<?php
// $Id: upload.inc,v 1.3 2007-06-06 18:11:47 dww Exp $

/**
 * Implementation of hook_diff() for file attachments.
 */
function upload_diff(&$old_node, &$new_node) {
  $result = array();
  $old_files = array();
  if (isset($old_node->files)) {
    foreach($old_node->files as $file) {
      $old_files[] = $file->filename;
    }
  }
  $new_files = array();
  if (isset($new_node->files)) {
    foreach($new_node->files as $key => $file) {
      if (is_array($file)) {
        // During editing the files are stored as arrays, not objects.
        if ($file['remove']) {
          // It looks better if a blank line is inserted for removed files.
          $new_files[] = '';
        }
        else {
          $new_files[] = $file['filename'];
        }
      }
      else {
        $new_files[] = $file->filename;
      }
    }
  }
  $result[] = array(
    'name' => t('Attachments'),
    'old' => $old_files,
    'new' => $new_files,
    'format' => array(
      'show_header' => false,
    )
  );
  return $result; 
}