How can I sort a View's exposed filter options alphabetically?

Question

I have a custom module which uses hook_form_views_exposed_form_alter() to sort the options of a select list into alphabetical order.

This appears to work because dmp($form) shows $form['field_keywords_tid']['#options'] to be in alphabetical order, but when checking the select list the order is different.

You can see the view and the dpm() output on the dev site.

My code so far is:

function dependant_keyword_filter_form_views_exposed_form_alter(&$form, &$form_state) {
  if ($form['#id'] == 'views-exposed-form-annotated-bibliography-page') {
    foreach ($form_state['view']->filter as $field => $filter) {
      if ($filter->options['exposed']  && $filter->options['id'] == 'field_keywords_tid' ) {
        $field_id = $form['#info']['filter-field_keywords_tid']['value'];
        asort($form[$field_id]['#options']);
      }
    }
    dpm($form);
  }
}

I thought I needed to replace $form['filter-field_keywords_tid']['#options'] with the sorted array so I tried the following code after the foreach above, but this didn't work either.

$options = array('All' => '- Any -');
foreach ($form[$field_id]['#options'] as $key => $val) {
  $options[$key] = $val;
}
$form['field_keywords_tid']['#options'] = $options;

I also tried the code below found in this Drupal Answers post with the same result. dpm() output sorted but select list not.

foreach ($form_state['view']->filter as $filter) {
  if($fid = $filter->options['expose']['identifier']) {
    asort($form[$fid]['#options']);
  }
}

I'd appreciate any suggestions.

Answer 1

J. Reynolds suggestion was the answer.

Creating a new function for the sort code and using $form['#after_build'] to call it resulted in the select box being sorted alphabetically.

function dependant_keyword_filter_form_views_exposed_form_alter(&$form, &$form_state){
if ($form['#id'] == 'views-exposed-form-annotated-bibliography-page') {
    $form['#after_build'][] = '_sort_alphabetically';
  }
}
function _sort_alphabetically($form, $form_state) {
        foreach ($form_state['view']->filter as $field => $filter) {
            if ($filter->options['exposed']  && $filter->options['id'] == 'field_keywords_tid' ) {
                $field_id = $form['#info']["filter-field_keywords_tid"]['value'];
                asort($form[$field_id]['#options']);
            }
        }
        return $form;
}