function file_usage_add

Records that a module is using a file.

This usage information will be queried during file_delete() to ensure that a file is not in use before it is physically removed from disk.

Examples:

  • A module that associates files with nodes, so $type would be 'node' and $id would be the node's nid. Files for all revisions are stored within a single nid.
  • The User module associates an image with a user, so $type would be 'user' and the $id would be the user's uid.

Parameters

$file: A file object.

$module: The name of the module using the file.

$type: The type of the object that contains the referenced file.

$id: The unique, numeric ID of the object containing the referenced file.

$count: (optional) The number of references to add to the object. Defaults to 1.

See also

file_usage_list()

file_usage_delete()

Related topics

File interface
Common file handling functions.
9 calls to file_usage_add()
FileDeleteTest::testInUse in drupal/modules/simpletest/tests/file.test
Tries deleting a file that is in use.
FileUsageTest::testAddUsage in drupal/modules/simpletest/tests/file.test
Tests file_usage_add().
file_field_insert in drupal/modules/file/file.field.inc
Implements hook_field_insert().
file_field_update in drupal/modules/file/file.field.inc
Implements hook_field_update().
image_field_update_field in drupal/modules/image/image.module
Implements hook_field_update_field().

... See full list

File

drupal/includes/file.inc, line 699
API for handling file uploads and server file management.

Code

function file_usage_add(stdClass $file, $module, $type, $id, $count = 1) {
  db_merge('file_usage')
    ->key(array(
    'fid' => $file->fid,
    'module' => $module,
    'type' => $type,
    'id' => $id,
  ))
    ->fields(array(
    'count' => $count,
  ))
    ->expression('count', 'count + :count', array(
    ':count' => $count,
  ))
    ->execute();
}