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

9 calls to file_usage_add()

FileDeleteTest::testInUse in modules/simpletest/tests/file.test

Tries deleting a file that is in use.

FileUsageTest::testAddUsage in modules/simpletest/tests/file.test

Tests file_usage_add().

file_field_insert in modules/file/file.field.inc

Implements hook_field_insert().

file_field_update in modules/file/file.field.inc

Implements hook_field_update().

image_field_update_field in modules/image/image.module

Implements hook_field_update_field().

... See full list

File

includes/file.inc, line 713

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 ();
}

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