How to download a file from private file system

Question

I need a function in my module for users to download a file from a private filesystem.

$file : "private://sample.csv"

Which function should be used, file_download(), or file_transfer()?

function file_download_page() {
  $file = "private://sample.csv";
  //code for downloading $file
}    

Please provide sample code.

Answer 1

You just need to call file_create_url().

It will return an URL that will go through Drupal which will then check the appropriate permiss (if you need custom checks, you need to implement hook_file_download)

Answer 2

I use hook_file_download_access:

/**
 * Implement hook_file_download_access().
 */
function YOURMODULENAME_file_download_access($file_item, $entity_type, $entity) {
  global $user;
  return (in_array('hr', $user->roles) || in_array('administrator', $user->roles)) ? TRUE : FALSE;
}

Answer 3

Using DownloadFile you can download the file. I am using this module