How to hide language switcher block if node has no translation?
In template.php add:

/**
 * hide language switcher if en-gb is not set
 */
function MYTHEME_links__locale_block(&amp;$vars) {
  // made conditional if other languages are added later
  if(!isset($vars['links']['en-gb']['href'])) {
    unset($vars['links']['en-gb']);
  }
  // here is the condition
  if(count($vars['links']) &lt;= 1) {
    return '';
  } else {
    return theme_links($vars);
  }
}