drupal/core/modules/file/file.api.php

220 lines
6.2 KiB
PHP

<?php
/**
* @file
* Hooks for file module.
*/
/**
* Load additional information into file entities.
*
* file_load_multiple() calls this hook to allow modules to load
* additional information into each file.
*
* @param $files
* An array of file entities, indexed by fid.
*
* @see file_load_multiple()
* @see file_load()
*/
function hook_file_load($files) {
// Add the upload specific data into the file entity.
$result = db_query('SELECT * FROM {upload} u WHERE u.fid IN (:fids)', array(':fids' => array_keys($files)))->fetchAll(PDO::FETCH_ASSOC);
foreach ($result as $record) {
foreach ($record as $key => $value) {
$files[$record['fid']]->$key = $value;
}
}
}
/**
* 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.
*
* @param Drupal\file\File $file
* The file entity being validated.
* @return
* An array of error messages. If there are no problems with the file return
* an empty array.
*
* @see file_validate()
*/
function hook_file_validate(Drupal\file\File $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;
}
/**
* Act on a file being inserted or updated.
*
* This hook is called when a file has been added to the database. The hook
* doesn't distinguish between files created as a result of a copy or those
* created by an upload.
*
* @param Drupal\file\File $file
* The file entity that is about to be created or updated.
*/
function hook_file_presave(Drupal\file\File $file) {
// Change the file timestamp to an hour prior.
$file->timestamp -= 3600;
}
/**
* Respond to a file being added.
*
* This hook is called after a file has been added to the database. The hook
* doesn't distinguish between files created as a result of a copy or those
* created by an upload.
*
* @param Drupal\file\File $file
* The file that has been added.
*/
function hook_file_insert(Drupal\file\File $file) {
// Add a message to the log, if the file is a jpg
$validate = file_validate_extensions($file, 'jpg');
if (empty($validate)) {
watchdog('file', 'A jpg has been added.');
}
}
/**
* Respond to a file being updated.
*
* This hook is called when an existing file is saved.
*
* @param Drupal\file\File $file
* The file that has just been updated.
*/
function hook_file_update(Drupal\file\File $file) {
}
/**
* Respond to a file that has been copied.
*
* @param Drupal\file\File $file
* The newly copied file entity.
* @param Drupal\file\File $source
* The original file before the copy.
*
* @see file_copy()
*/
function hook_file_copy(Drupal\file\File $file, Drupal\file\File $source) {
}
/**
* Respond to a file that has been moved.
*
* @param Drupal\file\File $file
* The updated file entity after the move.
* @param Drupal\file\File $source
* The original file entity before the move.
*
* @see file_move()
*/
function hook_file_move(Drupal\file\File $file, Drupal\file\File $source) {
}
/**
* Act prior to file deletion.
*
* This hook is invoked when deleting a file before the file is removed from the
* filesystem and before its records are removed from the database.
*
* @param Drupal\file\File $file
* The file that is about to be deleted.
*
* @see hook_file_delete()
* @see Drupal\file\FileStorageController::delete()
* @see upload_file_delete()
*/
function hook_file_predelete(Drupal\file\File $file) {
// Delete all information associated with the file.
db_delete('upload')->condition('fid', $file->fid)->execute();
}
/**
* Respond to file deletion.
*
* This hook is invoked after the file has been removed from
* the filesystem and after its records have been removed from the database.
*
* @param Drupal\file\File $file
* The file that has just been deleted.
*
* @see hook_file_predelete()
* @see Drupal\file\FileStorageController::delete()
*/
function hook_file_delete(Drupal\file\File $file) {
// Delete all information associated with the file.
db_delete('upload')->condition('fid', $file->fid)->execute();
}
/**
* Control download access to files.
*
* The hook is typically implemented to limit access based on the entity that
* references the file; for example, only users with access to a node should be
* allowed to download files attached to that node.
*
* @param $field
* The field to which the file belongs.
* @param Drupal\entity\EntityInterface $entity
* The entity which references the file.
* @param Drupal\file\File $file
* The file entity that is being requested.
*
* @return
* TRUE is access should be allowed by this entity or FALSE if denied. Note
* that denial may be overridden by another entity controller, making this
* grant permissive rather than restrictive.
*
* @see hook_field_access().
*/
function hook_file_download_access($field, Drupal\entity\EntityInterface $entity, Drupal\file\File $file) {
if ($entity->entityType() == 'node') {
return node_access('view', $entity);
}
}
/**
* Alter the access rules applied to a file download.
*
* Entities that implement file management set the access rules for their
* individual files. Module may use this hook to create custom access rules
* for file downloads.
*
* @see hook_file_download_access().
*
* @param $grants
* An array of grants gathered by hook_file_download_access(). The array is
* keyed by the module that defines the entity type's access control; the
* values are Boolean grant responses for each module.
* @param array $context
* An associative array containing the following key-value pairs:
* - field: The field to which the file belongs.
* - entity: The entity which references the file.
* - file: The file entity that is being requested.
*
* @see hook_file_download_access().
*/
function hook_file_download_access_alter(&$grants, $context) {
// For our example module, we always enforce the rules set by node module.
if (isset($grants['node'])) {
$grants = array('node' => $grants['node']);
}
}