custom_glue.module

<?php
/**
 * @file custom_glue.module
 * TODO: Enter file description here.
 */
function custom_glue_preprocess_html(&$variables) {
  $glue = drupal_get_path('module', 'custom_glue') . '/custom_glue.css';

  $options = array(
    'group' => CSS_THEME + 1,
    'weight' => 99,
  );

  drupal_add_css($glue, $options);
}

function custom_glue_form_alter(&$form, $form_state, $form_id) {
  switch ($form_id) {
   
   case 'comment_node_wiki_page_form':
     dpm($form);
     /*
      $criteria = array();
      $criteria['entity_id'] = $form['#entity']->nid;
      $criteria['uid'] = votingapi_current_user_identifier();

      // check if current user has already voted for this node:
      $vote =  votingapi_select_votes($criteria, 1);

      if(!empty($vote)){
        // user has already voted: hide rating field:
        unset($form['field_vote']);
      }
*/
      break;

  }
}


function custom_glue_comment_view($comment, $view_mode, $langcode) {

  // if a comment has the rating field:
  if(isset($comment->field_vote)) {
    
    // If user has not voted on this comment:
    if($comment->field_vote['und'][0]['count'] == 0) {
      
      // hide rating field:
      unset($comment->content['field_vote']);  
    
    }
  }
}