Respond to a file being updated.
This hook is called when an existing file is saved.
Drupal\file\File $file: The file that has just been updated.
Note: this list is generated by pattern matching, so it may include some functions that are not actually implementations of this hook.
function hook_file_update(Drupal\file\File $file) {
$file_user = user_load($file->uid);
// Make sure that the file name starts with the owner's user name.
if (strpos($file->filename, $file_user->name) !== 0) {
$old_filename = $file->filename;
$file->filename = $file_user->name . '_' . $file->filename;
$file
->save();
watchdog('file', t('%source has been renamed to %destination', array(
'%source' => $old_filename,
'%destination' => $file->filename,
)));
}
}