Custom prefix for each value of a multi-value field

Question

I have a number field where a user needs to enter two values. Each value should have a custom prefix but that isn't possible within the field settings.

Does anybody know how this can be done? Thanks.

Answer 1

That's how you can add prefixes to node output (replace view_mode and field_name to yours):

/**
 * Implements hook_preprocess_field().
 */
function mymodule_preprocess_field(&$vars) {
  if ($vars['element']['#entity_type'] == 'node' &&
      $vars['element']['#view_mode'] == 'full' &&
      $vars['element']['#field_name'] == 'field_number') {

    $vars['items'][0]['#markup'] = '<span>$</span>' . $vars['items'][0]['#markup'];
    $vars['items'][1]['#markup'] = '<span>€</span>' . $vars['items'][1]['#markup'];
  }
}

Answer 2

You can use form_alter function to do it:

/**
 * Implements hook_form_alter().
 */
function your_module_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'article_node_form') {
    $form['field_number'][LANGUAGE_NONE][0]['value']['#prefix'] = '$';
    $form['field_number'][LANGUAGE_NONE][1]['value']['#prefix'] = '€';
  }
}