Taxonomy field in right column on node edit form

The code is in there it's just not working as expected. The problem is this block of code in the template.php around line 202:

  // Default to showing taxonomy in sidebar if nodeformcols is not present.
  elseif (isset($vars['form']['taxonomy']) && empty($vars['sidebar'])) {
    $vars['sidebar']['taxonomy'] = $vars['form']['taxonomy'];
    unset($vars['form']['taxonomy']);
  }

The condition doesn't fire because in that form array there isn't a taxonomy like it used to be in D6 (at the top of the function add a dpm($vars); to see what I'm talking about) if you wanted it to work you can create a sub theme and refine the function and that condition and assign your taxonomy fields to that sidebar variable or you could try just using the nodeformcols module.

I also need this.

For now I just implemented a sub theme.

And in my subtheme template.php added this.

<?php
/** 
 * Implement hook_theme().
 *
 * Need this to add our custom preprocess function to rubik default node_form theming.
 */
function my_sub_rubik_theme() {
  $items = array();

  $items['node_form'] = array(
    'render element' => 'form',
    'path' => drupal_get_path('theme', 'rubik') .'/templates',
    'template' => 'form-default',
    'preprocess functions' => array(
      'rubik_preprocess_form_buttons',
      'rubik_preprocess_form_node',
      'my_sub_rubik_preprocess_form_node', // Make sure our preprocess function is called
    ),
  );

  return $items;
}

/**
 * Preprocessor for theme('node_form').
 */
function my_sub_rubik_preprocess_form_node(&$vars) {
  // I have a custom field group call categories. So I look for $vars['form']['group_categories']
  if (isset($vars['form']['group_categories']) && empty($vars['sidebar'])) {
    $vars['sidebar']['group_categories'] = $vars['form']['group_categories'];
    unset($vars['form']['group_categories']);
  }
}
?>

Solve my issues. Also now I can add anything I want from that form on the sidebar.

Feature added in #1626886: Make sidebar sticky and add sidebar field option