My radio buttons don't show

Question

I have tried to set up an online example of a form using Drupal 7.

When I run it, the radio buttons do not show at all.
I also get the following errors:

Notice: Undefined index: #title_display in form_pre_render_conditional_form_element() (line 3090 of /var/www/sandbox7/includes/form.inc).
Notice: Undefined index: #title_display in form_pre_render_conditional_form_element() (line 3090 of /var/www/sandbox7/includes/form.inc).
Notice: Undefined index: #id in drupal_process_states() (line 4549 of /var/www/sandbox7/includes/common.inc).
Notice: Undefined index: #id in drupal_process_states() (line 4549 of /var/www/sandbox7/includes/common.inc).
Notice: Undefined index: #id in drupal_process_states() (line 4549 of /var/www/sandbox7/includes/common.inc).

Answer 1

Is the form running through drupal_get_form? This type of error can occur when using the generic render() fuction on a form that hasn't been prepared by drupal_get_form(). Check your hook_menu settings and make sure your page callback is set to drupal_get_form() with the form id as the page arguments(encapsulated in an array)

if you must use a custom page callback, make sure that you're piping the form based output through drupal_get_form() like so...

$output = drupal_get_form('form_id');

Answer 2

ok the correct form for do it this is this

   $items['examples/form_example/states'] = array(
    'title' => '#states example',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('form_example_states_form'),
    'access callback' => TRUE,
    'description' => 'How to use the #states attribute in FAPI',
    'file' => 'form_example_states.inc',
  );

the wrong form is this

   $items['examples/form_example/states'] = array(
    'title' => '#states example',
    'page callback' => 'form_example_states_form',
    'access callback' => TRUE,
    'description' => 'How to use the #states attribute in FAPI',
    'file' => 'form_example_states.inc',
  );

and working :)