cant get file uri using field preprocess

Question

Im trying to use function theme_preprocess_field to get the file path of a file field.

I have tried different variations of below.

  function mytheme_preprocess_field(&$variables) {
    if ($variables['element']['#field_name'] == 'my_file_field') {
      $uri = \Drupal\file\Entity\File::load($variables['items'][0]['content']['#item']->getValue())->getFileUri();
      $variables['my_file_field_path'] = $uri;
    }
  }

In my instance it says value null, but it isn't.

How can I get the file path of my_file_field? Thanks

Answer 1

In a template don't use a content variable to get references to objects. This is what the template is rendering. The structure depends on the field formatter and its configuration. Use it only if you want to change this rendered output.

For object references use element(s), unless you find a dedicated variable in the Twig doc block.

function mytheme_preprocess_field(&$variables) {
  $element = $variables['element'];
  if ($element['#field_name'] == 'my_file_field') {
    $items = $element['#items'];
    if (!$items->isEmpty()) {
      $file = $items[0]->entity;
      if ($file instanceof \Drupal\file\Entity\File) {
        $uri = $file->getFileUri();
      }
    }
  }
}