crm.fsf.org/20131203/files/modules/file/file.api.php

   1 <?php
   2
   3 /**
   4  * @file
   5  * Hooks for file module.
   6  */
   7
   8 /**
   9  * Control download access to files.
  10  *
  11  * The hook is typically implemented to limit access based on the entity the
  12  * file is referenced, e.g., only users with access to a node should be allowed
  13  * to download files attached to that node.
  14  *
  15  * @param array $file_item
  16  *   The array of information about the file to check access for.
  17  * @param $entity_type
  18  *   The type of $entity; for example, 'node' or 'user'.
  19  * @param $entity
  20  *   The $entity to which $file is referenced.
  21  *
  22  * @return
  23  *   TRUE is access should be allowed by this entity or FALSE if denied. Note
  24  *   that denial may be overridden by another entity controller, making this
  25  *   grant permissive rather than restrictive.
  26  *
  27  * @see hook_field_access().
  28  */
  29 function hook_file_download_access($file_item, $entity_type, $entity) {
  30   if ($entity_type == 'node') {
  31     return node_access('view', $entity);
  32   }
  33 }
  34
  35 /**
  36  * Alter the access rules applied to a file download.
  37  *
  38  * Entities that implement file management set the access rules for their
  39  * individual files. Module may use this hook to create custom access rules
  40  * for file downloads.
  41  *
  42  * @see hook_file_download_access().
  43  *
  44  * @param $grants
  45  *   An array of grants gathered by hook_file_download_access(). The array is
  46  *   keyed by the module that defines the entity type's access control; the
  47  *   values are Boolean grant responses for each module.
  48  * @param array $file_item
  49  *   The array of information about the file to alter access for.
  50  * @param $entity_type
  51  *   The type of $entity; for example, 'node' or 'user'.
  52  * @param $entity
  53  *   The $entity to which $file is referenced.
  54  */
  55 function hook_file_download_access_alter(&$grants, $file_item, $entity_type, $entity) {
  56   // For our example module, we always enforce the rules set by node module.
  57   if (isset($grants['node'])) {
  58     $grants = array('node' => $grants['node']);
  59   }
  60 }