($user_input);
+ if ($is_applicable) {
+ return $definition;
+ }
+ }
+ return FALSE;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function loadProviderFromInput($input) {
+ $definition = $this->loadDefinitionFromInput($input);
+ return $definition ? $this->createInstance($definition['id'], ['input' => $input]) : FALSE;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function loadDefinitionFromInput($input) {
+ return $this->filterApplicableDefinitions($this->getDefinitions(), $input);
+ }
+
+}