Remove empty options in exposed filters

Question

I have an exposed filter with a select options drop-down field that collects all the actual values in my current view. Unfortunately it also collects and displays the empty fields in my view.

I have tried to create a module that handles this, but I cannot make it to actually update my current exposed filters. Any suggestions?

function remove_duplicated_publications_form_alter(&$form, &$form_state, $form_id) {
  if($form_id == 'views_exposed_form'){
    foreach($form as $tmp){
      if ($tmp["#type"]=="select"){
        foreach($tmp["#options"] as $tjek){
          if ($tjek==NULL){
            unset ($tmp["#options"][$tjek]);
          }
        }
      }
    }
  } 
}

--- SOLUTION FOUND !! --- I needed to unset the $form array instead. The following code works:

function remove_duplicated_publications_form_alter(&$form) {
  foreach($form['#info'] as $field){
    $field_id = $field['value'];
    if ($form[$field_id]["#type"]=="select"){
      foreach($form[$field_id]["#options"] as $optionvalue){
        if ($optionvalue==NULL){
          unset ($form[$field_id]["#options"][$optionvalue]);
        }
      }
    }
  }
}

Answer 1

Use array_walk() in conjunction with unset()