function hook_file_validate

7.x system.api.php hook_file_validate($file)
8.x file.api.php hook_file_validate(Drupal\file\FileInterface $file)

Check that files meet a given criteria.

This hook lets modules perform additional validation on files. They're able to report a failure by returning one or more error messages.


$file: The file object being validated.

Return value

An array of error messages. If there are no problems with the file return an empty array.

See also


Related topics

2 functions implement hook_file_validate()

Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.

file_managed_file_validate in drupal/modules/file/file.module
An #element_validate callback for the managed_file element.
file_test_file_validate in drupal/modules/simpletest/tests/file_test.module
Implements hook_file_validate().
1 invocation of hook_file_validate()
file_validate in drupal/includes/
Checks that a file meets the criteria specified by the validators.


drupal/modules/system/system.api.php, line 2831
Hooks provided by Drupal core and the System module.


function hook_file_validate($file) {
  $errors = array();

  if (empty($file->filename)) {
    $errors[] = t("The file's name is empty. Please give a name to the file.");
  if (strlen($file->filename) > 255) {
    $errors[] = t("The file's name exceeds the 255 characters limit. Please rename the file and try again.");

  return $errors;