File / Image Field Diff Integration

idk if images are purged from the filesystem upon node deletion or revision, but i would assume that they are not. So the revision could call upon the images still OR maybe (if they are deleted) this module could move them into a new directory upon revision. The diff should show at a minimum that the field has changed values, but the image saving should not be hard to setup. The revision deletion module http://drupal.org/project/revision_deletion will be important with image diff support (since it would need to delete files associated with revisions).

Just noting something I did by overriding a diff theme function.

This is for 6.x but probably works for 7.x with some adjustments.

It's also a work in progress, this is just something custom I did that I thought I might share:

Note, I am using an imagecache preset, but it can use just theme('image'), you need to remove the preset though if you use that instead.

/**
 * Theme function for a content line in the diff.
 */
function THEME_diff_content_line($line) {
  $line = filter_xss($line);
  $filespath = str_replace('/', '\/', file_create_path());
  if (preg_match("/($filespath.*)(.jpg|.png|.gif|.bmp)/i", $line, $matches)) {
    unset($matches[0]);
    $img = implode('', $matches);
    $output = '<div>' . theme('imagecache', '100x200', $img, $img, $img) . '</div>';
  }
  else {
    $output = '<div>'. $line .'</div>';
  }

  return $output;
}

I think this should be a major request.

For multi-user sites it would be extremely important to know when images were changed / removed / added.
Moving the files after a revision would be helpful, but not necessarily essential. For example one could move removed files into a sub_folder or simply prepend something to the file name. Of course then the db table 'file_managed' would need to update the filename aswell as the uri fields.

I tried the above code in my themes template.php file - I do use drupal 7 - I changed the output line for correct image cache formatting in d7, but it doesn't work at all when images are changed / added / deleted ..

I use the default thumbnail preset as it is not possible to delete this.

/**
* Theme function for a content line in the diff.
*/
function YOURTHEME_diff_content_line($line) {
  $line = filter_xss($line);
  $filespath = str_replace('/', '\/', file_create_path());
  if (preg_match("/($filespath.*)(.jpg|.png|.gif|.bmp)/i", $line, $matches)) {
    unset($matches[0]);
    $img = implode('', $matches);
    $output = '<div>' . image_style_url('thumbnail', $img) . '</div>';
  }
  else {
    $output = '<div>'. $line .'</div>';
  }

  return $output;
}

This is fixed in 7.x-3.x.