How do I make the administrative UI feel like Joomla? I am working on a way to make a node/add/article page like joomla but but by now I haven't got any remarkable result. 
I've written this code to hide a part and print it in another part:

function MYMODULE_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  $form['revision_information']['#type'] = 'hidden';
}


but I need to di it in preprosess time in order to have more performance.
so I use this one:

in .module file:

function template_preprocess_article_node_form(&amp;$variables) {
  if (!module_exists('nodeformcols')) {
      hide($variables['form']['additional_settings']);
   }
}


in article-node-form.tpl.php

&lt;div class="node-add-wrapper clear-block"&gt;
  &lt;div class="node-column-sidebar"&gt;
    &lt;?php if($sidebar): ?&gt;
      &lt;?php print render($sidebar); print_r($variables['form']['comment_settings']);//['additional_settings'])?&gt;
    &lt;?php endif; ?&gt;
  &lt;/div&gt;




but I don't have access to all field in this way.
any alternative or simpler approach will be appreciated.
You were going in the right direction with:

function MYMODULE_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  $form['revision_information']['#type'] = 'hidden';
}


However, you have a bug in that code. The code above will modify every form. Instead, use hook_form_FORM_ID_alter to target the specific form.