ISTWCMS-2452: Create _uw_fdsu_theme_resp_get_image_info()

uw_fdsu_theme_resp.theme

@@ -319,3 +319,26 @@ function _uw_fdsu_theme_resp_add_responsive_image_variables(array &$variables, $
     return $new_sources;
   }
 }
+
+/**
+ * Get image properties from an image field.
+ *
+ * @param object $field
+ *   The image field.
+ *
+ * @return array|null
+ *   An array of image properties or NULL if $field does not contain the
+ *   required information.
+ */
+function _uw_fdsu_theme_resp_get_image_info(Drupal\file\Plugin\Field\FieldType\FileFieldItemList $field) {
+  // If there is an image, process it.
+  if ($img_entity = $field->first()) {
+    // If we can load a file, grab the info about the file.
+    if ($file_entity = $img_entity->get('entity')->getTarget()) {
+      return [
+        'src' => file_create_url($file_entity->get('uri')->getString()),
+        'alt' => $img_entity->get('alt')->getString(),
+      ];
+    }
+  }
+}