--- /dev/null
+<?php
+
+namespace Drupal\media_test_source\Plugin\media\Source;
+
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\media\MediaInterface;
+use Drupal\media\MediaSourceBase;
+
+/**
+ * Provides test media source.
+ *
+ * @MediaSource(
+ * id = "test",
+ * label = @Translation("Test source"),
+ * description = @Translation("Test media source."),
+ * allowed_field_types = {"string"},
+ * )
+ */
+class Test extends MediaSourceBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getMetadataAttributes() {
+ // The metadata attributes are kept in state storage. This allows tests to
+ // change the metadata attributes and makes it easier to test different
+ // variations.
+ $attributes = \Drupal::state()->get('media_source_test_attributes', [
+ 'attribute_1' => ['label' => $this->t('Attribute 1'), 'value' => 'Value 1'],
+ 'attribute_2' => ['label' => $this->t('Attribute 2'), 'value' => 'Value 1'],
+ ]);
+ return array_map(function ($item) {
+ return $item['label'];
+ }, $attributes);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getMetadata(MediaInterface $media, $attribute_name) {
+ $attributes = \Drupal::state()->get('media_source_test_attributes', [
+ 'attribute_1' => ['label' => $this->t('Attribute 1'), 'value' => 'Value 1'],
+ 'attribute_2' => ['label' => $this->t('Attribute 2'), 'value' => 'Value 1'],
+ ]);
+
+ if (in_array($attribute_name, array_keys($attributes))) {
+ return $attributes[$attribute_name]['value'];
+ }
+
+ return parent::getMetadata($media, $attribute_name);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getPluginDefinition() {
+ return NestedArray::mergeDeep(
+ parent::getPluginDefinition(),
+ \Drupal::state()->get('media_source_test_definition', [])
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function defaultConfiguration() {
+ return parent::defaultConfiguration() + [
+ 'test_config_value' => 'This is default value.',
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+ $form = parent::buildConfigurationForm($form, $form_state);
+
+ $form['test_config_value'] = [
+ '#type' => 'textfield',
+ '#title' => $this->t('Test config value'),
+ '#default_value' => $this->configuration['test_config_value'],
+ ];
+
+ return $form;
+ }
+
+}