--- /dev/null
+/**
+ * Implements hook_field_formatter_third_party_settings_form().
+ */
+function {{ machine_name }}_field_formatter_third_party_settings_form(\Drupal\Core\Field\FormatterInterface $plugin, \Drupal\Core\Field\FieldDefinitionInterface $field_definition, $view_mode, $form, \Drupal\Core\Form\FormStateInterface $form_state) {
+ $element = [];
+ // Add a 'my_setting' checkbox to the settings form for 'foo_formatter' field
+ // formatters.
+ if ($plugin->getPluginId() == 'foo_formatter') {
+ $element['my_setting'] = [
+ '#type' => 'checkbox',
+ '#title' => t('My setting'),
+ '#default_value' => $plugin->getThirdPartySetting('my_module', 'my_setting'),
+ ];
+ }
+ return $element;
+}