--- /dev/null
+<?php
+
+namespace Drupal\file_mdm\Element;
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element\FormElement;
+
+/**
+ * Implements a form element to enable capturing cache information for file_mdm.
+ *
+ * @FormElement("file_mdm_caching")
+ */
+class FileMetadataCaching extends FormElement {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getInfo() {
+ $class = get_class($this);
+ return [
+ '#input' => TRUE,
+ '#process' => [[$class, 'processCaching']],
+ '#element_validate' => [[$class, 'validateCaching']],
+ ];
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
+ if ($input !== FALSE && $input !== NULL) {
+ $disallowed_paths = $input['disallowed_paths'];
+ if (!empty($disallowed_paths)) {
+ $disallowed_paths = preg_replace('/\r/', '', $disallowed_paths);
+ $disallowed_paths = explode("\n", $disallowed_paths);
+ while (empty($disallowed_paths[count($disallowed_paths) - 1])) {
+ array_pop($disallowed_paths);
+ }
+ $input['disallowed_paths'] = $disallowed_paths ?: [];
+ }
+ else {
+ $input['disallowed_paths'] = [];
+ }
+ return $input;
+ }
+ return NULL;
+ }
+
+ /**
+ * Processes a 'file_mdm_caching' form element.
+ *
+ * @param array $element
+ * The form element to process.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ * The current state of the form.
+ * @param array $complete_form
+ * The complete form structure.
+ *
+ * @return array
+ * The processed element.
+ */
+ public static function processCaching(array &$element, FormStateInterface $form_state, array &$complete_form) {
+ $element['enabled'] = [
+ '#type' => 'checkbox',
+ '#title' => t('Cache metadata'),
+ '#default_value' => $element['#default_value']['enabled'],
+ '#description' => t("If selected, metadata retrieved from files will be cached for further access."),
+ ];
+ $options = [86400, 172800, 604800, 1209600, 3024000, 7862400];
+ $options = array_map([\Drupal::service('date.formatter'), 'formatInterval'], array_combine($options, $options));
+ $options = [-1 => t('Never')] + $options;
+ $element['expiration'] = [
+ '#type' => 'select',
+ '#title' => t('Cache expires'),
+ '#default_value' => $element['#default_value']['expiration'],
+ '#options' => $options,
+ '#description' => t("Specify the required lifetime of cached entries. Longer times may lead to increased cache sizes."),
+ '#states' => [
+ 'visible' => [
+ ':input[name="' . $element['#name'] . '[enabled]"]' => array('checked' => TRUE),
+ ],
+ ],
+ ];
+ $element['disallowed_paths'] = [
+ '#type' => 'textarea',
+ '#title' => t('Excluded paths'),
+ '#rows' => 3,
+ '#default_value' => implode("\n", $element['#default_value']['disallowed_paths']),
+ '#description' => t("Only files prefixed by a valid URI scheme will be cached, like for example <kbd>public://</kbd>. Files in the <kbd>temporary://</kbd> scheme will never be cached. Specify here if there are any paths to be additionally <strong>excluded</strong> from caching, one per line. Use wildcard patterns when entering the path. For example, <kbd>public://styles/*</kbd>."),
+ '#states' => [
+ 'visible' => [
+ ':input[name="' . $element['#name'] . '[enabled]"]' => array('checked' => TRUE),
+ ],
+ ],
+ ];
+
+ return $element;
+ }
+
+ /**
+ * Form element validation handler.
+ */
+ public static function validateCaching(&$element, FormStateInterface $form_state, &$complete_form) {
+ // Validate cache exclusion paths.
+ foreach ($element['#value']['disallowed_paths'] as $path) {
+ if (!file_valid_uri($path)) {
+ $form_state->setError($element['disallowed_paths'], t("'@path' is an invalid URI path", ['@path' => $path]));
+ }
+ }
+ }
+
+}