How do you load extra javascript files required for wysiwyg api plugin on node/edit pages?
With drupal_add_js:

function yourmodule_preprocess_page(&amp;$vars)
{
  $node = $vars['node']; 
  if($node-&gt;type == 'yournodetype' AND arg(2) == 'edit')
  {
    drupal_add_js([...]);
  }
}