function hook_file_type_alter

1 file.api.php hook_file_type_alter(array &$types, $file)

Alters list of file types that can be assigned to a file.

array $types: List of proposed types.

object $file: File object.

2 invocations of hook_file_type_alter()

file_get_filetype_candidates in core/modules/file/file.pages.inc: Get the candidate filetypes for a given file.
file_get_type in core/modules/file/file.module: Determines file type for a given file.

function hook_file_type_alter(array &$types, $file) {
  // Choose a specific, non-first, file type.
  $types = array($types[4]);
}