README.md

Munge a form field into a multiple select (and back!)

This is a sample Drupal module that modifies an existing form field to display it as a multiple select without having to modify the handling code. As far as the form's "owner" is concerned, the user enters a comma-separated list of values.

The goal is, as you can probably tell from the $form_id, to turn a profile field into a multiple select of values from elsewhere. This is probably less than ideal, but I can't figure out a better way to achieve this.

munge.module

<?php

/**
 * Attempt to do strange things to the profile edit form.
 */
function munge_form_alter(&$form, &$form_state, $form_id)
{
  if ('user_profile_form' == $form_id) {
    $form['test']['profile_ids']['#process'] = array('munge_into_multiselect');
  }
}

function munge_into_multiselect($element)
{

  $data = array('one', 'two', 'miss', 'a few', '99', 'one hundred');

  if (count($element['#post'])>0) {
    
    // Turn it back into a text-field so that it'll save

    $selected = $element['#value'];

    $element['#value'] = implode(',', $selected);
    
  } else {
    
    // Turn it into a multiple select    

    $selected = explode(',', $element['#value']);

    $element['#type'] = 'select';
    $element['#multiple'] = TRUE;
    $element['#options'] = $data;
    $element['#value'] = $selected;
  }
  
  return $element;
}