WordPress snippet: add uploadable file types

uploadables.php

/**
 * Add uploadable mime types / file extensions
 */
function dc_add_uploadables($arr = array()) {
  $new = array(
    // Add file extension => mime type mapping here
    'keynote|key' => 'application/vnd.apple.keynote',
    'numbers' => 'application/vnd.apple.numbers',
    'pages' => 'application/vnd.apple.pages'
  );

  $arr = array_merge($arr, $new);
  
  return $arr;
}

if ( function_exists( 'wp_get_mime_types' ) ) {
  // @since WordPress 3.5.0
  add_filter('mime_types', 'dc_add_uploadables');
} else {
  add_filter('upload_mimes', 'dc_add_uploadables');
}