Invalid argument supplied for foreach() With Token and Automatic Nodetitles

I get the same error on node submit, in combination with CCK filefield and filefield_paths. I know filefield and/or filefield_paths must have something to do with it, because: when I submit a node without a filefield, everthing works fine. Also, when I submit a node with a filefield, but don't actually upload a file (leave filefield empty), everything works fine.

The warning originates in nodehierarchy_token.inc on line 22 ("if ($parent = node_load($node->parent)) {") :

function nodehierarchy_token_values($type, $object = NULL, $options = array()) {
  $tokens = array();
  if ($type == 'node') {
    $node = $object;
    $tokens['hierarchyparentnid']          = (int)$node->parent;
    $tokens['hierarchytitlepath']          = nodehierarchy_token_get_hierarchytitlepath($node);
    $tokens['fullhierarchytitlepath']      = nodehierarchy_token_get_fullhierarchytitlepath($node);
    $tokens['hierarchytitlepath-raw']      = nodehierarchy_token_get_hierarchytitlepath($node, TRUE);
    $tokens['fullhierarchytitlepath-raw']  = nodehierarchy_token_get_fullhierarchytitlepath($node, TRUE);
    $tokens['hierarchypath']               = nodehierarchy_token_get_hierarchypath($node);
    $tokens['fullhierarchypath']           = nodehierarchy_token_get_fullhierarchypath($node);

    if ($parent = node_load($node->parent)) {
      $tokens['hierarchyparenttitle']        = check_plain(@$parent->title);
      $tokens['hierarchyparenttitle-raw']    = @$parent->title;
    }
    else {
      $tokens['hierarchyparenttitle']        = '';
      $tokens['hierarchyparenttitle-raw']    = '';
    }
  }
  return $tokens;
}

$node->parent is probably NULL and thus, the node_load function generates a warning.

Funny thing is, while these functions are called for both admins and normal users, the warning is only displayed for normal users! Even though when admin, $node->parent is also NULL !

I suggest a check to see if $node->parent is null before calling node_load. But I don't know if that's just fixing the symptom and not the real problem... See, I'm not sure why nodehierarchy_token_values is called on a content type that isn't set up as parent, nor as child...

See, I'm not sure why nodehierarchy_token_values is called on a content type that isn't set up as parent, nor as child...

Ok, I just got thinking: calling this function is normal, and is used by another module (like filefield_paths) to get all possible replacement tokens from this module (and likely does it for all other modules as well). Weather or not it actually uses them.

So I think that, the fact that $node->parent can be NULL at this point was just not expected by the programmer. Since, perhaps, he only expected this function to be called in a nodehierarchy context?

So the best solution would, indeed, be to check if $node->parent is NULL, before calling node_load?

Is my reasoning correct?

I have the same error with Automatic Nodetitle but without Node Hierarchy installed.

That could very well be. It's very likely that other module developers also call node_load without checking if it's first parameter is not null.

You could say the problem lays with node_load and that IT should check if it's first parameter is null or not. Someone seems to have suggest just that: http://drupal.org/node/102030 . But since there hasn't been any reaction on that issue report since December 30, 2006, I guess that Drupal core developers expect the module developers to check the params they give to node_load...

Which brings us back to my question:

So the best solution would, indeed, be to check if $node->parent is NULL, before calling node_load?

I ran across that one myself recently. I'll get it patched as soon as I can.

R

Thanks Ronan! I can submit a patch for it, but it's so trivial, I think it would only waste your time :)

Ok, should be good in the latest 5.x-1.x-dev. Thanks for all your patience.